Scientific papers

List of papers published by FBSHEE reserchers is presented at WUT respository

Andrzej Martyszunis, Małgorzata Loga & Karol Przeździecki Advancements in Artificial Intelligence (AI) technology allow for development of new tools for analytics and management which present new opportunities in field of environmental protection. The following study showcases usage of Machine Learning (ML) techniques as a complementary method for water status assessment of water bodies. Since the main goal of Water Framework Directive (WFD) is to improve the quality of water and reach good status in all the water bodies across Europe intensive monitoring program was launched together with water status assessment procedure. Based on requirements of the European Union’s WFD concerning ecological status assessment it is presented how ML can be used for assessment of Polish unmonitored river water bodies. Due to the absence of monitoring data, the foremost challenge lay in securing relevant alternative data which was set to be anthropogenic pressures. The pivotal solution was implementation of ML techniques which enable processing of seemingly unrelated information concerning pressures in the catchment. Decision Tree, Random Forest, KNN, Support Vector Machine, Multinomial Naive Bayes, XGBoost models have been tested and the results indicated most suitable techniques. Study shows highest efficiency of XGBoost and Random Forest algorithms for classification of unmonitored water bodies. The models were compared by their overall accuracy (OA) reaching approximately 93% for binary classification and 72% for comprehensive classification as well as partial class accuracies and the Probability of Misclassification (PoM) parameter. The analyses demonstrates a practical application of AI in assessment of unmonitored water bodies in case of binary classification used for reporting water status objectives of WFD as well as possible usage of full classification for planning and operational uses. OA and PoM are postulated as the best measures of goodness of classification. Further information List of papers in WUT respository

Krystyna Lelicińska-Serafin, Anna Rolewicz-Kalińska, Piotr Manczarski

 

Expanding green areas in cities results in growth in green waste generation. This study presents the findings of an investigation into green waste from selective collection in a large Central European city (Warsaw, Poland), which can be identified as a valuable biomass resource. The research objective was to identify the properties of garden waste from single-family housing to determine valorization opportunities, emphasizing the utilization of GW as a source of energy. The research yielded several findings, including a notable degree of variability in fuel properties, including moisture content (CV = 30%), lower heating value (CV = 14.3%), and ash content (CV = 62.7/56.2%). The moisture content suggests composting, while the fertilizing properties indicate suitability for anaerobic digestion. The instability of the fuel properties, coupled with the elevated levels of chlorine, sulfur, and moisture, constrains the use of garden waste in thermal processes and alternative fuel production. Pyrolysis could be a viable approach for green waste feedstock, offering value-added products depending on the processing conditions and pre-treatment. Nevertheless, implementing a selective collection system is a critical condition for the optimal utilization of bio-waste, facilitating the quality and property control of green and food waste. This is essential for their effective processing, including energy recovery, thereby contributing to the efficient valorization of biomass.

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Katarzyna Nowak-Dzieszko, Maciej Mijakowski and Jarosław Müller

There are many different factors affecting indoor air quality: environmental ones such as temperature, humidity, human activities within the building, smoking, cooking, and cleaning, but also external pollutants such as particulate matter, biological contaminants, and viruses or allergens. This study investigated the indoor air quality (IAQ) of a primary-school classroom in Cracow, Poland, based only on CO2 concentration levels exhaled by occupants. In the 1960s, over a thousand schools were built in Poland using similar technology. Most of them are still in use, and in many cases, modernization works are being carried out to improve their building envelope and the comfort of their use. The analyzed school is one of several hundred similar ones in southern Poland. Therefore, analyzing the possibilities of improving IAQ is an important topic, and the results can be used in the modernization process for many other buildings. Measurements indicated that the CO2 levels significantly exceeded acceptable standards, signaling poor air quality during usage time. This problem was connected mainly with the low efficiency of the natural ventilation system being used in the classroom. It is worth emphasizing that this type of ventilation system is the most commonly used ventilation solution in Polish schools. To address this problem, the classroom environment was simulated using CONTAM software, and the model was validated by comparing the simulated measurement data against the collected measurement data. Next, simulations for the entire heating season in Cracow were conducted, revealing that the IAQ remained consistently poor throughout this period. These findings highlight the persistent problem of inadequate ventilation in the classroom, which can have adverse effects on the health and performance of students and teachers. This article shows the usefulness of CONTAM for modeling not only gravity ventilation but also the window-opening process. The validated CONTAM model will be subsequently utilized to simulate annual IAQ conditions under various ventilation strategies in order to identify the most effective methods for maintaining acceptable IAQ while minimizing energy consumption. In our future analysis, the validated model will be used to test the following systems: demand-controlled ventilation (DCV), exhaust ventilation, and DCV/balanced ventilation with heat recovery.

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Piotr Narowski, Dariusz Heim, Maciej Mijakowski

This article proposes new values and geospatial models of winter and summer external design temperatures for designing buildings’ heating, ventilation, and air-conditioning (HVAC) systems. The climatic design parameters applicable in Poland for the sizing of these installations are approximately 50 years old and do not correspond to Poland’s current climate. New values of climatic design parameters were determined following the methods described in European standards and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Handbook of Fundamentals. The determined climatic design parameters, particularly the winter and summer external design temperatures, were compared with those currently in force by law in Poland. The external air design dry-bulb temperatures presented in the article were developed based on meteorological and climatic data from the years 1991–2020 from two data sources: synoptic data from the Institute of Meteorology and Water Management (IMWM) in Poland and reanalysis models of the ERA5 database of the European Centre for Medium-Range Weather Forecasts (ECMWF). According to ASHRAE, with 99.6% and 0.4% frequency of occurrence, external air design dry-bulb temperatures for winter and summer were used to develop mathematical geospatial models of external design temperatures for the Central Europe area with Poland’s territory in the centre part. Scattered data from 667 meteorological stations were interpolated to 40,000 uniform mesh points using a biharmonic spline interpolation method to develop these models. Linear regression and ANOVA analysis for the ERA5-generated data from 900 checkpoint data items were used to estimate the correctness of these models. Verified models were used to calculate winter and summer external design temperature isolines presented together with colour space representation on Mercator projected maps of Central Europe.

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Tadeusz Skoczkowski, Sławomir Bielecki, Marcin Wołowicz, Lidia Sobczak, Arkadiusz Węglarz, Paweł Grzegorz Gilewski

DSR is crucial for leveraging user flexibility to integrate renewable energy efficiently, also for smaller users like households, and for utilizing surplus energy from prosumers, highlighting its potential. Public perceptions, habits and responsiveness are crucial to its success. A method to determine the initial state of interest in DSR is a survey. This paper presents the results, obtained on the basis of statistical analysis of responses and averaging of scores according to the Likert scale. The survey was conducted among 400 Polish small electricity users. Poland is an exemplary country where external and internal signals can potentially accelerate building a new customer-supported energy sector. The research found low awareness of DSR among individual users, but a strong interest in the concept. It suggested that incentive schemes are preferred over dynamic tariff systems. In general, energy users show rational behaviour regarding specific DSR options, with financial benefits indicated as the primary motivation and social pressure and fulfilling energy policy objectives were deemed least important. This public perception, however, allows for a wider implementation of DSR. Transparent participation rules are crucial. The results research results can inspire policymakers, energy service providers, and aggregators to tailor DSR solutions for diverse end-users.

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Aleksandra Dzido, Justyna Walczak, Honorata Jankowska, Piotr Krawczyk, Gözde Özbayram, Monika Żubrowska-Sudoł

The hydrodynamic disintegration process depends, among others, on operational parameters like rotational speed or introduced energy. The study presents an interdisciplinary approach to the hydrodynamic disintegration parameters impact assessment on the internal processes and disintegration effects on the example of sewage sludge treatment. Three rotational speeds were considered, including fluid properties change at selected disintegration stages. Disintegration effects were measured in the bench tests. Soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) were measured before and after disintegration process. The assessment of the effects of disintegration employed the disintegration degree and the assessment of the course of methane production employed biochemical methane potential (BMP) tests. Fluid properties change during the disintegration stages does not cause a significant change in the flow structure. Due to the mathematical modelling results, at 1500 rpm no cavitation phenomenon was observed. Although, the bench tests results indicates, for the rotational speed 1500 rpm, organic compounds released to the liquid were characterised by higher susceptibility to biological decomposition than those released for 2500 and 3000 rpm (as suggested by the low SCOD/VFA values for 1500 rpm). Obtained results have confirmed, that the main phenomenon responsible for the disintegration effect is mechanical shredding not cavitation.

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Krzysztof Kochanek, Agnieszka Rutkowska, Katarzyna Baran-Gurgul, Iwona Kuptel-Markiewicz, Dorota Mirosław-Świątek, Mateusz Grygoruk

The ice phenomena are an inherent component of rivers in temperate, continental, and polar climate zones. Evident progress in global warming leads to a decrease in snow cover on land and ice phenomena in water bodies, disrupting the stability of the hydrological cycle and aquatic ecosystems. Although common observations indicate the disappearance of ice phenomena in rivers over recent decades, detailed quantitative research is lacking in many regions, especially in the temperate zone. In this paper, ice phenomena were analyzed on the rivers of southern Poland, located in the upland and mountain areas of the country, as no such studies have been conducted so far. The temporal changes in the annual number of days with ice (NDI) phenomena were studied in locations where ice phenomena were observed every year for at least 30 years between 1951 and 2021. Using straightforward but commonly accepted procedures, such as the Mann-Kendall test, statistically significant decreasing trends in the annual NDI were revealed for the majority of gauging stations. The Theil-Sen (TS) slope mean values were -1.66 (ranging from -3.72 to -0.56), -1.41 (from -3.22 to -0.29), and -1.33 (from -2.85 to -0.29) for the datasets representing the periods 1992–2020, 1987–2020, and 1982–2020, respectively. The results for the annual NDI were additionally presented within the context of meteorological characteristics such as annual and winter (Nov-Apr) air temperature, precipitation, and water temperature. Correlation and regression analyses revealed that the main factor triggering the decrease in NDI is the increase in the average winter air temperature. An increase in temperature by 1°C results in a decrease in NDI by up to twenty days. If these negative trends continue, ice phenomena may disappear completely from southern Polish rivers within few decades.

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Natalia Jendrzejewska, Ewa Karwowska

The phenomenon of bacterial resistance to antibiotics, the emission and spread of these bacteria, and the genes that determine antibiotic resistance in the environment are now a major health security concern. This is especially important for anthropopressed surface waters used for recreational purposes. A particular threat is the occurrence of bacteria resistant to frequently applied pharmaceuticals, especially those used to treat persistent and complicated bacterial infections. Hence, a preliminary study of the occurrence of bacteria and genes determining resistance to selected antibiotics, ciprofloxacin and imipenem, was conducted in the bathing waters of the Great Rudnickie Lake. The research showed that the resistance to ciprofloxacin was exhibited by 28% of the total mesophilic bacteria present in water, while the resistance to imipenem was detected in 3.6% of them. It was found that 17–40% of ciprofloxacin-resistant isolates contained the fluoroquinolone-resistance gene qnrS, while the β-lactam-resistance gene blaTEM was found in all the imipenem-resistant strains. The increase in the number of bacteria resistant to the tested antibiotics in the waters of the river outflowing from the lake was observed compared to the inflowing waters, suggesting the potential of the water reservoir as a site for the spreading of drug resistance against tested antibiotics.

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Radosław Czernych, Grzegorz Kozera, Artur Jerzy Badyda, Leszek Bieniaszewski and Paweł Zagożdżon

(1) Haemorrhagic strokes (HS), including intracerebral (ICH) and subarach-noid haemorrhages (SAH), account for approximately 10–15% of strokes worldwide but are associated with worse functional outcomes and higher rates of mortality, and financial burden than ischemic stroke. There is evidence that confirmed poor air quality may increase the incidence of haemor-rhagic strokes. The aim of our study was to evaluate the association between individual ambient air pollutants and the risk of haemorrhagic stroke in an urban environment without high levels of air pollution. (2) Methods: A time-series cross-sectional study design was used. A daily air pollution concentration (Agency of Regional Air Quality Monitoring in the Gdansk Metropolitan Area) and incidence of haemorrhagic strokes (National Health Fund) were obtained and covered the time period from 1 January 2014 to 31 December 2018. A generalised additive model with Poisson regression was used to estimate the associations between 24-h mean concentrations of SO2, NO, NO2, NOx, CO, PM10, PM2.5, and O3 and a daily number of haemorrhagic strokes. (3) Results: The single-day lag model results showed that NO2, NO and NOx exposure was associated with increased risk of ICH (88% events) with RR of 1.059 (95% CI: 1.015–1.105 for lag0), 1.033 (95% CI: 1.007–1.060 for lag0) and 1.031 (95% CI: 1.005–1.056 for lag0), but not for SAH (12% events). Exposure to CO was related to a substantial and statistically significant increase in incidence for 1.031 (95% CI: 1.002–1.061 for lag0) but not for SAH. Higher SO2, PM10, PM2.5, and O3 exposures were not significantly related to both ISC and SAH. (4) Conclusions: In this time-series cross-sectional study, we found strong evidence that supports the hypothesis that transient elevations in ambient NO2, NO and CO are associated with a higher relative risk of intracerebral but not subarachnoid haemorrhage.

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Tomasz Bleschke, Maciej Chaczykowski

A transient pipeline flow model with gas composition tracking is solved for studying the operation of a natural gas pipeline under nonisothermal flow conditions in a hydrogen injection scenario. Two approaches to high-resolution pipeline flow modeling based on the WENO scheme are presented and compared with the implicit finite difference method. The high-resolution models are capable of capturing fast fluid transients and tracking the step changes in the composition of the transported mixture. The implicit method assumes the decoupling of the flow model components in order to enhance calculation efficiency. The validation of the composition tracking results against actual gas transmission pipeline indicates that both models exhibit good prediction performance, with normalized root mean square errors of 0.406% and 1.48%, respectively. Under nonisothermal flow conditions, the prediction response of the reduced model against a high-resolution flow model, with respect to the mass and energy linepack, is at most 3.20%.

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Ewa Karwowska

Bacterial resistance to antibiotics is now an extremely important safety and health issue. Much of the research on this phenomenon focuses on its clinical aspects, while current findings confirm that it is only one of a number of potential sources of bacteria and genes responsible for drug resistance. There are many indications that one of the main contributors to this issue is currently agriculture and that this applies virtually worldwide. Increased awareness of issues of rational use of antibiotics in husbandry practice entails increased interest in phenomena related to the spread of antibiotic resistance in the environment, their specifics, and the scale of the existing threat. This work, based on current research, analyzed selected aspects of the use of antibiotics in animal production, the presence of antibiotic-resistant microorganisms in farm animals and in waste from agricultural production, in particular from animal breeding farms, the determinants of antibiotic resistance in farming practices and the potential threats related to emissions and spread of antibiotic resistance factors in the environment, including the possibility of transfer of resistant bacteria and resistance genes to humans.

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Anna Marszałek, Katarzyna Anna Affek, Monika Załęska-Radziwiłł, Mariusz Dudziak

Rainwater is susceptible to pollutants such as sulphur dioxide, nitrogen oxides, heavy metals, and particles, posing challenges to water quality protection and soil degradation, impacting ecosystems and agriculture. The study focuses on the effectiveness of combined ozonation and photocatalysis in improving physicochemical parameters and reducing toxic substances. Integrated analyses, including ecotoxicological assessments, evaluate the impact of treatment on actual rainwater samples. The results indicate significant reductions in color, heavy metals, and organic pollutants after treatment. Microbiological analyses reveal the inactivation of E. coli, which is crucial for safe water reuse. Ecotoxicity studies show no toxicity to crustaceans, but slight toxicity to algae and bioluminescence bacteria in post-treatment samples. Genotoxicity assessments indicate that there is no detectable DNA damage. Overall, the study highlights the complex nature of rainwater pollution and the efficacy of photocatalytic ozonation in reducing contaminants, underscoring the need for more research to ensure sustainable water resource management.

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Piotr Wichowski, Marek Kalenik, Gabriela Rutkowska, Maciej Malarski, Justyna Czajkowska, Wojciech Franus

The article presents an analysis of the results of research on the composition of fly ash from the thermal processing of sewage sludge [SSA] collected from three incineration plants located in Warsaw, Cracow and Łódź. It determines the leaching values of selected heavy metals from the tested fly ash and ordinary class concrete C20/25 with partial replacement – up to 20% of cement with fly ash. The laboratory tests performed showed that they have a comparable granulometric composition. In contrast, the physico-chemical properties of the tested fly ashes differ from ashes from coal combustion traditionally used in concrete technology. SSA is characterized by an average lower content of silicon, iron, and aluminium oxides with a much higher content of phosphorus oxides. Leaching tests indicate low mobility of heavy metals, meeting Polish regulations regarding the possibility of using SSA in construction for specific applications. At the same time, they do not pose a significant threat to human health or the environment. Construction waste containing SSA may be disposed of in inert waste landfills.

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Andrzej Chmielewski, Marcin Sudlitz, Monika Żubrowska-Sudoł

In present times, with increasing emphasis on circular economies, municipal wastewater treatment plants (WWTPs) are considered resource recovery facilities. The targeted resources are water, biogas, and sludge, organic residuals containing nutrients and elements needed by plants (nitrogen and phosphorus). Sludge is a byproduct that constitutes the largest volume of all other byproducts obtained in wastewater treatment plants. Its processing and disposal are challenging for environmental engineers because of its complexity. Thus, quick development and implementation in industrial practice of sludge valorization and utilization technologies is required, where high nutrient content must be taken into account. Also, the occurrence of a variety of pathogens in sewage sludge is a matter of concern, even in the case of developed countries. The use of untreated sludge or wastewater in agricultural activities poses a serious risk of bacterial and parasitic infection in human beings. To overcome such issues, the application of ionizing radiation processing, especially electron beam (EB), can be considered a promising method. Its effectiveness in pathogen removal has been proven by researchers. Water radiolysis products created during irradiation of water are highly reactive and cause some effects such as DNA damage, 𝑂𝐻  radical production, etc. Additionally, ionizing radiation technologies in sewage sludge treatment enhance the efficiency of the methane fermentation process. Depending on specific needs, different types of ionizing radiation sources can be discussed. Based on the review information and our research results, the basic engineering parameters of hybrid installation have been presented as the conclusion of the report. In this technical solution, a notably effective additional step would be the use of EB irradiation, combined with conventional wastewater treatment, to achieve efficient removal of pollutants.

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August Wrotek, Artur Jerzy Badyda, Teresa Jackowska

N-acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties. The respiratory syncytial virus (RSV) is one of the most important etiological factors of lower respiratory tract infections, and exposure to air pollution appears to be additionally associated with higher RSV incidence and disease severity. We aimed to systematically review the existing literature to determine which molecular mechanisms mediate the effects of NAC in an RSV infection and air pollution, and to identify the knowledge gaps in this field. A search for original studies was carried out in three databases and a calibrated extraction grid was used to extract data on the NAC treatment (dose, timing), the air pollutant type, and the most significant mechanisms. We identified only 28 studies conducted in human cellular models (n = 18), animal models (n = 7), and mixed models (n = 3). NAC treatment improves the barrier function of the epithelium damaged by RSV and air pollution, and reduces the epithelial permeability, protecting against viral entry. NAC may also block RSV-activated phosphorylation of the epidermal growth factor receptor (EGFR), which promotes endocytosis and facilitates cell entry. EGFR also enhances the release of a mucin gene, MUC5AC, which increases mucus viscosity and causes goblet cell metaplasia; the effects are abrogated by NAC. NAC blocks virus release from the infected cells, attenuates the cigarette smoke- induced shift from necrosis to apoptosis, and reverses the block in IFN-γ-induced antiviral gene expression caused by the inhibited Stat1 phosphorylation. Increased synthesis of pro-inflammatory cytokines and chemokines is induced by both RSV and air pollutants and is mediated by the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways that are activated in response to oxidative stress. MCP-1 (monocyte chemoattractant protein-1) and RANTES (regulated upon activation, expressed and secreted by normal T cells) partially mediate airway hyperresponsiveness (AHR), and therapeutic (but not preventive) NAC administration reduces the inflammatory response and has been shown to reduce ozone-induced AHR. Oxidative stress-induced DNA damage and cellular senescence, observed during RSV infection and exposure to air pollution, can be partially reversed by NAC administration, while data on the emphysema formation are disputed. The review identified potential common molecular mechanisms of interest that are affected by NAC and may alleviate both the RSV infection and the effects of air pollution. Data are limited and gaps in knowledge include the optimal timing or dosage of NAC administration, therefore future studies should clarify these uncertainties and verify its practical use.

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Jarosław Zawadzki, Piotr Fabijańczyk, Tadeusz Magiera

Soil contamination is one of the most pressing environmental problems on a global scale. However, assessing the shape and size of an area where pollution occurs, and the spatial variation in the pollution level, is a complex issue. Field magnetometry is a cheap and fast tool for soil pollution assessment. The purpose of the paper is to systematically describe the history, current state, and potential future applications of geostatistical methods in field magnetometry. Materials and methods: The article was written based on over a hundred outstanding scientific papers describing soil research around the world using field magnetometry and geostatistical methods, combined with various secondary variables such as geochemical and diffuse reflectance spectroscopy measurements of soil as well as satellite observations. Results and discussion: Geostatistical methods allow for the optimal use of the magnetometric method in areas with different types of soils such as forests, arable fields, meadows, fallow lands, and urban areas as well as for the determination of spatial variability parameters of magnetic susceptibility. The use of geostatistical methods in field magnetometry also allows for a more accurate determination of other soil and environmental parameters significantly affecting the value of magnetic susceptibility, which must be taken into account when conducting field measurements. Conclusions: Both geostatistics and field magnetometry are considered groundbreaking methods in pedological research but even greater results arise from the simultaneous use of these methods. The synergy effect resulting from the use of geostatistical methods in field magnetometry allowed for the achievement of many significant scientific and practical findings. Especially, the cokriging method plays an increasingly important role in magnetometric research, thanks to the integration of magnetic susceptibility measurements with other types of measurements.

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Omar Ashraf Nimr, Niels Van Putte, Patrick Meire, Mateusz Grygoruk, Goedele Verreydt, Maria Grodzka-Łukaszewska

Diurnal groundwater level fluctuations (DGLF), closely tied to the metabolic rhythm of wetland vegetation, offer insights into direct groundwater consumption. This study is centered on exploring the spatial and temporal patterns of DGLF within the riparian aquifer of the Upper Biebrza region, motivated by the need to understand those sub-daily ecohydrological dynamics at play in this ecosystem, on a process-oriented scale. Through integrated spatiotemporal multivariate analysis, we aim to identify the key potential factors driving variations in these fluctuations across the landscape gradient, as well as, at different time scales. The study employed a comprehensive approach to gather data on groundwater heads and direct groundwater fluxes, utilizing high-temporal-resolution wells within a monitoring network. Meteorological variables from a dedicated station and high-resolution remote sensing maps were also integrated into the dataset. Analysis revealed distinct seasonal patterns and correlations in diurnal groundwater fluctuations, closely correlated with air temperature, solar radiation and subsequently vegetation phenology. Soil moisture content and summer rainfall events also influenced the intensity of these diurnal fluctuations. Dry periods intensified fluctuations, indicating an elevated reliance on groundwater by phreatophytes, while fluctuations decreased after rainfall events, signaling a shift in vegetation’s water source preference to soil moisture. Based on integrated data interpretation, a couple of potential mechanisms, reasonably forming the spatial variation pattern of DGLF, were formulated. Notably, the influence of local hydraulic gradients at transitional forest landscape edges, where higher amplitude fluctuations occurred, compared to lower fluctuations at midpoints. The proximity to the peat-mineral interface influences diurnal fluctuations, with wells closer to the interface showing sustained high-amplitude fluctuations driven by higher rates of recharge. Additionally, the influence of river proximity was explored, revealing dampened fluctuations in wells closer to the river due to rapidly changing hydraulic gradients. Further systematic experimentation, including numerical and data-driven modeling, is needed to validate these hypotheses. The study findings provide perspectives into (DGLF) patterns and distributions, enabling more accurate groundwater evapotranspiration (ETg) estimation and opening new avenues for considering ecohydrological feedback regarding carbon–water interaction, in relation to the daily-scale water table position.

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Tesfaye B. Senbeta, Jarosław Napiórkowski, Emilia Karamuz, Krzysztof Kochanek, Yali E. Woyessa

Study region: The Pilica River watershed, located in central Poland, is the largest left tributary of the Vistula River basin. Study focus: The study aims to assess the impact of human activities on drought dynamics by considering the specific role of the Sulej´ow Reservoir. Identifying factors contributing to drought development is essential for decision-makers to implement appropriate management measures. The temporal overlap method is used to distinguish between climate and human-driven droughts. The changes in drought propagation are assessed using the time shift method at various accu- mulation time scales. To assess the spatial distribution of drought, we applied the Soil and Water Assessment Tool (SWAT) model to simulate soil moisture and streamflow response at a spatial scale. New hydrological insights for the region: The findings highlight that about 75% of meteorological droughts lead to soil moisture droughts, and about 70% result in hydrological droughts. The results show the contribution of human activities to soil moisture drought (~25%) and hydro- logical drought (~10%), indicating that not all droughts are driven by meteorological factors alone. The key finding suggests a shorter and longer time scale of around 3 and 12 months for soil moisture drought and hydrological drought propagation analysis, respectively. Moreover, the decrease in the duration and severity of drought during 2005–2019 compared to 1997–2004 suggests that the magnitude of the reservoir impact depends on its purpose and operational strategies.

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Michał Kubrak

The aim of this research was to experimentally analyse the possibility of using a rubber hose placed inside a pipeline to mitigate the water hammer phenomenon. The experiments were conducted using a steel pipeline with an inner diameter of 53 mm and an EPDM rubber hose with a diameter of 6 mm. Hydraulic transients were induced by a rapid closure of the valve located at the downstream end of the pipeline system. In order to analyse the influence of steady-state flow conditions on the maximum pressure increase, measurements were carried out for different values of initial pressure and discharge. The experimental results indicate that placing a rubber hose inside a pipeline can substantially attenuate valve-induced pressure oscillations. It was observed that the initial pressure has a significant influence on the capacity of the rubber hose to dampen the water hammer phenomenon. Comparative numerical calculations were performed using the Brunone–Vitkovský instant acceleration-based model of unsteady friction. It was demonstrated that this approach does not allow satisfactory reproduction of the observed pressure oscillations due to the viscoelastic properties of the EPDM hose used in the tests.

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Artur Jerzy Badyda, Mariusz Rogulski

This article presents the impact of vehicle traffic intensity and the closure of access roads for wheeled vehicles to selected schools in Warsaw at selected hours of the day on changes in air quality. This study focused primarily on analyses related to the pollutant typical of road traffic, i.e., nitrogen dioxide, but also took into account PM10 and PM2.5 concentrations, which are some of the key factors determining the quality of atmospheric air, the sustainability of human beings, and sustainable development. Some kinds of relationships were found between vehicle traffic intensity and air pollutant concentrations, in particular—nitrogen dioxide. Analyses of the pollutant concentrations in the periods before and after the introduction of restrictions on vehicle traffic on working days indicate that, in the case of two of the schools during the morning traffic rush hours, significantly lower NO2 concentrations were observed in the period after the introduction of road traffic restrictions, compared with the period before they were introduced. NO2 concentrations during the morning peak hours (on working days) after introducing restrictions were more than 30% lower than the concentrations recorded during the same hours in the period before introducing restrictions.

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Michał Kubrak

Hydraulic transient analysis through numerical simulations is a widely used tool for predicting and mitigating potential severe pressure oscillations due to abrupt changes in flow velocity. In practice, water hammer events typically are induced by valve operations used to control the flow rate. One of the methods to enhance the throttling capabilities of a gate valve is to install a V-shaped notch (V-port) in its opening. This provides a more linear relationship between the position of the gate and the flow rate discharging through the valve. The exact range of the flow control is determined by the V-port opening angle. Because valve-induced pressure oscillations depend on the valve characteristics, in order to accurately simulate the transient event, the specific valve closing function is required. The primary objective of this paper was to develop valve closing functions of V-port gates for all possible opening angles. Two cases were considered: the linear closure of a knife (rectangular) and a circular gate fitted with a V-port. For this purpose, the analytical formulas for calculating the relative opening area of V-shaped gate valves were derived. On this basis, valve closing functions, in the form of a power function with two variables, were developed. To analyze the influence of the V-port angle on a simulated transient event, a case study with a simple reservoir–pipeline–valve system was investigated. One-dimensional unsteady flow equations were solved using the method of characteristics. The numerical calculations conducted indicate that installing a V-notch port can result in a smoother reduction of the flow rate as the gate closes, which may dampen both maximum and minimum pressure peaks and attenuate valve-induced pressure head oscillations. The developed valve closing functions offer practical utility for practitioners engaged in hydraulic system design and operation, providing a tool for predicting hammer events induced by valve gates fitted with V-ports.

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Kamil Świętochowski, Dariusz Andraka, Marek Kalenik, Joanna Gwoździej-Mazur

Taking care of water resources and minimizing water losses in water supply networks requires a broad approach to identifying and neutralizing operational problems. The correct selection of water meters to minimize apparent losses requires knowledge of the characteristic flows that may occur in the facility to which water is supplied. The research aimed to develop tools in the form of mathematical models and water consumption curves along with hourly water consumption coefficients to facilitate the process of selecting water meters for engineers and creating computer models of water supply systems. The research involved monitoring the flow of 76 single-family and multi-family buildings in four towns in Poland, followed by data analysis and development of tools supporting the selection of water meters and the construction of computer models of water distribution networks. High correlation coefficients of the studied variables indicate the results’ usefulness. Four models were developed to determine the maximum flow values in multi-family buildings (three models) and single-family buildings (one model) in the range of water meter diameters DN15-DN40. Characteristics of the average hourly peak coefficient (HPC) values were also developed, along with the range of changes in HPC values for single-family and multi-family buildings.

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Adam Lipski, Maciej Witek, Mechri Abdelghani, Piotr Swacha

The aim of this work is an experimental evaluation of a specific heat capacity as a function of plastic strain for thermo-mechanically rolled pipe material, with application of an infrared thermographic camera. The tensile load tests of samples prepared of L485ME (X70M) steel grade were performed with the use of a strength machine. Based on other known material thermophysical properties, the determination of heat source parameters was conducted with the use of an infrared thermography and with an optimization task solution. A linear regression equation describing the specific heat capacity as a function of plastic percentage elongation for L485ME steel grade was determined. The experimental results of the present study showed a linear increase in the specific heat capacity in the range of the analyzed tensile deformation up to 16%. The presented methodology is suitable for assessment of the material specific heat capacity as a function of strain up to the occurrence of the sample narrowing in a direction perpendicular to the tensile force.

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Thanh-Nhan-Duc Tran, Son Kim Do, Binh Quang Nguyen, Vinh Ngoc Tran, Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Venkataraman Lakshmi

Quantifying the intensity and frequency of climatic extremes under the impacts of climate change is crucial for effective water resource management. In this study, we utilize the soil and water assessment tool hydrological model, robust indices, e.g., standardized precipitation index and standardized streamflow index as well as the interquartile range method for a comprehensive analysis of the river flow response to future climate scenarios towards 2090. Four general circulation models under two shared socioeconomic pathways have been used, including BCC-CSM2-MR, CanESM5, MIROC6, and MRI-ESM2-0. We aim to reveal the future impacts of extreme events and their potential consequences for local livelihoods and human well-being in the Srepok River basin—a major tributary of the Mekong River basin in Southeast Asia. Our findings include the following: 1) a significant discrepancy between extreme events found with more flood events projected toward 2090; 2) a shift in precipitation patterns with an increase in intensity is observed; and 3) a correlation between climatic extremes and regional characteristics has been identified. This work provides valuable insights into the anticipated changes in climatic extremes under the impacts of climate change and serves as the scientific basis for stakeholders and decision-makers to develop adaptative strategies and sustainable plans to enhance the region’s resilience.

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Olga Zając, Magdalena Zielinska, Monika Żubrowska-Sudoł

The study aimed to investigate how hybrid technology, combined with various intermittent aeration (IA) strategies, contributes to reducing the energy costs of wastewater treatment while simultaneously ensuring a high treatment efficiency. Even with IA subphases lasting half as long as those without aeration, and oxygen levels reduced from 3.5 to 1.5 mg O2/L, pollutants removal efficiency remains robust, allowing for a 1.41-fold reduction in energy consumption (EO). Hybrid technology led to a 1.34–fold decrease in EO, along with improved denitrification efficiency from 74.05 ± 4.71 to 81.87 ± 2.43 % and enhanced biological phosphorus removal from 35.03 ± 4.25 to 87.32 ± 3.64 %. The high nitrification efficiency may have been attributed to the abundance of Pseudomonas, Acinetobacter, and Rhodococcus, which outcompeted the genera of autotrophic nitrifying bacteria, suggesting that the hybrid system is favorable for the growth of heterotrophic nitrifiers.

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Arkadiusz Stachurski, Frank Delgorge, Adam Muszyński

This paper presents experiences and challenges related to the implementation and successful 3-year operation of a full-scale station for water reuse from wastewater in one of the largest poultry slaughterhouses in Europe. Solved problems for implementing deammonification, as well as automatic coagulant dosing for wastewater pre-treatment, improvement of activated sludge separation, and digestate management, are presented and discussed. Two major limitations of stable water reclamation were a limit of 30 mg N/L in the effluent to the river and the passing of cationic flocculants and natural polymers formed by activated sludge microorganisms to the ultrafiltration units. The limit of 30 mg N/L was achieved by implementing i) a unique deammonification system to treat leachate from the anaerobic digester, ii) automatic coagulant dosing to mitigate high nitrogen peaks and balance organic compounds between biogas production and efficient denitrification. Flocculants and polymers passing to the ultrafiltration units and causing a sharp drop in water recovery were eliminated by stabilizing the zeta potential of the sludge, adding an antiscalant before the ultrafiltration, and automatic control of wastewater coagulation at primary treatment, responding to COD peaks. With improvements described in the article, the water reuse system provides a stable supply of 4000 m3/d of high-quality water, resulting in over 4 million m3 of water reclaimed since 2020.

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Mirosław Szyłak-Szydłowski, Andrzej Kulig

The aim of the research is to assess changes in odour concentration in the ventilated air of
a production hall, using different types of biofilter fillings and different types of membranes. Deodorisation was carried out using a mobile combined biofilter at a plant producing lard and liquid oils. Ventilated air from the hall contained organic and inorganic pollutants. Two types
of fillings were used for technological tests: stumpwood chips mixed with pine bark and a mix of stumpwood chips with pine bark and green waste compost. Two types of membranes were also used, differing in thickness, permeability, and water resistance. The subjects of the research were the air supplied to the filter, lifted directly from the bed, and the air above the membranes. The deodorisation efficiency—the percentage reduction in the odour concentration value as a result of air flow through the bed and membranes—was calculated. The filtration methods used allowed the selection of the most advantageous technological variant from the point of view of deodorisation effectiveness: a mix of stumpwood chips with pine bark and the Pro Eko Tex UV membrane. It has a total odour reduction efficiency of 99.3–99.9% and has been added to full-scale implementation works.

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Olga Zając, Monika Żubrowska-Sudoł, Martyna Godzieba, Sławomir Ciesielski

A lab-scale pure moving bed sequencing batch biofilm reactor (MBSBBR) was employed to investigate changes in nitrification kinetics and microbial diversity. The MBSBBR operated under different aeration strategies (defined by the ratio of the duration of the subphases with (t1) and without (t2) aeration (R = t2/t1)) − continuous (R = 0) and intermittent (with constant time of non-aerated subphases (t2 = 10 min) and variable duration of subphases with aeration (t1 = 40 min–R = 1/4, t1 = 30 min–R = 1/3, t1 = 20 min–R = 1/2) and dissolved oxygen (DO) concentrations (6 mg/L; 3.5 mg/L). Moreover, the reactor’s organic (OLR) and nitrogen (NLR) loading rates were changed in the following ranges: OLR—537–402 gCOD/m3·d, NLR—64–48 gN/m3·d. The obtained results showed that, irrespective of changes introduced in particular series, a highly effective nitrification process (93.36 ± 2.13%) was achieved. The activity of bacteria capable of oxidizing ammonia nitrogen changed differently from that of bacteria capable of oxidizing nitrites (NOB). An increase in R was the primary factor changing the activity of ammonia-oxidizing microorganisms. NOB activity was affected only by the reduction of OLR and NLR. NOB were the predominant bacterial group, consistent with the kinetics studies. A DO decrease caused an increase in the abundance of AOB, NOB, and Comammox bacteria. Comammox bacteria were the most abundant at R = 1/2 and DO = 3.5 mg/L.

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T. Owczarek, Mariusz Rogulski, P.O. Czechowski, Artur Jerzy Badyda, E. Czermański

The aim of the study was to build a corrective model that can be used in the analysed devices and to assess the impact of such a model on the values of the measured concentrations. The novelty of this study is the test of equivalence with the equivalent reference method for hourly data. The study used hourly data of PM10 concentrations measured in a chosen city in Poland. Data was collected from two PM10 sensors and a reference device placed in close proximity. In addition, air temperature, humidity and wind speed were also measured. Among the tested models, a linear model was selected that used primary measurements of PM10, temperature, air velocity, and humidity as the most accurate approximation of the actual PM10 concentration level. The results of the analysis showed that it is possible to build mathematical models that effectively convert PM10 concentration data from tested low-cost electronic measuring devices to concentrations obtained by the reference method.

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Weronika Borowska, Monika Żubrowska-Sudoł, Nina Doskocz

Initiating the partial nitritation and anammox (PN/A) process without inoculation poses a significant challenge. Thus, there is a notable amount of interest in devising a straightforward strategy for the start-up of PN/A. This study demonstrates the feasibility of achieving the rapid start-up of a one-stage PN/A process within a moving-bed sequencing batch biofilm reactor (MBSBBR) by reducing the oxygen concentrations: 3.0 mg O2/L (Stage I), 2.0 mg O2/L (Stage II), and 1.0 mg O2/L (Stage III). The anammox activity was observed 15 days after a gradual decrease in the oxygen concentration and confirmed using a specific anammox activity test (5.9 mg N/gVSS·h). During Stage III, the average total inorganic nitrogen (TIN) removal efficiency was 60.6%. The relative abundance of planctomycetes, a typical phylum representing anammox microorganisms, increased almost three times from Stage I (2.8%) to Stage III (7.1%). These results demonstrate the potential of a decrease in oxygen concentration for the fast start-up of the one-stage partial nitritation and anammox process without inoculation. The implementation of the studied DO strategy has practical implications for wastewater treatment plant operators, particularly in the start-up of the PN/A processes. Additionally, batch assays allow for the rapid assessment of treatment plant performance, providing real-time insights into its functionality and, thereby, optimizing wastewater treatment practices.

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Paweł Malinowski, Wojciech Dąbrowski, Beata Karolinczak

The filling of constructed wetlands (CWs) affects the efficiency of sewage treatment and proper operation. Mineral aggregates are most often used as filling materials. Significant environmental burdens from mineral mining operations justify the search for waste fill. This study aimed to determine the possibility of increasing the efficiency of CW by using a Certyd aggregate as a new filling. Certyd is produced in the sintering process of coal ash, a waste from combined heat and power (CHP) plant operation. Comprehensive two-year studies were conducted using two real-scale subsurface vertical flow (SS VF) CWs supplied with domestic sewage. One bed was filled with a Certyd and the other was filled with appropriate fractions of a mineral aggregate. Both beds worked in parallel, and to compare their effectiveness, account seasonality was taken into account. The SS-VF Certyd-filled bed achieved an average efficiency of 88.0% for biological oxygen demand (BOD5), 80.2% for chemical oxygen demand (COD), 80.4% for suspended solids (SSs), 80.2 for ammonia nitrogen (N-NH4), 72.2% for total nitrogen (TN), and 55.3% for total phosphorus (TP), while the gravel-filled bed achieved 84.5%, 77.0%, 86.9%, 74.2%, 69.4%, and 57.8% for the whole research period, respectively. A higher effect of the removed unit load was achieved in the bed filled with Certyd (36.2 g BOD5 m−2 d−1, 50.0 g COD m−2 d−1, 5.88 g SS m−2 d−1, 7.1 g TN m−2 d−1, 7.9 g N-NH4 m−2 d−1, 0.79 g TP m−2 d−1) compared to the gravel-filled bed (34.7 g BOD5 m−2 d−1, 47.0 g COD, 6.35 g SS m−2 d−1, 6.9 g TN m−2 d−1, 7.3 g m−2 d−1 N-NH4, 0.83 g TP m−2 d−1).

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Jerzy Trzciński, Emilia Wójcik, Kamil Kiełbasiński, Paweł Łukaszewski, Małgorzata Zaremba, Łukasz Dominik Kaczmarek, Robert Dziedziczak, Jakub Kotowski, Ana Konestra, Fabian Welc, Tomasz Wejrzanowski, Jakub Jaroszewicz

This article presents the results of petrophysical analyses of limestones and sandstones used for the construction of the wall structures of a Roman rural settlement located in Podšilo Bay on Rab Island (Croatia). An on-site analysis of the walls indicated the use of different lithotypes, which is an uncommon case in the area. So far, no petrophysical properties of the applied materials have been tested, and their provenance has not been specified. The aim of this research was to determine their usability as construction materials in an attempt to determine the possible reasons behind the usage of multiple lithotypes and their suitability as building materials. The following procedure was used to address these issues: (1) determination of the petrographic characteristics of the rocks, (2) performance of tests to characterise the mechanical properties in a complex stress state of uniaxial tension followed by uniaxial and triaxial compression, and, finally, (3) determination of the internal structure of the rocks using methods based on X-ray imaging. Multi-proxy characteristics of the materials including numerous observations and methods were performed: optical microscopy used to characterise rock petrography and mineralogy, scanning electron microscopy (SEM) coupled with EDS, as well as grinding tests; furthermore, mechanical properties were determined on cylindrical samples in accordance with European standards. X-ray microtomography using the XμCT method enabled microscopic observations and determination of the orientation of discontinuities and the rock structure. The performed analyses allowed us to distinguish three lithological types of sandstone and two types of limestone among the examined stone blocks. Stone blocks of fine- and medium-grained sandstone with carbonate binders, as well as sparitic limestone and mudstone with calcite veins, were used to build the studied structures. The analysed blocks showed traces of partial edge processing. Despite the defects in the material structure identified using XμCT, all the types of rock were characterised by high or very high strength. High values of longitudinal wave velocity confirmed the good quality of the material. These results contribute to a better understanding of the construction process and the related technological choices, and they provide the first dataset which can be used for the reconstruction of the building’s original appearance in the future.

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Khadija Shaheen, Apoorva Chawla, Ferdinand Uilhoorn, Pierluigi Salvo Rossi

A significant quantity of sensors distributed throughout the natural gas pipeline is susceptible to errors. Timely diagnosis of sensor faults in such scenarios holds great significance in averting catastrophic failures. This article proposes a novel approach termed model-based multisensor fault detection, isolation, and accommodation (MM-SFDIA) technique to mitigate multiple sensor faults occurring simultaneously in large-scale distributed systems. The proposed approach leverages a distributed filtering framework, employing multiple local ensemble Kalman filters (EnKFs). Each individual local filter generates a distinct local state estimation using a distinct set of sensor measurements. By analyzing the differences among these local state estimates, a strategy based on state consistency, the faulty sensors are identified. Furthermore, an adaptive thresholding technique is devised to ensure resilient fault detection and identification. Compared with the existing state-of-the-art techniques, the proposed approach offers a lower computational burden and is applicable to high-dimensional nonlinear systems with numerous sensor faults. Moreover, the results affirm the effectiveness of the proposed architecture, demonstrating a high accuracy and low execution time in detecting and isolating multiple sensor faults.

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This study presents the potential impacts of climate change in 49 Polish cities by analyzing seven climate indicators. The analysis was carried out for the following three horizons: the current climate conditions (an average period spanning 2006 to 2015), near-future conditions (an average period spanning 2026 to 2035), and future conditions (an average period spanning 2046 to 2055). Climate indices were computed with bias-corrected EURO-CORDEX model ensembles from two Representative Concentration Pathway scenarios, RCP4.5 and RCP8.5. The systematic error was reduced using the quantile mapping method with a non-parametric approach of robust empirical quantiles (RQUANT). Data were used as references in the period of current climate conditions, and those required for bias correction consisted of historical ground-based observations provided by the Institute of Meteorology and Water Management. The analysis encompassed various key climate indices, including the annual average temperature, the count of hot days, cold days, and frost days, the cumulative annual precipitation, the frequency of days with precipitation, and instances of extreme precipitation (defined as the days with precipitation exceeding 10 mm/day). These findings reveal a noteworthy rise in the average annual temperature of approximately 1 °C and an uptick in the number of hot days by 3.7 days. Conversely, a decline in the number of cold days by approximately 19 days and frost days by 8 days was observed. Additionally, there was an augmentation in the annual precipitation sum, reaching up to 80 mm in RCP 8.5, accompanied by an increase in the number of days with precipitation (up by 3.3 days) and days with extreme precipitation (up by 2 days).

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Maria T. Markiewicz

This study concerned the integration of gas pipeline safety issue into the LUP (Land Use Planning) and SEA (Strategic Environmental Assessment) processes in Poland. It focused on the early stage of natural gas transmission pipeline localisation, i.e. the preparation of land use development plans (the plans) and accompanying SEA documents. It aimed to analyse a set of selected plans and SEA documents taking into account risks to people and the environment resulting from accidents on gas pipelines. The results of the analysis showed that although the Polish legislation defining the content of these documents does not explicitly refer to these risks, they are included, but to a limited extent, in the documents examined. It is proposed to modify the EU and Polish legislation for the control of major accident hazards on gas pipelines.
In particular, in addition to the generic-distances approach currently used in Poland for maintaining the separation distances between the gas pipeline and other buildings it is suggested to introduce a risk-based approach to support LUP decisions near gas pipelines in Poland.

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Piotr Manczarski, Anna Rolewicz-Kalińska, Krystyna Lelicińska-Serafin

Food waste management is one of the key challenges of the circular economy and climate transition policies. The proper collection of food waste is the starting point for its further value recovery. Most of the quantitative and qualitative data used to measure the scale of food waste in households and its collection are based on statistical data, diaries, and questionnaires. There is a visible gap in research in terms of the use of direct research methods. This paper presents the results of a quantitative research study on household food waste accumulation and collection in Warsaw from two sources: single-family and multi-family households. The results of the study indicate that in Warsaw households, one can expect generation at the level of 33.4 kg·capita−1·year−1 of avoidable food waste and 38.2 kg·capita−1·year−1 of unavoidable food waste. The average food waste collection rate from households in Warsaw was determined to be at a level of 19.6 kg·capita−1·year−1. In multi-family buildings, which are dominant in Warsaw, this rate is half as pronounced (17.3 kg·capita−1·year−1) compared to single-family buildings (36.2 kg·capita−1·year−1). The average food waste collection efficiency rate from Warsaw households was at a level of 32%. Avoidable food waste accounted for 47% of all food waste generated. The study indicates a growing need to develop policy tools to support the separate collection and prevention of food waste.

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Olga Zając, Monika Żubrowska-Sudoł, Martyna Godzieba, Sławomir Ciesielski

This study investigated how mainstream-sidestream switching affected the activity and abundance of canonical nitrifiers and Comammox bacteria. The experiment started in a mainstream hybrid reactor for C, N, and P removal with biomass in the form of activated sludge and biofilm. A highly effective nitrification sidestream reactor with pure moving bed technology was then obtained through gradual reduction of the reactor’s organic loading rate (OLR), increase in the temperature (20–30 °C), and increase in the reactor’s nitrogen loading rate (NLR). qPCR and kinetic batch test results suggest that Comammox bacteria could play an important role in nitrification in both the mainstream hybrid reactor and sidestream biofilm reactor, dominating even the canonical AOB. Biofilm provided a better environment for Comammox bacteria development, except when the system was transformed into a hybrid nitrifying reactor. In that case, the occurrence of Comammox bacteria in activated sludge was greater. Simultaneously with reduction of OLR an increase in ammonia oxidation rate was reported in both activated sludge and biofilm. An increase in NLR had a greater effect on the activity of NOB.

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Ferdinand Uilhoorn

In data assimilation, the description of the model error uncertainty is of the utmost importance because, when incorrectly defined, it may lead to information loss about the real state of the system. In this work, we proposed a novel approach that finds the optimal distribution for describing the model error uncertainty within a particle filtering framework. The method was applied to nonlinear waves in compressible flows. We investigated the influence of observation noise statistics, resolution of the numerical model, smoothness of the solutions, and sensor location. The results showed that in almost all situations the Pearson Type I is preferred, but with different curve-shape characteristics, namely, skewed, nearly symmetric, ∩-, ∪-, and J-shaped. The distributions became, in most cases, ∪-shaped when the sensors were located near the discontinuities.

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Artur Mielcarek, Kamil Łukasz Bryszewski, Joanna Rodziewicz, Marian Kwietniewski, Wojciech Janczukowicz, Karolina Kłobukowska, Joanna Struk-Sokołowska

The management of wastewater from soilless tomato cultivation poses a technological and economic challenge. Given the above, the aim of this study was to determine the treatment efficiency of wastewater from soilless tomato cultivation in a bio-electrochemical reactor under conditions of direct electric current flow. The treatment efficiency was tested in three time variants of wastewater exposure to the electric current: V1—24 h exposure phase; V2—12 h exposure phase/12 h no exposure phase; and V3—12 h no exposure phase/12 h exposure phase. Experiments were conducted with two organic substrates, sodium acetate and acetic acid, at the C/N ratio of 1.25, with a direct current intensity of 1.25 A·m−2 and hydraulic retention time of 24 h. The study results show the feasibility of achieving a satisfactory technological effect in a bio-electrochemical reactor without the need for electric current flow throughout the 24 h treatment cycle. From the energy consumption and technological standpoints, the most viable approach, ensuring 90.4 ± 1.6% and 94.9 ± 0.7% efficiencies of nitrogen and phosphorus removal, respectively, turned out to be feeding the reactor with sodium acetate and wastewater exposure to the electric current flow only during the first 12 h of the treatment cycle. The scope of the conducted research justifies its continuation in order to determine the optimal time for supplying electricity to the bio-electrochemical reactor and the impact of the C/N value on the nitrogen and COD effluent concentrations.

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Justyna Zamorska, Ewa Karwowska, Wioletta Przystaś

A very important role in determining the quality of water is the assessment of its microbiological quality. Water quality control, which could pose a direct threat to human health and life, is performed in the case of water produced at water treatment plants, tap water, or water in swimming pools. However, these traditional methods used to assess its quality are laborious and time-consuming. In emergency and incidental situations, in the era of terrorist threats, the need for quick, reliable, and reproducible microbiological determinations seems to be essential. In this study, an attempt was made to compare various methods of assessing the microbiological quality of water. The assessment was carried out for water with different microbiological characteristics: surface water, rainwater, groundwater, and water supply. The evaluation was carried out using traditional culture methods and high-speed methods: flow cytometry and luminometry. The analysis of microbiological parameters was the basis for the statistical analysis. The conducted microbiological analysis of various types of water, along with their statistical evaluation, showed different dependencies for each of the analyzed waters.

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Thanh-Nhan-Duc Tran, Binh Quang Nguyen, Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Venkataraman Lakshmi

Forecasting streamflow is important for managing future water resources and environmental needs under the impacts of climate change. Moreover, quantifying the combined effects of future climate variations and human-made infrastructures, e.g., dams and reservoirs, poses a significant challenge. In this study, we used the Soil and Water Assessment Tool (SWAT) for a case study in the Srepok River Basin—a tributary of the Mekong River Basin. Here, we aim to reveal the impacts of various climate change scenarios and the effects of reservoir operations in this region. Our findings indicate that 1) the projected annual streamflow is anticipated to increase by a minimum of 9.2% (2046–2065) and could peak at an increase of 14.9% (2080–2099) under the highest greenhouse gas emissions, 2) Srepok 4, Srepok 3, and Buon Kuop demonstrate a higher capability for mitigating flood peaks and managing seasonal flow in the downstream floodplain, whereas Buon Tua Srah shows the least performance, and 3) reservoirs operated with annual regulation have more pronounced impacts than those regulated on a daily schedule. Our work provides i) a scientific foundation for regional stakeholders and decision-makers to develop sustainable strategies that address the combined effects of reservoir operation and future climate, and ii) it supports national authorities and officials in resolving conflicts related to transboundary rivers within the Mekong River Basin.

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Justyna Stańczyk, Krzysztof Pałczyński, Paulina Dzimińska, Damian Ledziński, Tomasz Andrysiak, Paweł Licznar

Developments in data mining techniques have significantly influenced the progress of Intelligent Water Systems (IWSs). Learning about the hydraulic conditions enables the development of increasingly reliable predictive models of water consumption. The non-stationary, non-linear, and inherent stochasticity of water consumption data at the level of a single water meter means that the characteristics of its determinism remain impossible to observe and their burden of randomness creates interpretive difficulties. A deterministic model of water consumption was developed based on data from high temporal resolution water meters. Seven machine learning algorithms were used and compared to build predictive models. In addition, an attempt was made to estimate how many water meters data are needed for the model to bear the hallmarks of determinism. The most accurate model was obtained using Support Vector Regression (8.9%) and the determinism of the model was achieved using time series from eleven water meters of multi-family buildings.

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Małgorzata Wojtkowska, Jan Bogacki

Bottom sediments were tested in order to determine the possibility of immobilization of heavy met- als with the use of natural sorbents, chitosan and bentonite. The content of Cu, Zn, Cd and Pb was determined, and speciation analysis was performed using the sequential Tessier methodology. The use of sorbents clearly changes the speciation forms of all tested heavy metals by comparing the distribution of metals before and after the application of the sorbent for both chitosan and benton- ite. The addition of natural sorbents affect the immobilization of metals deposited in bottom sedi- ments of water reservoirs. However, the behavior of metals in the presence of sorbents results from their properties and the nature of the sorbent. The positive effect of sorbents on metal immobili- zation was not observed in every case. The addition of the tested sorbents in the case of cadmium caused an increase in the content of Cd in the mobile fractions, for Zn, Pb and Cu, stronger binding of metals was found in the stable fractions IV and V. Chitosan stabilized metals more strongly than bentonite, which moved Zn, Pb and Cu to the first mobile fraction.

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Karol Wojciech Wojtkowski, Małgorzata Wojtkowska, Magdalena Długosz-Lisiecka, Agata Walczak

The aim of the research in the Poleski National Park was to determine the concentration of radionuclides and heavy metals in the soil and to evaluate the absorbed dose and the average annual effective dose as a result of external exposure to ground-based radiation sources. The spread of anthropogenic radionuclide concentration in the Poleski National Park was the highest. This is a first-of-its-kind study in Poland. The annual effective dose calculated for the Poleski National Park was over three times higher than the average worldwide value. Soil samples were subjected to mineralization using a TITAN MPS with a rotor. Subsequently, the metals in the obtained solutions were determined using the atomic absorption spectrometry method with flame atomization (AAS FM). The content of copper Cu, nickel Ni, lead Pb, cadmium Cd, and chromium Cr did exceed the average content neither in Europe nor around the world. The soils of the Poleski National Park are characterized by pollution with the tested heavy metals, especially cadmium Cd.

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Beata Karolinczak, Justyna Walczak, Magdalena Bogacka, Monika Żubrowska-Sudoł

Wastewater treatment plants (WWTPs) aim to increase energy independence by intensifying biogas production. The study involved Life Cycle Assessment (LCA) comparing sewage sludge (SS) anaerobic co-digestion (AcD) with the organic fraction of municipal solid waste (OFMSW) at WWTP against SS anaerobic mono-digestion (AD). The LCA was based on the authors’ research showing that methane production related to wet mass in AcD was higher than in AD by 86.4, 225.8, and 354.3 % for SS:OFMSW mixing ratios of 75:25, 50:50, and 25:75, respectively. The LCA was conducted for 1 kWh of biogas energy produced at a WWTP and included two subsystems: energy production (AD/AcD and CHP) and associated digestate management (drying, incineration with energy reuse, residual landfilling). CML-IA baseline 2013 and Recipe 2016 Midpoint (H) LCIA methodologies indicated the environmental impacts on abiotic depletion – fossil fuels (fossil resource scarcity), global warming, human toxicity (non-carcinogenic), freshwater, and marine aquatic ecotoxicity. AD of SS in all categories was characterized by the highest impact. The impact decreased with an increase in the OFMSW rate. Both methodologies showed a significant impact of AD and AcD on global warming, which indicated the need for the determination of the carbon footprint (CF) of 1kWh biogas energy production (gCO2 kWh−1) at WWTP, using IPCC 2021 GWP100 (incl. CO2 uptake). The CF was the highest for biogas energy production in SS AD (1509 gCO2 kWh−1) and it decreased with the increase of OFMSW content in AcD (872–481 gCO2 kWh−1). This was also observed for the management of associated digestate. CF changed from 1508 gCO2 kWh−1 for SS AD to 396 gCO2 kWh−1 for SS: OFMSW mixing ratio of 25: 75 in AcD. The environmental burdens associated with biogas energy production and digestate management were equally significant. Finally, the formula for economic and ecological comparison of SS AD and AcD with OFMSW was proposed.

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Łukasz Szarek, Łukasz Krysiak, Zbigniew Kledyński, Agnieszka Machowska, Paweł Falaciński

Cut-off walls built using self-hardening slurries are an important tool for modern engineering pursuing Sustainable Development Goals. Much like cement concrete, this material is affected by the challenges posed by the increasing human pressure on the environment, although it is used significantly less widely than concrete; for this reason, relatively little comprehensive literature data is available describing the interaction of self-hardening slurries with the environment. This article provides a review that complements the current state of knowledge on self-hardening slurries in this area, with a particular focus on the durability of the material and its pollutant immobilization capabilities. To provide context, the material’s operating conditions, properties and components are briefly characterized. The resistance of self-hardening slurries to environmental aggression is described extensively, as it is a key factor in ensuring the durability of the material. A sample analysis of the material’s carbon footprint in several representative composition variants is presented. The subject of pollutant immobilization by self-hardening slurries is outlined. Lines of further research are proposed to fill gaps in the available knowledge.

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Alicja Knap-Bałdyga, Monika Żubrowska-Sudoł

Considerable changes have been observed in surface waters’ quality in recent years. They include an increase in dissolved organic carbon (DOC) concentrations, as well as a shift of natural organic matter (NOM) composition in favor of low molecular weight (LMW), and they are expected to occur on a wider scale in the future. Those predictions are particularly worrying given the importance of surface water as the main potable water source for numerous communities across the globe. Conventional methods of surface water treatment for drinking purposes mostly focus on the process of coagulation. The progressing changes in the quality of surface waters, however, render the conventional treatment via coagulation inefficient. The issue of the presence of natural organic matter in drinking water sources, its anticipated changes, and the related treatment problems are all complex and pressing matters that need addressing. This paper aims to provide a critical review of recent findings regarding NOM removal via coagulation in reference to the current NOM-related issues and their potential solutions. The paper discusses the application of different types of coagulants, and their respective advantages and disadvantages. Coagulation-integrated processes including adsorption, membrane filtration, biological processes, and oxidation are also addressed. Lastly, insights on the future approach to the discussed issues and conclusions are presented.

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Klara Ramm, Małgorzata Sielska

The practical implementation of solutions compatible with the circular economy is crucial in Europe. The authors present a case study for a small Polish agglomeration. The local wastewater treatment plant operator took up the challenge of closing the local water cycle and limiting the use of groundwater for purposes other than households. The solution was developed based on consultations with stakeholders and research results, with particular emphasis on microbiology. Water quality was compared to the requirements of European Union law. The developed solution consists in recovering water from municipal sewage for the internal needs of wastewater treatment plant and for the needs of municipal services. Reclaimed water can be used to wash equipment, power heat pumps, irrigate green areas, and clean streets. The social and environmental benefits consist in reducing the consumption of water from the drinking water network, building the value of water services and environmental corporate responsibility.

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Paweł Malinowski, Wojciech Dąbrowski, Sylwia Bagińska, Beata Karolinczak

Constructed wetlands (CW) plants are successfully used for treating various types of wastewater. Their most popular use is for the treatment of domestic sewage. The main aim of this research is to assess the change of microbiological parameters (total coliform, faecal coliform, total number of mesophilic and cryophilic bacteria, number of enterococci) during domestic sewage treatment in two CW beds with different fillings. The concentration of organic matter BOD5, COD), total Kjeldahl nitrogen TKN, ammonia nitrogen NH4–N, and total phosphorus were also analyzed. The research installation was based on two vertical subsurface flow constructed wetlands (VS-SF CW) – the first one filled with a Certyd aggregate and the second one with mineral material. Both beds were planted with reeds and worked in parallel with the same hydraulic load 0.1 m3/m2·d (m/d). The research was conducted during vegetative and non-vegetative seasons. Both beds showed a high effectiveness of reduction of most microbiological parameters, amounting to over 95%. The removal efficiency of the total coliform (TC) and faecal coliform (FC) parameters for the Certyd bed during the vegetative season was 99.9%, 98.3% and 97.51%, respectively in the non-vegetative season. In contrast, for the mineral-filled bed, the TC and FC removal efficiency during the vegetative season were, respectively 78.1% and 74.3%, respectively, 65.7% and 58.9% in the non-vegetative season. A difference in efficiency was observed depending on the season. High removal efficiencies of organic matter (measured by BOD5, COD values) and nutrient compounds was observed during the study. The conducted research proved a high efficiency of constructed wetlands in removing microbiological and chemical parameters. Overall, higher efficiency was observed in the bed filled with Certyd.

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Justyna Walczak, Beata Karolinczak, Monika Żubrowska-Sudoł

The study objective was to investigate the applicability of co-digestion and/or hydrodynamic disintegration as potential methods of methane production intensification from sewage sludge (SS) and the organic fraction of municipal solid waste (OFMSW) with consideration of carbon footprint (CF) assessment. Methane production was determined by means of biochemical methane potential tests. For co-digestion, the highest increase in methane production (53.8%) was observed for the SS:OFMSW mixing ratio 40:60. Hydrodynamic disintegration at all tested energy densities (10, 30 and 60 kJ/L) caused release of soluble organic compounds from both substrates, although accelerated methane production was only observed at 10 kJ/L. An increase in methane potential for substrates disintegrated separately did not imply analogical results for the disintegration of their mixture. Within the assumed limits, CF per 1Nm3 of produced methane, CF per 1t of wet feedstock for the digester, and estimated CF per 1  kW h produced were also calculated. Comparable values of all indicators were obtained for monodigestion and co-digestion. The highest CF indices were achieved for monodigestion of disintegrated SS and increased significantly with applied energy density. The obtained results can serve as valuable material for operators of wastewater treatment plants facilitating the selection of sustainable methods of increasing renewable energy production.

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Klara Ramm, Marzena Smol

In 2020, the European Commission (EC) defined a legal requirement for water reuse for agricultural purposes in the European Union (EU). EU Regulation (2020/741) on minimum requirements for water reuse should mobilize member states to implement solutions for the use of reclaimed water. This paper aims to examine the state of implementation of the provisions of this Regulation at the time of its entry into force. Based on desk research, the legal status of water reuse in EU countries, with particular emphasis on the issues of reclaimed water quality and its applications, was analyzed. The state of implementation of solutions regulating water reuse varies significantly across the EU’s countries. Central and Eastern European (e.g., Poland, Germany, Latvia, Lithuania, Estonia) countries are in no rush to regulate water reuse in agriculture; some will take advantage of the derogation to gain more time to consider it. Southern countries (e.g., Greece, Italy, France, Spain) are the most advanced and have experience in practical implementations gained before the Regulation was introduced. However, they use different quality control parameters. For now, France, Greece, Portugal, and Spain have fully implemented EC Regulation (2020/741); Belgium, Hungary, and Italy have partially implemented it; Malta has implemented it practically but not formally; and Cyprus has implemented it in distributed regulations. It should be pointed out that the potential for water reuse in the EU is significant, and this process is needed due to climate change consequences for Europe’s water resources. Therefore, further initiatives are expected, including the implementation by other countries of the provisions of Regulation (2020/741) in the coming decades.

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Marcin Kawka, Joanna Strużewska, Jacek W. Kamiński

High 𝑃𝑀10 concentrations are still a significant problem in many parts of the world. In many countries, including Poland, 50 μg/m3 is the permissible threshold for a daily average 𝑃𝑀10 concentration. The number of people affected by this threshold’s exceedance is challenging to estimate and requires high-resolution concentration maps. This paper presents an application of random forests for downscaling regional model air quality results. As policymakers and other end users are eager to receive detailed-resolution 𝑃𝑀10 concentration maps, we propose a technique that utilizes the results of a regional CTM (GEM-AQ, with 2.5 km resolution) and a local Gaussian plume model. As a result, we receive a detailed, 250 m resolution 𝑃𝑀10 distribution, which represents the complex emission pattern in a foothill area in southern Poland. The random forest results are highly consistent with the GEM-AQ and observed concentrations. We also discuss different strategies of training random forest on data using additional features and selecting target variables.

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Justyna Walczak, Aleksandra Dzido, Honorata Jankowska, Piotr Krawczyk, Monika Żubrowska-Sudoł

Until recently, sewage sludge produced in wastewater treatment processes was considered problematic waste. It currently constitutes a valuable substrate for raw materials and energy recovery. One of the methods of intensifying resource recovery from sludge is its pretreatment by means of disintegration methods. This study presents the CFD modelling and experimentally investigates the use of a hydrodynamic cavitation rotor operated with various rotational speeds (1500, 2500, and 300 rpm) for the recovery of organic compounds, nutrients, and energy. Rheological properties of raw sludge, a non-Newtonian fluid, were determined and used in the modelling calculations. Cavitation zones were observed for 2500 rpm and 3000 rpm, although a stronger cavitation effect occurred for a rotational speed of 3000 rpm. A rotational speed of 1500 rpm was too low to generate a pressure drop below 1705 Pa, and no cavitation was recorded. An increase in rotational speed from 1500 rpm to 3000 rpm for each analysed energy density caused an increase in SCOD and nitrogen concentration. Moreover, it was determined that at low energy densities (<105 kJ/L), mechanical tearing was the dominant factor responsible for carbon recovery, and at its higher values (≥105 kJ/L), the cavitation phenomenon became increasingly important. Rotation speed also had a significant effect on methane yield (YCH4). An increase in YCH4 by 6.2% was recorded only for disintegrated sludge at a rotational speed of 1500 rpm in reference to untreated sludge. Disintegration conducted at higher rotational speeds led to a decrease in YCH4 (-0.7% for 2500 rpm and -7.9% for 3000 rpm).

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Adam Muszyński, Monika Załęska-Radziwiłł

Two lab-scale sequencing batch reactors were seeded with flocculent activated sludge from a fullscale wastewater treatment plant, fed with synthetic wastewater with acetate as the only source of
organic carbon and operated in anoxic-anaerobic-aerobic (SBR1) and truly aerobic modes (SBR2). In SBR1 granules were formed, while flocs in aerobic SBR2 were overgrown with filamentous bacteria.
FISH showed that synthetic wastewater equally influenced the abundance of bacterial phyla and classes in both SBRs regardless the operating mode: Proteobacteria increased their abundance
and outcompeted Chloroflexi and Actinobacteria, Betaproteobacteria was the dominant class, abundance of Alphaproteobacteria decreased, and Gammaproteobacteria remained stable. The anoxic-
anaerobic-aerobic conditions and acetate favoured growth of polyphosphate (PAO) and glycogen accumulating organisms (GAO) in SBR1, whereas the aerobic conditions in SBR2, along with
the acetate, triggered growth of filamentous Thiothrix/021N. Despite the large differences between the abundance of PAO/GAO in both SBRs, the composition of their populations did not differ significantly
between reactors, and the type of organic substrate was a decisive factor shaping the structure of their communities. Tetrasphaera PAO, predominant in the seed, were outcompeted in
both SBRs by Accumulibacter. Clades IA and IIA, C, D together constituted 78% and 73% of the Accumulibacter lineage in SBR1 and SBR2, respectively, whereas 97% of Accumulibacter in the seed
was not targeted by any of the clade-specific probes. Defluviicoccus vanus cluster 2 was partially replaced by cluster 1 and Competibacter in both SBRs. The substantial abundance of PAO in SBR1
was reflected in the high enhanced biological phosphorus removal activity in anaerobic batch tests and high presence of intracellular polyphosphate granules at the end of the aerobic period.
Despite the significant abundance of Accumulibacter, the biomass from SBR2 neither released P nor took up Corg in anaerobic batch tests, which indicates that the activity of ecophysiological
groups was largely influenced by the mode of operating bioreactors.

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Aleksandra Bogdanowicz, Andrzej Ryszard Krasiński, Monika Żubrowska-Sudoł

The separation of microplastics from water using the filtration process was studied in this work. The deep-bed filter media were made of polypropylene using the melt-blown technique. The separation
performance of these filters was compared to the pleated cellulose elements (surface filtration) for the prepared suspension of fragmented polystyrene particles. No pretreatment nor additives to
enhance the separation process were applied upstream the filtration unit. With the increased filter efficiency (rating of depth filters ranging from 20 to 5 μ), the cut-off dimeter of removed microplastic
also decreased. The experiments confirmed that deep bed filtration is capable to remove efficiently very fine microplastic particles (as small as 1 μ), while maintaining relatively low pressure
drop. The capacity of the deep bed filter will guarantee relatively long operation time for suspensions having a low concentration of MPs, however in real process this will probably be predominantly
affected by the simultaneous deposition of other solid contaminants present in the water.

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Paweł Popielski, Bartosz Bednarz, Tomasz Majewski, Maciej Niedostatkiewicz

The research paper reviews issues associated with the impact of groundwater flow on soil characteristics and parameters, hence, the entire structure of a building set on it.Water seepage through the ground, building subsoil or structural elements of buildings made of soil affects the soil skeleton and may lead to changes in the arrangement of individual grains relative to each other, i.e., a modified soil structure. Soil solid phase (soil skeleton) deformations resulting from seepage forces are called seepage-induced deformations. The article characterizes typical seepage-induced deformations and specifies a criterion defining the beginning of the phenomenon. The case study involved using data on cracks and deformations in a historic building, as well as water seepage in its subsoil. Seepage was analysed, and zones where the seepage process initiation criterion was exceeded, were determined based on subsoil water level monitoring data. The determined zones coincide with the location of building cracks and scratches and confirm the possible cause behind building damage.

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Pola Sylwana Łomża-Kalinowska, Tomasz Krucoń, Agnieszka Tabernacka

Halogenated organic compounds (HOCs) pose a serious problem for the environment. Many are highly toxic and accumulate both in soil and in organisms. Their biological transformation takes place by dehalogenation, in which the halogen substituents are detached from the carbon in the organic compound by enzymes produced by microorganisms. This increases the compounds’ water solubility and bioavailability, reduces toxicity, and allows the resulting compound to become more susceptible to biodegradation. The microbial halogen cycle in soil is an important part of global dehalogenation processes. The aim of the study was to examine the potential of microbial communities inhabiting natural and anthropogenically modified environments to carry out the dehalogenation process. The potential of microorganisms was assessed by analyzing the metagenomes from a natural environment (forest soils) and from environments subjected to anthropopression (agricultural soil and sludge from wastewater treatment plants). Thirteen genes encoding enzymes with dehalogenase activity were identified in the metagenomes of both environments, among which, 2-haloacid dehalogenase and catechol 2,3-dioxygenase were the most abundant genes. Comparative analysis, based on comparing taxonomy, identified genes, total halogens content and content of DDT derivatives, demonstrated the ability of microorganisms to transform HOCs in both environments, indicating the presence of these compounds in the environment for a long period of time and the adaptive need to develop mechanisms for their detoxification. Metagenome analyses and comparative analyses indicate the genetic potential of microorganisms of both environments to carry out dehalogenation processes, including dehalogenation of anthropogenic HOCs.

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Piotr Dąbrowiecki, Andrzej Chciałowski, Agata Dąbrowiecka, Anna Piórkowska, Artur Jerzy Badyda

Allergic rhinitis (AR) affects 10 % of the world population, with an increased prevalence in regions with substantial air pollution, but the association between exposure to air pollutants and the short-term risk of AR exacerbations is unclear. We used a time-series approach to analyze the risk of hospital admissions due to AR over 8 days from exposure to various air pollutants. Distributed lag nonlinear models were used to analyze data gathered between 2012 and 2018 in the three largest urban agglomerations in Poland. The analyses were carried out separately for the warm (April – September) and cold seasons (October – March). Overall, there were 1407 admissions due to AR. In the warm season, the rate ratio (95 % confidence interval) for admission per 10 µg/m3 was 1.202 (1.044, 1.384) for particulate matter less than 10 µm (PM10); 1.094 (0.896, 1.335) for particulate matter less than 2.5 µm (PM2.5); 0.946 (0.826, 1.085) for nitrogen dioxide (NO2); 0.837 (0.418, 1.677) for sulfur dioxide (SO2); and 1.112 (1.011, 1.224) for ozone (O3). In the cold season, the rate ratio for admission per 10 µg/m3 was 1.035 (0.985, 1.088) for PM10; 1.041 (0.977, 1.108) for PM2.5; 1.252 (1.122, 1.398) for NO2; 0.921 (0.717, 1.181) for SO2; and 1.030 (1.011, 1.050) for O3. In conclusion, the risk of admission due to AR increased significantly after exposure to O3 in the warm and cold seasons. Exposure to PM10 was associated with a significantly increased risk of AR hospitalizations in the warm season only, whereas exposure to NO2 was associated with a significantly increased risk of AR admission in the cold season.

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Michał Sobieraj, Dariusz Ksionek, Branimir Pavković

The solid-liquid equilibrium (SLE) of binary systems containing carbon dioxide (R744) and alkanes propane (R290) and isobutane (R600a) was experimentally investigated. A novel experimental setup using the cooling curve method was designed, built and verified, enabling SLE measurements at temperatures down to 173 K. The temperature and pressure of the triple point of carbon dioxide (CO2) were measured. The results for R744 and the binary mixture of carbon dioxide and propane were in agreement with the available literature data, demonstrating the accuracy of the experimental setup. Activity coefficients were determined for the binary mixtures studied. The Schröder and Wilson equations were used to calculate solubility over various temperatures and compositions. The Wilson model produced a very accurate correlation for the studied non-ideal binary mixtures, while the Schröder equation did not provide satisfactory results. Determined activity coefficients and SLE curves should be useful for the design of low-temperature refrigeration systems operating on carbon dioxide mixtures with low global warming potential.

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Maciej Malarski, Piotr Wichowski, Justyna Czajkowska

Composting enables the recycling of significant amounts of biodegradable waste, while ensuring its disposal. The addition of fly ash increases the concentration of fertilizing substances in the compost. Compost is a source of many nutrients for plants. The addition of fly ash might also cause a slower release of these nutrients into an aqueous solution, meeting the fertilization needs of plants over a longer period of time. Tests were carried out using sewage sludge (WWTP Piaseczno, 163,500 P.E.), straw as a structure-forming material and fly ash (WWTP Krakow, 780,000 P.E.). The compost obtained in the research was analyzed in terms of environmental conditions specified in legal regulations. The most favorable compost mass density (520 kg/L) and the amount of air supplied to the process (5.0 L/(h∙kg d.m.)) were determined. The addition of fly ash to the compost mass did not significantly affect the temperature distribution obtained in the process. The increase in fly ash content increased the pH of the compost mass and was associated with higher nitrogen losses. It was found that the factor which may limit the possibility of using fly ash as a compost substrate is the presence of higher concentrations of heavy metals, especially chromium. It was determined that the maximum addition of fly ash to the compost mass was 154 kg d.m.ash/(ton d.m.straw+sludge).

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Łukasz Szarek, Paweł Falaciński, Piotr Drużyński

In recent years, there has been a marked increase in the amount of municipal waste generated in Poland. In 2020, 21.6% of all municipal waste was subjected to a thermal treatment process. Consequently, the
amount of ashes generated is significant. Due to their properties, it is difficult to utilize this type of waste within concrete production technology. One of the waste utilization methods is to add it to hardening slurries used in, among others, cut-off walls. The article assesses the possibility of using ashes from municipal waste incineration as an additive to hardening slurries. It also discusses the technological properties of hardening slurries with the addition of the ashes in question. The experiment showed that it is possible to compose a hardening slurry based on tested ashes with technological properties suitable for use as a cut-off wall. Further research directions were proposed.

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Dominika Ścieżyńska, Dominika Bury, Michał Jakubczak, Jan Bogacki, Agnieszka Jastrzębska, Piotr Marcinowski

In an era of increasing environmental awareness, it is very important to work towards eliminating or at least reducing as many harmful industrial substances as possible. However, the implementation of green chemistry methods for wastewater treatment can be difficult especially due to complexity, the high cost of reagents, and the required long process time. This paper focuses on using waste iron (WI) to remove two kinds of amaranth dye commonly used in industry. To enhance the process, UV irradiation and hydrogen peroxide were used. The novelty of the research was the use of efficient and reusable WI as a heterogeneous catalyst in the process. WI material characteristics was done before and after the process using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Zeta potential, size characterization, circularity, and direct band gap were also determined. As a result of treatment complete decolorization of both dyes was achieved, as well as 99% absorbance removal after 15-min process time. The total organic carbon (TOC) decrease after 60-min process time was in the range from 86.6 to 89.8%. Modified pseudo-second-order reaction reflects obtained results of treatment efficiency. Treatment results, confirmed by WI material characterization, indicate satisfactory stability of the catalyst and good oxidation capacity.

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Dominika Bury, Michał Jakubczak, Jan Bogacki, Piotr Marcinowski, Agnieszka Jastrzębska

The Ti3C2Tx MXene is a novel two-dimensional (2D) material with unique optical properties and excellent water dispersibility related to rich surface termination. This study uses its properties to design an innovative magnetic catalyst made of waste iron chips (WI), surface-modified with a 2D Ti3C2Tx MXene. We further utilize it to advance a heterogeneous Fenton process for industrial dye removal. Novel WI-MXene nanocomposite catalyst overcame difficulties associated with the acidic pH range, frequently required for efficient generation of reactive oxygen species (ROS) via Fe (II) activity. The photo-active 2D MXene enabled the WI-MXene catalyst activation in the visible light range and near-neutral pH with excellent performance in decomposing model organic dye – methylene blue (MB). The novel catalyst showed over 95 % efficiency in decomposing MB upon UV light irradiation at pH = 5 and about 62 % in decomposing the total organic carbon (TOC). Since the WI-MXene had a band gap of about 1 eV, it also showed a tunable activity toward specific light ranges. The irradiation with 550 nm (cyan) light gave the highest photo-Fenton efficiency. Analysis of the fundamental process mechanism showed a massive ROS evolution and a minor adsorption activity of WI-MXene toward decomposed dye. The post-process stability analysis did not show any changes in the WI-MXene structure. Further regeneration of spent WI-MXene enabled its reuse with 90 % efficiency at various pH values. Collectively, the obtained results show a high potential for MXene-enabled photo-Fenton processes.

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Łukasz Krysiak, Zbigniew Kledyński, Agnieszka Machowska

The amount and variety of waste materials used in civil engineering are steadily increasing due to the depletion of natural resources and the implementation of environmental policies. A new mixture of colliery spoils and fluidized bed bottom ash was recently developed in Poland, which proved to be prone to excessive, long-term swelling, potentially damaging structures such as road embankments. Numerous papers discuss the heaving mechanisms in spoils or fluidized bed ash. However, no reports analyzing the expansion of their mixture seem to be available. The purpose of this paper is to fill this void. The experiment involved measurements of linear swelling of mixture samples stored inside CBR test molds and isolated from moisture loss/gain. Material expansion is caused by the reactivity of the fluidized bed ash; its content in the mix correlates positively with the final swelling strain. At the same time, colliery spoils provide an environment particularly conducive to the phenomenon’s occurrence. A linear swelling strain of 0.3–3.2% was observed after 6 months (disregarding the first 24 h of rapid volume growth). The expansion of mixtures was also measured under constant compressive stress of 0–100 kPa to better represent their actual working conditions. Based on the results, it is proposed to adapt a mathematical model developed for anhydrite-rich rock to describe the load-swelling relationship in mixtures of colliery spoils with fluidized bed bottom ash. Such a model can be potentially used, e.g., in numerical analyses, to assess the impact of the material’s expansion on embankments.

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Agnieszka Garlicka, Przemysław Kupidura, Piotr Krawczyk, Katarzyna Umiejewska, Adam Muszyński

Circular economy model, based on the “make, use, reuse, remake, recycle” approach, is an alternative to progressive depletion of non-renewable fossil fuels. Sewage sludge can be a source of renewable energy obtained through the anaerobic conversion of their organic fraction into biogas. This process is mediated by highly complex microbial communities and its efficiency depends on the availability of substrates to microorganisms. Disintegration of the feedstock in the pre-treatment step may intensify the anaerobic digestion, but re-flocculation of disintegrated sludge (reassembly of the released fractions into larger agglomerates) may result in a reduced availability of the released organic compounds for microbes. Pilot-scale studies on re-flocculation of disintegrated sludge were conducted to select parameters for scaling-up the pre-treatment and intensifying the anaerobic digestion process in two large Polish wastewater treatment plants (WWTPs). Samples of thickened excess sludge from full-scale WWTPs were subjected to hydrodynamic disintegration at three energy density levels of 10 kJ/L, 35 kJ/L and 70 kJ/L. Microscopic analyses of disintegrated sludge samples were carried out twice: i) immediately after the disintegration process at a given energy density level, ii) and after 24-h incubation at 4 °C following the disintegration. Micro-photographs of 30 randomly selected fields of view were taken for each analysed sample. A method of the image analysis was developed as a tool to measure dispersion of sludge flocs to assess the re-flocculation degree. Re-flocculation of the thickened excess sludge occurred within 24 h after hydrodynamic disintegration. This was evidenced by a very high re-flocculation degree, reaching up to 86%, depending on the origin of the sludge and the energy density levels used for the hydrodynamic disintegration.

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Dominika Bury, Michał Jakubczak, Rajiv Kumar, Dominika Ścieżyńska, Jan Bogacki, Piotr Marcinowski, Agnieszka Jastrzębska

Rapid global industrialization constantly impacts the environment by discharging pollutants. Therefore, various materials are currently being investigated for environmental applications, including two-dimensional (2D) MXenes. Herein, we focus on MXene-enabled technologies for removing inorganic and organic contaminants present in gaseous and liquid forms, especially organic dyes, pharmaceuticals, and solid pollutants. We foresee a considerable potential for MXene-enabled technologies to remove heavy ions and radionuclides and recover precious elements. We show that MXenes could efficiently inactivate microorganisms without harming the environment. Finally, we discuss the associated opportunities and challenges in MXenes’ surface chemistry, semiconducting activity, interfacial effects, adsorption, and photocatalysis. Altogether, this article showcases outstanding opportunities for MXenes in the rapidly growing field of environmental applications.

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Karol Michał Przeździecki, Jarosław Zawadzki

Nowadays, climate change and heat extremes are becoming highly challenging problems in many cities across the globe. One of the solutions to overcome this problem is the use of vegetation, and, in particular, extending the range of overgrown areas, which are sometimes referred to as “urban green areas.” In this paper, the moisture condition and its mitigating effect on Land Surface Temperature in urban areas were examined in Warsaw, Poland, using satellite data. To do so, the so-called “Triangle Method” was employed. The triangle method is based on a Land Surface Temperature–Normalized Difference Vegetation Index (LSTNDVI) scatterplot to calculate the Temperature Vegetation Dryness Index (TVDI) and its modification–quadratic Temperature Vegetation Dryness Index (qTVDI). This article discusses, in detail, the usefulness of the triangle method for the analyses of built-up areas. The drought satellite indices TVDI and qTVDI compared with those of LST, NDVI, and NDBI (Normalized Difference Building Index). The study shows that the triangle method based on LSTNDVI scatterplot analysis is a promising tool for establishing moisture conditions over urban areas and for studying the effect of vegetation impact on urban heat islands. Detailed analysis shows that over an urban area, qTVDI shows better agreement with LST than classic TVDI.

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Radosław Czernych, Artur Jerzy Badyda, Grzegorz Kozera, Paweł Zagożdżon

(1) Background: More than 1.8 million people in the European Union die every year as a result of CVD, accounting for 36% of all deaths with a large proportion being premature (before the age of 65). There are more than 300 different risk factors of CVD, known and air pollution is one of them. The aim of this study was to investigate whether daily cardiovascular mortality was associated with air pollutants and meteorological conditions in an urban environment with a low level of air pollution. (2) Methods: Data on daily incidence of strokes and myocardial infarctions in the city of Gdansk were obtained from the National Health Fund (NHF) and covered the period from 1 January 2014 to 31 December 2018. Data on the level of pollution, i.e., SO2, NO, NO2, NOx, CO, PM10, PM2.5, CO2, O3 and meteorological conditions came from the foundation: Agency of Regional Air Quality Monitoring in the Gdańsk metropolitan area (ARMAG). Using these data, we calculated mean values with standard deviation (SD) and derived the minimum and maximum values and interquartile range (IQR). Time series regression with Poisson distribution was used in statistical analysis. (4) Results: Stroke incidence is significantly affected by an increase in concentrations of NO, NO2 and NOx with RRs equal to 1.019 (95%CI: 1.001–1.036), 1.036 (95%CI: 1.008–1.064) and 1.017 (95%CI: 1.000–1.034) for every increase in IQR by 14.12, 14.62 and 22.62 μg/m3, respectively. Similarly, myocardial infarction incidence is significantly affected by an increase in concentrations of NO, NO2 and NOx with RRs equal to 1.030 (95%CI: 1.011–1.048), 1.053 (95%CI: 1.024–1.082) and 1.027 (95%CI: 1.010–1.045) for every increase in IQR by 14.12, 14.62 and 22.62 μg/m3, respectively. Both PM10 and PM2.5 were positively associated with myocardial infarction incidence. (5) Conclusions: In this time-series cross-sectional study, we found strong evidence that support the hypothesis that transient elevations in ambient PM2.5, PM10, NO2, SO2 and CO are associated with higher relative risk of ischemic stroke and myocardial infarction incidents.

Łukasz Dominik Kaczmarek, Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Mateusz Grygoruk, Małgorzata Jastrzębska, Jan Szatyłowicz

The characteristics of peat’s are crucial for understanding natural processes and their suitable shaping through the management of water relations. This study focused on the results of one of the first hydraulic conductivity (k) laboratory tests of exemplary peat samples from the Biebrza Valley (a peatland of very high environmental importance) in relation to the stress state and hydraulic gradient. Further, the research was devoted to a specific test procedure of peat permeability as a key feature for landform development in wetlands. Detailed tests of dark brown/black samples were selected as the reference for the research investigations. Four long-term test series of water permeability were performed in a modified triaxial compression apparatus. In all selected hydraulic gradient variants (i = 5,10,25,40,55,85), the k values decreased from 6 × 10−8 m/s to 1.6 × 10−10 m/s with a stepwise increase in the effective confining pressures tested (10, 15, 30, 45, and 90 kPa). These results were related to the inherent soil features—a relatively high peat decomposition and external driver—confining pressure (radial stress) magnitude. Compared to the other Polish peat tests, the determined k values were at the lower end of their hydraulic conductivity range. The analysed organic soil is not a typical aquifer. Despite very high porosities (~88%) and a high organic matter content (81.1–89.4%) which is favourable for water accumulation, the characterized peat showed relatively low hydraulic conductivity values. Thus, this specific soil may differentiate the groundwater flow as it complicates strong contact with surface water.

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Agnieszka Garlicka, Katarzyna Umiejewska, Per Halkjær Nielsen, Adam Muszyński

The aim of this project was to study the combination of two methods to increase methane production: feedstock pretreatment by hydrodynamic disintegration and co-digestion of maize silage (MS) with thickened excess sludge (TES). Disintegration of TES alone resulted in a 15% increase in specific methane production from 0.192 Nml/gVS (TES + MS) to 0.220 Nml/gVS (pretreated TES + MS). The energy balance revealed additional energy (0.14 Wh) would cover only the energy expenditure for the mechanical pretreatment and would not allow for net energy profit. Identification of the methanogenic consortia by 16S rRNA gene amplicon sequencing revealed that Chloroflexi, Bacteroidota, Firmicutes, Proteobacteria and Actinobacteriota were five most abundant bacteria phyla, with Methanothrix and Methanolinea as the dominant methanogens. Principal component analysis did not show any effect of feedstock pretreatment on methanogenic consortia. Instead, the composition of inoculum was the decisive factor in shaping the microbial community structure.

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Karol Michał Przeździecki, Jarosław Zawadzki, Marek Urbaniak, Klaudia Ziemblińska, Z. Miatkowski

Land Surface Temperature (LST) against Vegetation Index (VI) scatterplot is a base concept of Temperature Vegetation Dryness Index (TVDI) which is a widely used drought index taking into account evaporation over heterogenic area. The main advantage of using TVDI is that it reflects rather a soil moisture conditions than volumetric soil moisture itself. This is particularly useful when the aim of conducting research is to assess water availability for plants rather than volumetric soil moisture at some depth. Results that have been obtained so far using indices based on LST-VI scatterplot proved their effectiveness in meadows, pastures or crops but were not satisfactory enough over forest areas. An important limitation of using TVDI is a need to collect LST and VI data from heterogenic areas, to provide different soil moisture conditions which is often difficult to ensure.In this paper, we proposed a new approach to the TVDI calculation method in which we use temporal variability of soil moisture conditions (shown in different satellite images of the same area) instead of their spatial heterogeneity.Calculations were conducted over the forest area in Tuczno Poland. To calculate the temporal TVDI model 4 Landsat 8 OLI/TIRS scenes were used, and calculation was performed in Python 3 using open-source packages. The average moisture conditions of each chosen scene were validated using field data, namely evapotranspiration determined from an eddy covariance.

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Olga Zając, Monika Żubrowska-Sudoł, Martyna Godzieba, Sławomir Ciesielski

Nitrification is considered one of the most temperature-sensitive biological steps in wastewater treatment. Nitrifying bacteria are highly sensitive to temperature drops, resulting in a rapid decrease
in their activity. This study compares the effect of a rapid temperature decrease on the ammonia oxidation rate (AOR) and nitrite oxidation rate (NitOR), with consideration of the form in which
biomass develops in the IFAS-MBSBBR. Ammonia Utilisation Rate Tests and Nitrite Utilisation Rate Tests were conducted for two temperatures, namely 20°C and 12°C, for the following forms
of biomass: activated sludge (AS), biofilm (B), and combination of both – hybrid (H). The tests showed that nitrite oxidising bacteria inhabiting biofilm were more sensitive to a rapid temperature
change than those in activated sludge. A sudden drop of temperature caused a 15% higher than predicted decrease in AOR for AS. At 12°C, AOR changed more considerably than NitOR in tests
carried out for H. A temperature correction coefficient of 1.107–1.087 was proposed, applicable in hybrid wastewater treatment systems. Microbiological analysis shows that nitrifiers occurred more
abundantly in biofilm than in activated sludge.

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Piotr Dąbrowiecki, Andrzej Chciałowski, Agata Dąbrowiecka, Anna Piórkowska, Artur Jerzy Badyda

Introduction: Airborne pollutants may worsen the course of chronic obstructive pulmonary disease (COPD). Previous studies have shown that both particulate and gaseous pollutants increase airway inflammation, which may lead to an exacerbation of COPD. Objectives: To study the association between exposure to airborne pollutants and the risk of COPD exacerbations in the three largest urban agglomerations in Poland: Warsaw, Cracow, and the Tricity. Patients and methods: We used a case-crossover approach to analyze data from 2011 to 2018. This time-series study used distributed lag nonlinear models to analyze the risk of hospital admission due to COPD exacerbations during 21 days following exposure to particulate matter (PM), NO2, and SO2. Results: Overall, there were 26,948 admissions due to COPD exacerbations. During 21 days after exposure, the rate ratio (95% confidence interval) for admissions per 10 μg/m3 was 1.028 (1.008-1.049) for PM10; 1.030 (1.006-1.055) for PM2.5; 1.032 (0.988-1.078 for NO2; and 1.145 (1.038-1.262) for SO2. The risk for admission peaked at 10 days after exposure to PM10 and PM2.5, whereas for NO2 and SO2 the risk was greatest on the day of exposure. The proportions (95% confidence interval) of hospitalizations attributable to air pollution were 9.08% (3.10%-15.08%) for PM10; 7.61% (1.27%-13.49%) for PM2.5; 9.77% (3.63%-21.48%) for NO2; and 7.70% (2.30%- 12.84%) for SO2. Conclusions: PM2.5, PM10, NO2, and SO2 pollution was associated with an increased risk of COPD exacerbations that needed treatment in hospital. There were different risk patterns for particulate and gaseous pollutants. Improving air quality in Polish cities could reduce the burden of COPD.

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Nina Doskocz, Monika Załęska-Radziwiłł

The widespread use of nanoparticles leads to their presence in wastewater, landfills and migration to the environment, especially to water and soil. However, while the lists of known toxic effects of
nanoparticles continue to grow, there is still a vast gap in our knowledge about their harmfulness. In this study, SOS Chromotest and comet assay were used to the genotoxicity of aluminum oxide
nanoparticles (Al2O3 NPs) using Escherichia coli bacteria and erythrocytes of Cyprinus carpio. Al2O3 NPs are used by military and commercial industries in many applications. The analysis of the obtained
results showed that the tested nanoparticles can potentially cause changes in the genetic material of the bioindicators. Results of genotoxicity induction coefficient (I) values in the SOS Chromotest
clearly showed the genotoxicity of Al2O3 NPs, both in the presence and in the absence of S9 fraction. In turn, the statistical analysis of the comet assay test results showed a significant increase of ‘%
DNA in tail’ and ‘tail length’ of comets in cells populations incubated in solutions of Al2O3 NPs compared to the negative control. Furthermore, the obtained results showed that the nanoparticles had
a greater effect on the genetic material of bacteria and eukaryotic cells than their bulk counterparts.

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Thanh-Nhan-Duc Tran, Binh Quang Nguyen, Runze Zhang, Aashutosh Aryal, Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Venkataraman Lakshmi

Many fields have identified an increasing need to use global satellite precipitation products for hydrological applications, especially in ungauged basins. In this study, we conduct a comprehensive evaluation of three Satellite-based Precipitation Products (SPPs): Integrated Multi–satellitE Retrievals for GPM (IMERG) Final run V6, Soil Moisture to Rain (SM2RAIN)-Advanced SCATterometer (ASCAT) V1.5, and Multi-Source Weighted-Ensemble Precipitation (MSWEP) V2.2 for a subbasin of the Mekong River Basin (MRB). The study area of the Srepok River basin (SRB) represents the Central Highland sub-climatic zone in Vietnam under the impacts of newly built reservoirs during 2001–2018. In this study, our evaluation was performed using the Rainfall Assessment Framework (RAF) with two separated parts: (1) an intercomparison of rainfall characteristics between rain gauges and SPPs; and (2) a hydrological comparison of simulated streamflow driven by SPPs and rain gauges. Several key findings are: (1) IMERGF-V6 shows the highest performance compared to other SPP products, followed by SM2RAIN-ASCAT V1.5 and MSWEP V2.2 over assessments in the RAF framework; (2) MSWEP V2.2 shows discrepancies during the dry and wet seasons, exhibiting very low correlation compared to rain gauges when the precipitation intensity is greater than 15 mm/day; (3) SM2RAIN–ASCAT V1.5 is ranked as the second best SPP, after IMERGF-V6, and shows good streamflow simulation, but overestimates the wet seasonal rainfall and underestimates the dry seasonal rainfall, especially when the precipitation intensity is greater than 20 mm/day, suggesting the need for a recalibration and validation of its algorithm; (4) SM2RAIN-ASCAT had the lowest bias score during the dry season, indicating the product’s usefulness for trend analysis and drought detection; and (5) RAF shows good performance to evaluate the performance of SPPs under the impacts of reservoirs, indicating a good framework for use in other similar studies. The results of this study are the first to reveal the performance of MSWEP V2.2 and SM2RAIN-ASCAT V1.5. Additionally, this study proposes a new rainfall assessment framework for a Vietnam basin which could support future studies when selecting suitable products for input into hydrological model simulations in similar regions.

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Dominika Ścieżyńska, Dominika Bury, Michał Jakubczak, Jan Bogacki, Agnieszka Jastrzębska, Piotr Marcinowski

Dyes are highly toxic and persistent in the environment. Their presence in water causes environmental and social problems. Dyes must be effectively removed from the water. A UV/ZVI/H2O2 process was applied to decompose two organic dyes, AM E123 and AM ACID. A commercial ZVI product, Ferox Flow, was used, and its properties were determined using SEM and XRF. The zeta potential, surface area, and optical properties of ZVI were also determined. The efficiency of dye removal in optimal conditions was 85.5% and 80.85% for AM E123 and AM ACID, respectively. Complete decolorization was observed in all samples. The decomposition of both dyes occurred according to a modified pseudo-second-order reaction and there was a statistically significant correlation between the TOC decrease, pH, and process time. The catalyst was observed to have high stability, and this was not affected by the performance of the treatment process even after the third cycle, as confirmed by the results of the catalyst surface analysis and iron diffusion test. Slight differences in process efficiency were observed after each cycle. The need for only a small amount of catalyst to decompose AM E123 and AM ACID, coupled with the ability to reuse the catalyst without the need for prior preparation, may reduce catalyst purchase costs.

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Krystyna Lelicińska-Serafin, Piotr Manczarski, Anna Rolewicz-Kalińska

Reducing the phenomenon of food waste and effective management of already wasted food in the form of post-consumer waste, included in the source-separated organic fraction of municipal solid waste (SS-OFMSW) from households and catering facilities, are some of the key challenges of the circular economy (CE), in particular in highly urbanized areas. The basis for the effective use of this waste is the knowledge of its physical and chemical properties. The main objective of the paper is to identify the key technological and organizational parameters for selective collection determining the characteristics of the SS-OFMSW and, consequently, the optimal path for its management. This paper presents the results of qualitative research of SS-OFMSW generated in the capital of Poland—Warsaw—coming from three sources: multi- and single-family housing and catering facilities. The collection efficiency of this waste was determined in the form of quality in container rate (QCR = 92–97%) and variability in terms of impurities and admixtures present in it (CV = 56–87%). High variability indicates that the system of selective waste collection in Warsaw is immature, which may hinder undertaking activities in the field of waste management planning. The study confirmed the suitability of the tested SS-OFMSW for organic recycling, especially using anaerobic digestion (AD), to which it is predisposed by water content, C/N, and biomethane potential (BMP). All tested food waste is characterized by a high yield of biogas in the range of 384–426 m3/Mg VS and an average share of methane in biogas at the level of 52–61%. Fertilizer properties, moisture, and its gas potential show little variability (CV ≤ 16%), which means that these data can be treated as stable data. The obtained results indicate the optimal direction for the collection and processing of SS-OFMSW based on post-consumer food waste in urbanized areas.

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Katarzyna Anna Affek, Nina Doskocz, Monika Załęska-Radziwiłł

Disinfection of treated wastewater and its reuse for breeding, agricultural or recreational purposes is a beneficial solution due to water deficits in the world. The risks associated with treated wastewater
disinfection include, among others, possibility of the formation of harmful by-products (DBPs). Unmonitored presence of DBPs in treated wastewater is potentially harmful to organisms in ecosystems
and to human health. The aim of the research was to compare the genotoxicity of treated wastewater from full-scale municipal wastewater treatment plant before and after the disinfection
process with peracetic acid with parameters ensuring satisfactory inactivation of microorganisms. Genotoxicity to Escherichia coli bacteria was tested with SOS Chromotest. The influence on
the genetic material of Daphnia magna crustaceans was determined by the random amplification of polymorphic DNA – polymerase chain reaction (RAPD-PCR). Treated wastewater before disinfection
showed genotoxicity to E. coli and D. magna. However, although treated wastewater disinfected with peracetic acid turned out to loose genotoxic potential to bacteria, it generated changes in the
genetic material of crustaceans exposed to wastewater after the disinfection process. Significant decrease in the genetic stability of DNA in RAPD-PCR was observed, which increased with the
extension of the disinfection time and the increasing concentration of the disinfectant. The conducted research confirms the genotoxic potential of treated wastewater before and after disinfection
with peracetic acid. Therefore, it may pose a threat to organisms of aquatic ecosystems when discharged into receiving reservoirs and reused in the event of a water shortage.

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Honorata Jankowska, Aleksandra Dzido, Piotr Krawczyk

Non-Newtonian fluids are commonly used in a wide range of industries; one example are in biogas power plants. Proper measurements and modeling of such fluids can be crucial from the design and operations point of view. Results presented in this study covered seven samples from three plants (a sewage sludge treatment plant, utilization biogas station and a biogas plant in a sugar factory), including mechanically thickened excessive activated sludge (MTEAS), sugar beet pulp (SBP), liquid fruit and vegetable waste (FVW), beet roots (BR) and corn waste (CW); their mixtures were prepared as in a real plant. The total solid content remained below 6.8% for all samples. The apparent viscosity (15 RPM) did not exceed 10 Pas in any sample. A correlation analysis for solvent type influence on the viscosity was carried out. The obtained results were analyzed, and the Herschel–Bulkley rheological model was selected for the fluid description. Then, the Moullinex method was applied to determine the H–B model parameters. The obtained results may contribute to the proper design and operation of various biogas power plants, in which viscosity seems to be one of the crucial flow parameters that influences the device types used, as well as energy consumption.

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Saddam Hashimov, Jarosław Zawadzki

The Absheron Peninsula is the biggest urbanized area in Azerbaijan. Along with the growth of the massive oil production, the role of the Peninsula has increased and big ecological problems have arisen. In this research, the investigation of the possibility of detecting hydrocarbons in sandy soil through Landsat 8 OLI and Sentinel 2 A satellite and drone images and chemical analysis was conducted. The main study was based on the satellite imagery of Landsat 8 OLI and Sentinel 2A, employing NDVI calculations and analyses. In order to calculate NDVI, ESRI ArcGIS 10.3 software has been used. The multispectral images with 30m spatial resolution of Landsat 8 and 10 m resolution multispectral images of Sentinel 2 were used. Additionally, drone observations lead to obtaining high-resolution data about soil pollution in the study area. Also, field samples were taken to the laboratory and necessary chemical analysis was performed for validation purposes. This study showed that multispectral remote sensing can be used to detect hydrocarbons in the soil in oil production areas. Hydrocarbon-bearing substances’ absorption into the soil results in a low value of NDVI in the study area. The observations in the winter and summer seasons show that the seasonal changes in weather conditions affect both the amount of oil contamination in the soil and the detection process of soil pollution by oil using remote sensing.

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Karol Michał Przeździecki, Jarosław Zawadzki

The temperature of a city’s surface is influenced by many factors, including human-dependent ones that can be shaped, such as the urban density, the condition of urban vegetation, the presence of urban water bodies, and soil moisture. Knowledge on this subject allows for improving the urban climate through better planning and construction of urban infrastructure and adapting cities to climate change and avoiding deadly heat waves increasingly threatening European cities. So far, mainly the first three factors have been studied particularly well, while there is no in-depth research on the impact of soil moisture on a city’s climate in the literature. This article fills this gap by analyzing the impact of all the abovementioned factors on the temperature of the city’s surface in Warsaw, a large European urban agglomeration, located in a temperate climate zone. Due to the exceptionally large war damage to Warsaw during World War II, rapid postwar reconstruction, and significant expansion, the city is characterized by a very large diversity of urban development density and a much larger amount of green areas compared to most large cities, such as old Western European agglomerations. The scientific novelty of the work is also the fact that the soil moisture content was analyzed using the TVDI/qTVDI (Temperature Vegetation Dryness Index Estimation) indexes obtained by using the so-called triangle methods in NDVI-LST space, based on satellite observations. Such analyses have not been performed so far in urban areas, while in the article, many new results were obtained on this subject. For example, Pearson’s correlation coefficients between LST, NDBI, NDVI, and qTVDI calculated for the entire area of Warsaw on 8 August 2020 were 0.78, 0.45, and −0.35, respectively. Another important aspect of the work is that it includes comparative studies of the impact of the abovementioned factors on the temperature of the Earth’s surface at the level of different city districts. As a result, it was possible to more effectively study the impact of the abovementioned factors on the temperature of the Earth’s surface at the scale of local administrative units. Thanks to the obtained results, urban planners will be able to reduce urban hazard risks caused by climate change.

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Karolina Maria Szałkowska, Monika Żubrowska-Sudoł

Water shortages are currently becoming a more global than local issue. This paper aims to demonstrate a complex, universal urban water reuse system, allowing for a reduction of freshwater withdrawal. Opportunities for improvement were analyzed in the categories of municipal services: power and heat production, greenery irrigation, landscaping, street and public transport fleet cleaning. Technical possibilities were coupled with current international legislative requirements. Two scenarios for universal, complex water reuse systems in the municipal area were evaluated, including all essential city services. Results of the case study show that ozonation and filtration of treated wastewater should be sufficient to obtain the desired water quality for urban purposes. Current legislation mainly addresses agricultural water reuse, so their requirements should be adjusted to assess the water quality needed for other applications. When water is used in public spaces, constant monitoring for the presence of pathogens should be maintained due to the risk of human exposure. A life cycle assessment was conducted to evaluate the environmental impacts associated with the topic of water transportation in urban areas, which is infrequently considered in such studies. Two scenarios including different means of transport were compared. It was shown that with constant daily operation, it is necessary to build an independent water network, since the environmental impact of water delivery by tank lorries increases substantially.

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Joanna Witkowska‐Dobrev, Olga Szlachetka, Maciej Malarski, Justyna Czajkowska, Maciej Miturski, Piotr Nowak, Marek Dohojda

This paper presents the results of a study on the compressive strength, weight loss, surface roughness, elemental analysis and ultrasonic pulse velocity (UPV) measurement after 270 days of seasoning concrete cubes measuring 100 × 100 × 100 mm in solutions of sewage from the post-grit chamber as well as sewage from the activated sludge chamber in three different environments, that is, acidic, neutral, and alkaline. The value of the compressive strength of the samples stored in the tested environments varied depending on the type of the tested wastewater and its pH in relation to the control sample. The most influence on compressive strength was acidic environment—the decrease was approximately 12.7% in the post-grit chamber and 9.5% in the activated sludge chamber. Samples which had been seasoned in the post-grid chamber were characterized by UPVs ranging from 4805.3 to 4864.6 m/s. Samples seasoned in an activated sludge chamber achieved UPVs ranging from 4689.7 to 4778.9 m/s. The average relative error between the compressive strength values calculated from the ultrasonic method according formula (3) and the measured values does not exceed 4%. The conclusions from the 3D measurements of roughnesses show that parameters Ra, Rz, Sa, and Sq are the most reliable in assessing the roughness intensity of corrosion damage of concrete caused by sewage. Elemental analysis proved that in the acidic pH solution of sewage from the post-grit chamber, the presence of calcium was not identified at any of the points tested.

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Łukasz Pieron, Krzysztof Woś, Krzysztof Wrzosek

Retention reservoirs are one of the basic elements of water management. Multifunctional, they are used for flood protection, drought prevention and other purposes. Water reservoirs can also play a fundamental role in improving navigability on the lower section of the Vistula River from the Włocławek barrage to the mouth of the Gdansk Bay. Their implementation is a determinant for the possibility of restoring the economic role of the river in question. Therefore, the purpose of this research was to determine the current navigation conditions and the state of the regulatory buildings on the Lower Vistula. The investments necessary to achieve international parameters of the waterway were also determined, together with the calculation of financial benefits related to their implementation. This was possible based on the conducted bathymetric measurements, spatial analyses, economic calculations and queries of the obtained studies. It was established that fairway depths of 1.4 m are ensured for 180 days per year on average. On the other hand, the construction of five barrages (Siarzewo, Solec Kujawski, Chełmno, Grudziądz and Gniew) will make it possible to achieve at least a navigability class IV (international) on the section of the Vistula River waterway. In addition, the barrages will enable the retention of 1.2 billion m3 of water and will be associated with financial benefits such as shipping use, flood protection and counteracting the effects of drought. On this account, annual revenues may amount to approximately PLN 3.5 billion. This shows that the construction of the reservoirs is profitable, and the proposed solutions should be implemented in the context of sustainable water management and adaptation to climate change.

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Krzysztof Woś, Radosław Radoń, Tomasz Tekielak, Krzysztof Wrzosek, Łukasz Pieron, Michał Piórecki

Multifunctional flood protection reservoirs of regional importance have been controversial for many years due to their significant environmental impact. The impact is especially observed at the implementation stage. Undeniably, properly managed large water reservoirs are the most effective element of active flood protection and significantly reduce the flood wave, thus limiting losses in housing, infrastructure, industry, or agriculture. At the same time, multifunctional reservoirs pursue other goals that are related to reducing shortages and counteracting the effects of drought, water supply, hydropower, or recreation. In the era of rapidly advancing climate and geopolitical changes, their role seems indispensable when it comes to responsible and coordinated water management in Poland. An open question is how to fully use the potential and to what extent it is possible for the system of reservoirs located on different watercourses to work together in the era of the progressive development of the country resulting in significant changes in land use (sealing large catchment areas) in relation to design assumptions. The article presents an analysis of the work of selected water reservoirs located in the basin of the upper Vistula during the floods that took place in the last decade. On the basis of the obtained conclusions, the authors present recommendations on how to effectively manage the network of reservoirs during a flood while minimizing losses of the water retained in them, which should be used to meet other goals of water management.

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Sylwia Adach, Małgorzata Wojtkowska, Paweł Religa

In Poland, mountain national parks are visited by about 8 million tourists annually. As a result, national parks must have a properly developed infrastructure to accommodate such a large number of people. Tourism development in mountain national parks satisfies the needs of tourist participants and should increase the attractiveness of the area, fit into the cultural concepts of a given region, and promote its development. The research aims to determine the consequences of making mountain national parks available in Poland and determine the factors determining the attractiveness of the protected area and the related tourist burden. Nine mountain national parks located in Poland were selected for the research. An interview was conducted with employees of mountain national parks concerning (a) the tourist burden on the national park, (b) the tourist management of the national park and its surroundings, and (c) the impact of tourist traffic on the natural environment. Parameters characterizing the intensity and spatial character of tourist traffic, tourist management, and the influence of tourist traffic on the natural environment of mountain national parks are discussed. The study presents the parameters determining: tourist traffic density, tourist route density, and tourist traffic intensity. A map of the development of the surroundings of national parks was presented, and its influence on tourist traffic was determined. The obtained results were discussed in the context of the consequences of tourist traffic in mountain national parks. The result of the work was the development of a map of the tourist load of mountain national parks in Poland. Tourism is of crucial importance for the proper functioning of national parks. However, if not properly cultivated, it threatens the fauna and flora of such areas. Rational use of natural resources by tourists visiting mountain national parks is crucial to maintain the balance between man and nature. Proper supervision and management in the national park, as well as the collective responsibility of tourists visiting national parks and the community living in their vicinity, is of fundamental importance for the proper functioning of the system in national parks and nearby tourist destinations.

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Małgorzata Wojtkowska, Karol Wojciech Wojtkowski, Magdalena Długosz-Lisiecka

This research examined samples of mineral water available on the Polish market. The contents of radionuclides in 12 samples of water were determined: cesium 137Cs, thorium 232Th, potassium 40K, and radium 226Ra; and heavy metals: zinc, copper, chromium, nickel, lead, cadmium, and mercury. Spectrometric analysis showed the presence of a 232Th track in one sample (Franciszek water) with a concentration of 2.4 ± 2.1 mBq/L above the LLD (low limit of detection); 40K potassium was detected in all samples. In the case of radium 226Ra, its presence above the detection threshold was found in nine water samples. No artificial element 137Cs was found in the mineral waters. The tests showed the concentrations of heavy metals (Cd, Cr, Cu, Hg, Ni, and Pb) present in the waters. The limit values are specified by the Ministry of Health Regulation. Copper, cadmium, and chromium did not exceed the permissible values. In the case of nickel, the normalized values (20 μg/L) were exceeded in only two waters: Słotwinka and Józefowianka. Only in the Amita water did we find that the value of 1.0 μg/L was exceeded. The concentration of zinc, for which no limit is set in the regulation, was the highest, ranging from 287 to 1.30 μg/L. The greatest threat to people drinking the studied mineral waters is lead, which in eight waters exceeded the permissible value of 10 μg/L.

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Binh Quang Nguyen, Thanh-Nhan-Duc Tran, Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Venkat Lakshmi

In the present day, the acceleration of urban surface heat impacts resulting from urbanization and industrialization is critical for citizens and municipal governments in developing-country cities. The previous key findings have indicated the association between urban surface heat and the following areas: forests, mixed agricultural land, built-up area, and water bodies. This study was motivated by a lack of knowledge regarding the variation of temperature, evaporation, and humidity in Central Vietnam’s major region. The non-parametric Mann–Kendall test, Sen’s slope estimator, and Landsat image analysis were employed to determine the trend and statistical significance of the variables across the 42-year study period for Da Nang city and Quang Nam province. Our results show that Da Nang city has a consistent trend with a high correlation between temperature, evaporation, and relative humidity, whereas Quang Nam province showed an inverse relationship between temperature and relative humidity since the beginning of the regional urbanization. The maximum, minimum, and mean temperatures have increased by at least 0.29 °C in Quang Nam province and 0.71 °C in Da Nang city since 2000. Between 1979 and 2021, the frequency of days with temperatures exceeding 35 °C has increased by two and seven days during the past decade at the meteorological stations in Da Nang and Tam Ky, respectively. The temperature in Da Nang city varied from 31.80 °C to 32.82 °C with high temperatures concentrated in urbanized regions with less coverage of small trees, plants, and water bodies. Thus, the results of this study will serve as a scientific basis for decision-makers and regional officials for land-use management and to increase community awareness of sustainable planning, particularly in Da Nang city and Quang Nam province in Central Vietnam.

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Marcin Wołowicz, Alkasmoul Fahad, Asaker Mohammed, Widuch Aleksander, Marcin Michał Malicki, Ryszard Zwierzchowski

Innovative hybrid source for electricity, cooling and desalinated water production based on a mixed fossil fuel/solar energy supply, equipped with triple-component chiller configuration, has been presented in the paper. The system was erected and recently commissioned in King Abdulaziz City for Science and Technology (KACST) in Kingdom of Saudi Arabia to operate as a working laboratory supplying media to adjacent buildings of the Solar Village complex. In the Arabian Gulf region, increased demand, especially for cooling and desalinated water, as well as fluctuating availability of electricity from the grid in summer period is visible, what makes such a stand-alone installation operation justified especially in remote areas. Abundant availability of intermittent solar energy correlated with cooling demand led to development of novel triple-component chiller configuration consisting of absorption, adsorption and compressor chiller. Two Diesel internal combustion engines had been selected to supply electricity and heating when solar energy is not available. Paper presents results of installation commissioning, during which the performance of the system for three different operating scenarios was assessed. Maximum efficiency was achieved for maximum renewable energy production option reaching 324.91% with renewable share at a level of 89.99%. For the maximum cooling capacity production, the efficiency of the system was 124.89% with 18.6% share of renewable energy. The lowest efficiency, of 93.09%, system obtained for the night scenario.

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Kamil Urbanowicz, Anton Bergant, Michał Stosiak, Adam Deptuła, Mykola Karpenko, Michał Kubrak, Apoloniusz Kodura

Omission of frequency-dependent hydraulic resistance (skin friction) during modelling of the water hammer phenomenon is unacceptable. This resistance plays a major role when the transient liquid flow occurs in rigid-walled pipes (steel, copper, etc.). In the literature, there are at least two different modelling approaches to skin friction. The first group consists of models based on instantaneous changes in local and convective velocity derivatives, and the second group are models based on the convolution integral and full history of the flow. To date, more popular models are those from the first group, but their use requires empirical coefficients. The second group is still undervalued, even if based on good theoretical foundations and does not require any empirical coefficients. This is undoubtedly related to the calculation complexity of the convolution integral. In this work, a new improved effective solution of this integral is further validated, which is characterised with the use of a simplified weighting function consisting of just two exponential terms. This approach speeds the numerical calculations of the basic flow parameters (pressure and velocity) significantly. Presented comparisons of calculations using the new procedure with experimental pressure runs show the usefulness of the proposed solution and prove that it maintains sufficient accuracy.

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Michał Kubrak, Apoloniusz Kodura, Agnieszka Malesińska, Kamil Urbanowicz

This paper experimentally and numerically investigates the water hammer phenomenon in serially connected steel and HDPE pipes with different diameters. The aim of the laboratory tests was to obtain the time history of the pressure head at the downstream end of the pipeline system. Transient tests were conducted on seven different pipeline system configurations. The experimental results show that despite the significantly smaller diameter of the HDPE pipe compared to the steel pipe, introducing an HDPE section makes it possible to suppress the valve-induced pressure surge. By referring to the results of the experimental tests conducted, the comparative numerical calculations were performed using the fixed-grid method of characteristics. To reproduce pressure wave attenuation in a steel pipe, Brunone-Vitkovský instant acceleration-based model of unsteady friction was used. To include the viscoelastic behavior of the HDPE pipe wall, the one-element Kelvin–Voigt model was applied. By calibrating the unsteady friction coefficient and creep parameters, satisfactory agreement between the calculated and observed data was obtained. The calibrated values of parameters for a single experimental test were introduced in a numerical model to simulate the remaining water hammer runs. It was demonstrated that using the same unsteady friction coefficient and creep parameters in slightly different configurations of pipe lengths can be effective. However, this approach fails to reliably reproduce the pressure oscillations in pipeline systems with sections of significantly different lengths.

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Apoloniusz Kodura, Katarzyna Weinerowska-Bords, Michał Kubrak

Rapid transients are particularly dangerous in industrial hydro-transport systems, where solid-liquid mixtures are transported via long pressure pipelines. A mathematical description of such flow is difficult due to the complexity of phenomena and difficulties in determining parameters. The main aim of the study was to examine the influence of the simplified mixture density and wave celerity description on satisfactory reproduction of pressure characteristics during the transient flow of slurry at low concentrations. The paper reports and discusses the selected aspects of experimental and numerical analyses of transient slurry flow in a polyethylene pipe. The experiments were conducted by using the physical model of a slurry’s transportation pressure. The aim of the experiments was to determine the wave celerity during a transient flow in slurries. A low concertation of slurries, which was used during experiments, is typical for one of the biggest slurry networks in Poland. A comparison of the effects of different wave celerity descriptions was performed. The research reported that the theoretical formulas for slurry wave celerity and mixture density were not sufficiently accurate to obtain satisfactory compliance between calculations and observations. To improve the model, the experimental values of wave celerity and the concept of equivalent mixture density have been applied to indirectly consider the influence of variable mixture parameters. With such modifications, the calculated pressure characteristics in all analyzed episodes demonstrated satisfactory compliance with observations. The simplified approach proved to be effective in properly reproducing the intensity and frequency of rapid pressure changes.

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Łukasz Dominik Kaczmarek, Małgorzata Jastrzębska, Tomasz Wejrzanowski

In the field of soil drying methods, rapid microwave heating is progressively replacing conventional techniques. Due to the specific heat transport caused by microwaves, the drying process can significantly modify soil structure, which, in turn, can influence mechanical and filtration characteristics. In this study, we compared structural changes of exemplary non-cohesive (medium quartz sand (MSa)) and cohesive soil (silty clay mainly composed of kaolinite (siCl)). The sample materials were subjected to three different drying methods: air-drying, conventional oven (CO) drying, and microwave oven (MO) drying (MO). Soil structure was studied using X-ray microtomography (XµCT) and described in detail by image analysis methods. The study showed that the analyzed types of heating had a negligible effect on the structure of the sands, but a significant impact in the case of silty clay. Such a phenomenon is discussed and explained in this paper. The study advances the testing of soils microwave drying in a geotechnical laboratory.

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Paweł Gilewski

As the world is changing, mainly due to climate change, extreme events such as floods and droughts are becoming more frequent and severe. Considering this, the predictive modeling of flow in small mountain catchments that are particularly vulnerable to flooding is critical. Rainfall data sources such as rain gauges, meteorological radars, and satellites provide data to the hydrological model with a lag. Only numerical weather predictions can achieve this in advance, but their estimates are often subject to considerable uncertainty. This article aims to verify whether Global Environmental Multiscale numerical precipitation prediction can be successfully applied for event-based rainfall–runoff hydrological modeling. These data were verified for use in two aspects: the flow modeling and determination of antecedent moisture conditions. The results indicate that GEM data can be satisfactorily used for hydrological modeling, and particularly good simulation results are obtained when significant rainfall occurs. In addition, these data can be used to correctly estimate the AMC groups for each sub-catchment in advance, which is one of the key elements flowing into the amount of projected outflow in the catchment. It is worth noting that, according to the literature review conducted by the article’s author, this is the first published attempt to use GEM data directly in applied hydrological applications.

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Artur Jerzy Badyda, Wioletta Rogula-Kozłowska, G Majewski, Karolina Bralewska, Kamila Widziewicz-Rzońca, Barbara Piekarska, Mariusz Rogulski, Jan S. Bihałowicz

The manuscript presents an innovative and holistic approach to quantifying PAHs and BTEX emissions from the grilling process and indicates a novel driven–toxicity-based solution to recognize health effects related to BBQ emissions. The exposure scenario includes the type of grilling device, food type, and individual attitudes, but also a keen understanding of the broad health implications related to the gaseous/particulate PAHs emission, or age-related effects. The calculated incremental lifetime cancer risk (ILCR) associated with the exposure to PAH congeners and BTEX indicates an unacceptable level in the case of charcoal and briquette grilling with the highest values for professional cooks. The sum of 15 PAH concentrations in grilled foods was highest for meat grilling over charcoal briquettes – 382,020.39 ng/m3 and lowest for meat grilling on a gas grill – 1442.16 ng/m3. The emissions of BTEX from lump charcoal grilling were 130 times higher compared to the gaseous grill. In all considered scenarios lump-charcoal and charcoal briquettes grilling derive the ILCR above the 10−4, indicating negative effects of traditional grills on human health. The paper completes knowledge of wide-ranging health implications associated with BBQs, a topic that is almost completely unaddressed among the scientific community and policymakers.

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Martyna Godzieba, Monika Żubrowska-Sudoł, Justyna Walczak, Sławomir Ciesielski

Microorganisms play a key role in biological wastewater treatment. The form in which biomass develops determines the efficiency and mechanisms of organic compound conversion, due to different conditions in various microbial structures. However, the results of studies comparing the microbial communities in biofilm and activated sludge have often conflicted. Therefore, this study compared the composition and development of the bacterial communities in biofilm and activated sludge in a hybrid reactor, employing 16S rRNA sequencing. Statistical analysis of the sequencing data included the identification of taxa characteristic to the biofilm and activated sludge, alpha and beta diversity analysis, and network analysis. These analyses indicated that the biofilm bacterial community was richer and more diverse than the activated sludge community. The mean numbers of OTU were 1614 in the biofilm and 993 in the activated sludge, and the mean values of the Chao1 (1735 vs. 1105) and Shannon (5.3 vs. 4.3) biodiversity indices were significantly higher for the biofilm. The biofilm was a better environment for development of nitrifiers (e.g., NitrosomonasNitrospira) and phosphorus accumulating organisms (Candidatus Accumulibacter). Bacteria in the biofilm co-occurrence network had more connections (based on Spearman’s rank correlation coefficient) with each other, indicating that they interact more than those in the activated sludge.

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Artur Jerzy Badyda, Andrzej Brzeziński, Tomasz Jacek Dybicz, Karolina Magdalena Jesionkiewicz-Niedzińska, Piotr Olszewski, Beata Agnieszka Osińska, Piotr Szagała, Dominika Mucha

During a pandemic, the mobility of people changes significantly from the normal situation (the number of trips made, the directions of travel and the modes of transport used). Changes in mobility depend on the scale of the pandemic threat and the scale of the restrictions introduced and assessing the impact of these changes is not straightforward. This raises the question of the social cost of changes in mobility and their impact on the environment, including air quality. The article shows that it is possible to determine this impact using big data from mobile operators’-SIM card movements and data from air quality monitoring stations. Data on SIM card movements allows for reconstructing the state of the transport system before and during the different phases of a pandemic. The changes in mobility of people determined in this way can be related to the results of measurements of pollutant concentrations in the air. In this way, it is possible to identify links between mobility changes and air quality. The article presents the extent (in relation to the state without the pandemic) of changes in the mobility of the population during the pandemic and the related impact on air quality using the example of Warsaw.

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Marta Wiśniewska, Mirosław Szyłak-Szydłowski

Urbanisation development affects urban vegetation both directly and indirectly. Since this process usually involves a dramatic change in land use, it is seen as likely to cause ecological pressure on local ecosystems. All forms of human activity, including urbanisation of areas close to residential buildings, significantly impact air quality. This study aims to identify and characterise different measurement solutions of VOCs, allowing the quantification of total and selective compounds in a direct at source (in situ) manner. Portable devices for direct testing can generally be divided into detectors, chromatographs, and electronic noses. They differ in parameters such as operating principle, sensitivity, measurement range, response time, and selectivity. Direct research allows us to obtain measurement results in a short time, which is essential from the point of view of immediate reaction in the case of high concentrations of tested compounds and the possibility of ensuring the well-being of people. The paper also attempts to compare solutions and devices available on the market and assess their application.

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Monika Żubrowska-Sudoł, Justyna Walczak, Grzegorz Piechota

The goal of the study was to evaluate the possibility of use of disintegrated excess sludge to enhance combined biological nutrient removal from wastewater. In the experiment lasting 295 days four runs were performed. Effectiveness of contaminants removal in sequencing batch reactor without and with applying sludge subjected previously to hydrodynamic disintegration at three energy density (ƐL) levels was analysed. It was shown that ƐL is a crucial parameters responsible for the characteristics of disintegrated sludge applied as a carbon source for biological nutrient removal. Using sludge disintegrated at 70 and 210 kJ/L the increase in effectiveness of N and P removal was noted, averagely by 16.1 % (N removal) and 70.3 % (P removal) at ƐL = 70 kJ/L and by 17.8 % and 63.1 % at ƐL = 210 kJ/L. On the contrary, use of sludge disintegrated at ƐL = 280 kJ/L caused decline in N removal by averagely 12.8 %, what was a consequence of nitrification failure.

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Małgorzata Wojtkowska, Agnieszka Malesińska, Agnieszka Machowska, Pierfabrizio Puntorieri, Giuseppe Barbaro, Vincenzo Fiamma, Stanisław Biedugnis

The article presents the results of an investigation of water composition and quality in sprinkler installations, as well as the influence of temperature changes on the corrosion process. The physical and chemical components of the water were measured to ascertain the influence of its properties on the corrosion process in a wet pipe sprinkler system operating in significantly changing ambient temperature conditions. The article presents the results of measurements of the wall thickness of galvanized pipes and changes in the chemical composition of water occurring under the influence of variable ambient temperature. The range and variability of temperatures corresponded to the seasons of the year: spring and summer in a temperate climate. Changes in the corrosive aggressiveness of water were assessed using the Langelier saturation index (LSI), the Ryznar stability index (RSI), and the general acidity intensity index (I). The tests revealed that the tap water used demonstrated strong corrosive properties for galvanized pipes. The calculated indices showed the tendency of water to cause corrosion (−1.1 > LSI < 1.0; RSI = 7.1–12.8). The chemical parameters that significantly influenced the corrosion of galvanized pipes are chloride (Cl), sulphate (SO42−), and bicarbonate (HCO3−) ions. An important factor contributing to the intensification of corrosion is the roughness and heterogeneity of the pipe surface.

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Maria Grodzka-Łukaszewska, Grzegorz Igor Sinicyn, Mateusz Grygoruk, Dorota Mirosław-Świątek, Ignacy Kardel, Tomasz Okruszko

Study region. The area of interest is the Upper Biebrza Valley, located in NE Poland. Study focus. We examined water exchange at the river-fen interface in a near-natural wetland system using the combined field research-modeling approach. The authors chose the Biebrza River as the research object: it is a specific case of fen marginal valley rivers, and it flows in the peat layer without direct connection to the mineral soil layer. Our case study introduces two new aspects not yet considered in the scientific literature: (1) the riparian aquifer is fen and (2) the river has no direct contact with the mineral layer. The following research questions were investigated: What is the role of the river in feeding and draining a fen? Which drainage paths are important for water exchange in a near-natural river-fen system? How important are the morphological settings for the river-fen relations? We applied a systematic hydrological research approach based on field measurements and observations of the river and surrounding fen hydrological characteristics, as well as on the modelling results. New hydrological insights for the region. We demonstrated that morphological settings have a significant influence on river-fen relations. We also demonstrated that due to the undeniable need to introduce increased protection and restoration of marginal fens, we may focus on river status in narrow valleys; however, in the wide valleys, the limitation of the drainage layer by decreasing the intensity of evapotranspiration is more promising. We propose to distinguish zones in the fen river valley to include them when proposing protection or conservation plans.

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Małgorzata Wojtkowska, Jan Bogacki

The impact of the ethylenediaminetetraacetic acid (EDTA) on speciation image of selected trace metals (Zn, Cd, Cu, Pb) in bottom sediments was determined. The influence on the effectiveness of metal removal of extraction multiplicity, type of metal, extraction time and concentration of EDTA were analyzed. With the increase of extraction multiplicity, the concentration of EDTA and contact time, the efficiency of trace metals leaching increased. The speciation analysis revealed that EDTA not only leached metals from bioavailable fractions, but also caused the transition of the metals between the fractions. The biggest amounts of bioavailable forms were found for Cd, less for Zn. The amount of bioavailable fraction was the lowest for Cu and Pb. The two first-order kinetic models fitted well the kinetics of metals extraction with EDTA, allowing the metals fractionation into “labile” (Q1), “moderately labile” (Q2) and “not extractable” fractions (Q3).

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Andrzej Kulig, Mirosław Szyłak-Szydłowski, Marta Wiśniewska

Odorant emissions are associated with, among other things, wastewater transport in sewer networks; they contribute to air pollution and result in complaints from residents living close to emission sources. The critical location in terms of the formation of unpleasant odour compounds is the pressure line that connects the pumping station and the expansion well; this is where they are released into the atmosphere. This paper presents comprehensive results of olfactometric and chromatographic tests in the Polish city of Białystok using portable devices that allow for multiple determinations and instant results. The study attempts to investigate the relationship between odour and odorant concentrations and check the suitability of field olfactometry as a tool for the ongoing monitoring of the emission of noxious odours and for verifying complaints submitted by residents. Statistical analysis shows a very high correlation coefficient between cod and the concentrations of individual odorants, ranging from 0.82 to 0.91. This olfactometric research, mainly conducted in situ, can be an appropriate method for the ad hoc monitoring of processes in sewage networks. This method allows the detection of unwanted emissions of odours at individual points in the network in concentrations that are not detected by standard sensors but that nevertheless cause odour nuisances, complaints, and social conflict. The research results provide evidence in favour of the energetic usage of wastewater, which is in line with circular economy conception, since odour nuisance is one of its indicators.

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Paweł Falaciński, Łukasz Szarek

In recent years, there has been a marked increase in the amount of municipal waste generated in Poland. In the context of circular economy assumptions, the key is the availability of technologies that would make it possible to safely process and reuse waste, especially when it is difficult to manage. One such direction is thermal waste treatment. In 2020, 21.6% of all municipal waste was subjected to this process. Consequently, the amount of ash generated is significant (approximately 2,823,000 tons annually). One of the uses of waste materials is the sealing of earth hydrotechnical facilities, such as flood embankments, water dams, and embankments of waste landfills. For this purpose, cut-off screens made of hardening slurries are used. In order to improve the tightness and corrosion resistance of hardening suspensions, combustion by-products are added to their composition. The article presents an assessment of the possibility of using ashes from municipal waste incineration as an additive to hardening slurries. It also discusses the technological and operational parameters of hardening slurries with the addition of the ashes in question. Binding requirements for hardening slurries used for the construction of cut-off walls is also defined. The experiment showed that the tested hardening slurries meet most of the suitability criteria. Further research directions are proposed to fully identify other properties of hardening slurries in terms of their environmental impact.

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Piotr Dąbrowiecki, Andrzej Chciałowski, Agata Dąbrowiecka, Artur Jerzy Badyda

Ambient air pollution in urban areas may trigger asthma exacerbations. We carried out a time-series analysis of the association between the concentrations of various air pollutants and the risk of hospital admission due to asthma over 7 days from exposure. We used distributed lag nonlinear models to analyze data gathered between 2010 and 2018 in the three largest urban agglomerations in Poland. Overall, there were 31,919 asthma hospitalizations. Over 7 days since exposure, the rate ratio (95%CI) for admission per 10 µg/m3 was 1.013 (1.002–1.024) for PM10; 1.014 (1.000–1.028) for PM2.5; 1.054 (1.031–1.078) for NO2; and 1.044 for SO2 (95%CI: 0.986–1.104). For all pollutants, the risk of admission was the greatest on the day of exposure (day 0), decreased below baseline on days 1 and 2, and then increased gradually up to day 6. The proportions (95%CI) of hospitalizations attributable to air pollution were 4.52% (0.80%–8.14%) for PM10; 3.74% (0.29%–7.11%) for PM2.5; 16.4% (10.0%–21.8%) for NO2; and 2.50% (−0.75%–5.36%) for SO2. In conclusion, PM2.5, PM10, NO2, and SO2 pollution was associated with an increased risk of hospital admission due to asthma in the three largest urban agglomerations in Poland over nine years.

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Małgorzata Loga, Mikołaj Pniewski, Paweł Marcinkowski

Uncertain results of the status assessment performed as required by the Water Framework Directive can be responsible for misclassification of a water body’s status and may lead either to risk due to undertaking unnecessary remediation actions or risk of penalties for refraining from any action and not reaching environmental goals. Based on Bayesian decision theory, optimal decision tables are shown for two examples of water quality indicators, for a river catchment in central Poland. To overcome the problem of scarcity of publicly available monitoring data, the existing SWAT model for the studied catchment was used to generate nutrient concentration time series for the baseline conditions and under different scenarios. The status classes assessed based on annual mean concentrations of daily values for total phosphorus and total nitrogen were adopted as the ‘true’ status classes of the water bodies based on each indicator. SWAT simulation results enabled calculation of probability distributions of concentrations for the stochastic states of the water body, both for the period before and after the performance of corrective actions.

Bayesian decision tables consisted of alternative management decisions including modernization of the existing wastewater treatment plants in the case of phosphorous and also of fallowing agricultural areas in the case of nitrogen. An example of a penalty calculation procedure is presented in the event that the subject of the case before the EU Court of Justice would be failure to achieve the environmental objectives by all water bodies belonging to the selected catchment.

Detailed discussion of this analysis indicates the potential benefits in terms of minimization of costs/losses that the proposed methodology may bring to the protection of surface waters.

The presented method of risk analysis for making decisions on remedial actions when uncertainty exists about the water status assessment, can be considered as a prototype of a general methodology prepared for implementation in water protection. Unfortunately paying fines instead of taking remediation measures might be optimal for uncertain status of water bodies.

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Mariusz Rogulski, Artur Jerzy Badyda, Anna Gayer, Johnny Reis

Conventional NO2 monitoring devices are relatively cumbersome, expensive, and have a relatively high-power consumption that limits their use to fixed sites. On the other hand, they offer high-quality measurements. In contrast, the low-cost NO2 sensors offer greater flexibility, are smaller, and allow greater coverage of the area with the measuring devices. However, their disadvantage is much lower accuracy. The main goal of this study was to investigate the measurement data quality of NO2-B43F Alphasense sensors. The measurement performance analysis of Alphasense NO2-B43F sensors was conducted in two research areas in Poland. Sensors were placed near fixed, professional air quality monitoring stations, carrying out measurements based on reference methods, in the following periods: July–November, and December–May. Results of the study show that without using sophisticated correction methods, the range of measured air pollution concentrations may be greater than their actual values in ambient air—measured in the field by fixed stations. In the case of summer months (with air temperature over 30 °C), the long-term mean absolute percentage error was over 150% and the sensors, using the methods recommended by the manufacturer, in the case of high temperatures could even show negative values. After applying the mathematical correction functions proposed in this article, it was possible to significantly reduce long-term errors (to 40–70% per month, regardless of the location of the measurements) and eliminate negative measurement values. The proposed method is based on the recalculation of the raw measurement, air temperature, and air RH and does not require the use of extensive analytical tools.

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Edwin Koźniewski, Beata Sadowska, Karolina Banaszak

Many factors affect energy demand, and knowing their impact is very important for being able to design a low-energy building. In this group of factors, there are those that cannot be changed and improved after the building is constructed, so taking them into account when choosing a project is important for energy savings. This group includes geometric parameters. We propose a geometric method of assessing the energy demand of a single-family house. The idea is to predict the level of energy demand by calculating the values of simple geometric parameters in the first stage of design. Based on the analysis of 30 realistically designed single-family houses, we show that the geometric indicators expressed by the base area Af, and perimeter P at a fixed building wall height h, perfectly characterize the amount of energy, both usable and final. Moreover, we show linear relationships between the nominated A/V and non-nominated EWA/FA, RCcd compactness ratios. This relationship allows one indicator to be measured with another. As a result, we show how a designer can use a simple calculated index RCcd to find out the level of energy demand.

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Morten Kam Dahl Dueholm, Marta Nierychlo, Kasper Skytte Andersen, Vibeke Rudkjøbing, Simon Knutsson, Sonia Arriaga, Rune Bakke, Nico Boon, Faizal Bux, Magnus Christensson, Adeline Seak May Chua, Thomas P. Curtis, Eddie Cytryn, Leonardo Erijman, Claudia Etchebehere, Despo Fatta-Kassinos, Dominic Frigon, Maria Carolina Garcia-Chaves, April Z. Gu, Harald Horn, David Jenkins, Norbert Kreuzinger, Sheena Kumari, Ana Lanham, Yingyu Law, TorOve Leiknes, Eberhard Morgenroth, Adam Muszyński, Steve Petrovski, Maite Pijuan, Suraj Babu Pillai, Maria A. M. Reis, Qi Rong, Simona Rossetti, Robert Seviour, Nick Tooker, Pirjo Vainio, Mark van Loosdrecht, R. Vikraman, Jiří Wanner, David Weissbrodt, Xianghua Wen, Tong Zhang, Mads Albertsen, P. Nielsen

Microbial communities are responsible for biological wastewater treatment, but our knowledge of their diversity and function is still poor. Here, we sequence more than 5 million high-quality, full-length 16S rRNA gene sequences from 740 wastewater treatment plants (WWTPs) across the world and use the sequences to construct the ‘MiDAS 4’ database. MiDAS 4 is an amplicon sequence variant resolved, full-length 16S rRNA gene reference database with a comprehensive taxonomy from domain to species level for all sequences. We use an independent dataset (269 WWTPs) to show that MiDAS 4, compared to commonly used universal reference databases, provides a better coverage for WWTP bacteria and an improved rate of genus and species level classification. Taking advantage of MiDAS 4, we carry out an amplicon-based, global-scale microbial community profiling of activated sludge plants using two common sets of primers targeting regions of the 16S rRNA gene, revealing how environmental conditions and biogeography shape the activated sludge microbiota. We also identify core and conditionally rare or abundant taxa, encompassing 966 genera and 1530 species that represent approximately 80% and 50% of the accumulated read abundance, respectively. Finally, we show that for well-studied functional guilds, such as nitrifiers or polyphosphate-accumulating organisms, the same genera are prevalent worldwide, with only a few abundant species in each genus.

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Małgorzata Anna Kucharska, SeyedKeyvan Mirehbar, Joanna Agnieszka Ładyńska

Traditional wastewater treatment methods are often insufficient in the case of mature landfill leachate. Therefore novel methods are in demand. Recently, internal microelectrolysis (IME) has been recognized as an effective method besides AOPs for refractory wastewaters treatment. This study investigated the efficiency of a novel combined three-step process (IME-O3/OH􀀀 /H2O2) applied to mature landfill leachate treatment. Waste iron chips and granulated activated carbon (GAC) from nut shells were used in the process. Ozone was applied in doses from 0.28 to 1.4 g/dm3, and the mass ratios of COD/H2O2 were as follows: 1/0, 1/0.5, 1/1 1/1.5, and 1/2. Results showed that the PC is a reasonable pretreatment process before IME. However, COD and TOC removal was up to 22.4% and 37.9%, respectively. It required no additional reagents (before IME acidification is needed). The best total COD removal in the IME process was for Fe/GAC ratio 20/80 g/g in 1 dm3 (76.7%). Studies on the sorption process on GAC showed a significant share in the IME process – 11.2–62.6% of total COD removal. That was an important observation since most other authors ignored the fact of sorption. For optimal parameters of the O3/OH􀀀 /H2O2, total COD removal was 95.4%. The values of TOC, absorbance UV254, and color were highly reduced by 91.2%, 94.7%, and 98.2%, respectively. Additionally, biodegradability has been significantly improved up to 0.36.

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Paweł Popielski, Adam Kasprzak, Bartosz Bednarz

Numerical modelling using Finite Element Method (FEM) is currently a standard procedure for engineering complex structures and determining structure–subsoil cooperation conditions. It is used for, among others, forecasting displacements, which are the calculation results most easily verified. Numerical modelling is also used to identify the impact on neighbouring structures and design a monitoring system and determine expected values, e.g., displacements. A numerical model enables one to optimally design the monitoring system for a facility under construction and the neighbouring structures through selecting a measurement technology, matching the scope of obtained results or choosing sensor and measurement point locations. The implemented monitoring may be based on various technologies, from thermal monitoring, laser scanning, fibre optic measurements, to classic surveying measurements. The walls must protect the soil from excessive displacement and protect the excavation against groundwater inflow. If the wall is not watertight, deepening the excavation may cause a sudden water inflow. Leak and erosion process thermal monitoring is a proven leak detection method. It is based on the tests utilizing heat and water transfer process relations, which are coupled processes. Another tool for verifying numerical models is the installation of DFOS (Distributed Fibre Optic Sensors) at the stage of executing structural elements (e.g., diaphragm walls, barrettes, foundation slab). It allows one to permanently monitor both temperature and displacements during element execution (concrete curing), and following facility construction and operation stages. The paper presents methods for designing selected monitoring elements of engineering objects, based on calculations using the Finite Element Method. The verification of numerical models, based on data obtained from DFOS, classic surveying measurements and thermal monitoring, is also presented.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafin

Technological processes associated with municipal solid waste (MSW) processing are a potential source of odorant emissions, i.e., substances that cause negative olfactory impressions. When released into the atmosphere, these substances can cause odour nuisance complaints from residents. Many scientists have noted the strong relationship between odorant emission sources and odour concentrations and their significant impact on the living comfort of residents near these sources, as well as their social and economic relations. This paper attempts to estimate the odour load of selected elements of the technological sequence of a biogas plant processing municipal waste. Odour load was characterised by four constituents: odorant emissions, odour emissions, the variability of these emissions, and the emission levels per 1 Mg (1000 kg) of waste. The highest odour emissions accompany the storage of mixed MSW, which is associated with a large amount of waste. Limiting the storage time of waste should be an indispensable part of the technological regime. The dominant odorant associated with mixed MSW storage is NH3 emissions. The greatest variability of odorant and odour emissions concerns gases captured from selectively collected waste plastics and metals, due to the varied forms of selective waste collection in the service area, and their unstable efficiency. High variability of NH3 and odour emissions also accompanies digestate dewatering.

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Dominika Ścieżyńska, Dominika Bury, Piotr Marcinowski, Jan Bogacki, Michał Jakubczak, Agnieszka Jastrzębska

Two-dimensional compounds with nanostructural features are attracting attention from researchers worldwide. Their multitude of applications in various fields and vast potential for future technology advancements are successively increasing the research progress. Wastewater treatment and preventing dangerous substances from entering the environment have become important aspects due to the increasing environmental awareness, and increasing consumer demands have resulted in the appearance of new, often nonbiodegradable compounds. In this review, we focus on using the most promising 2D materials, such as MXenes, Bi2WO6, and MOFs, as catalysts in the modification of the Fenton process to degrade nonbiodegradable compounds. We analyze the efficiency of the process, its toxicity, previous environmental applications, and the stability and reusability of the catalyst. We also discuss the catalyst’s mechanisms of action. Collectively, this work provides insight into the possibility of implementing 2D material-based catalysts for industrial and urban wastewater treatment.

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P.O. Czechowski, Konstancja Piksa, Piotr Dąbrowiecki, Aneta I. Oniszczuk-Jarząbek, Ernest Czermański, Tomasz Owczarek, Artur Jerzy Badyda, Giuseppe T. Cirella

This paper examines the relationship between the presence of air pollution and incidence of selected respiratory diseases in the urban population of the Tri-City agglomeration. The study takes into consideration the specific character of the region, relating to coastal, and port-based shipping. Three research hypotheses formulated the study. General regression models were used to identify the health effects of air pollution and developed health costs were calculated in relation to the treatment of diseases. The findings have shown that air pollution and climatic conditions in the Tri-City aggravate the symptoms of bronchial asthma, while also increasing the number of cases of exacerbated chronic obstructive pulmonary disease and pneumonia. The evidence demonstrates the negative impact of shipping on the health condition of the inhabitants. The calculations have shown the extent of financial losses incurred in connection with the treatment of diseases found to have been caused by air pollution. The estimated health costs turned out to be significant for each of the examined diseases. The financial inefficiency of the Polish health care system has also been demonstrated. All the models have been identified for monthly data for the first time.

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Paweł Bury, Michał Stosiak, Kamil Urbanowicz, Apoloniusz Kodura, Michał Kubrak, Agnieszka Malesińska

This paper concerns the start-up process of a hydrostatic transmission with a fixed displacement pump, with particular emphasis on dynamic surplus pressure. A numerically controlled transmission using a proportional directional valve was analysed by simulation and experimental verification. The transmission is controlled by the throttle method, and the variable resistance is the throttling gap of the proportional spool valve. A mathematical description of the gear start-up process was obtained using a lumped-parameters model based on ordinary differential equations. The proportional spool valve was described using a modified model, which significantly improved the performance of the model in the closed-loop control process. After assuming the initial conditions and parameterization of the equation coefficients, a simulation of the transition start-up was performed in the MATLAB–Simulink environment. Simulations and experimental studies were carried out for control signals of various shapes and for various feedback from the hydraulic system. The pressure at the pump discharge port and the inlet port of the hydraulic motor, as well as the rotational speed of the hydraulic motor, were analysed in detail as functions of time. In the experimental verification, complete measuring lines for pressure, speed of the hydraulic motor, flow rate, and temperature of the working liquid were used.

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Lech Gawuć, Lech Łobocki, Joanna Strużewska

This study explores the possibility of estimation of the sensible surface heat flux using satellite-derived surface temperature and road pavement temperature together with in-situ wind and air temperature measurements by the profile method. A 10-year series of data from the roadside weather observation network was used. This dataset contained wind (measured at 5.8–9.5 m above ground) and air temperature (measured at 2.6–4.8 m) together with road surface temperature. Another dataset consisted of 254 simultaneous MODIS observations. A high correlation (0.94) of the surface temperature measured by both methods was noted despite coarse pixel size. We considered satellite-derived surface temperature to determine the sensible heat flux by the profile method; these results were compared to the values obtained using road temperature measured by pavement-mounted sensors. While the overall correlation is relatively strong (0.70) and considerable systematic differences exist, the values of heat flux calculated at different locations show a high spatial coherence – either when using the in situ pavement temperature (correlation ranging from 0.84 to 0.94 for daytime and 0.63–0.84 for nighttime) or the satellite-derived temperature (correlation coefficient 0.72). In most cases, differences between the two flux estimates can be linked to local factors such as the land use structure.

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Krzysztof Woś, Krzysztof Wrzosek, Tomasz Kolerski

Based on new policies of the European Union, green technologies are to be mostly considered for power generation. Hydropower generation is one of the essential elements of sustainable energy production. Therefore, specific attention, both economically and technically, needs to be given to this sector of energy production. The Vistula River in Poland is considered an international waterway. The power production potential of the river has been taken into account over the years. However, further configurations are needed to obtain a more in-depth ecological knowledge-base and economic plans, which are socially approved. In an attempt to make the project environmentally friendly, specific attention was put into sustainable transport. Different methods of transport were researched to find the most renewable transport combination, mainly based on waterways. Having performed a cost–benefit analysis related to the economic aspects of the project, it was found that such an investment is highly profitable (B/C = 2.81).

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Jarosław Biegowski, Małgorzata Robakiewicz, Krzysztof Woś, Krzysztof Wrzosek

Construction of the Włocławek Barrage on the Vistula River in 1970 became an important source of energy; however, it discontinued sediment transport in the Vistula River. This phenomenon resulted in accumulation before and erosion below the barrage; a similar problem can be expected due to the planned construction of the Lower Vistula Cascade. This study is dedicated to finding an effective and feasible solution to sediment transport management, acceptable to a wide group of users (e.g., navigation, energy producers, and ecologists). A numerical 1D model was applied to carry out analysis of hydrodynamics and sediment transport in the river section from Włocławek Barrage to the Vistula River mouth in the Baltic Sea. For calibration, historical data describing the accumulation and erosion created by the Włocławek Barrage were used. The proposed model allowed incorporation of new barrages chronologically, in accordance with the proposed time schedules. Analysis was carried out in a 50-year horizon, using a set of historical flow data. For sediment flushing, it was proposed to use natural flooding events exceeding Q10% discharge and to control sediment management of the adjacent barrages. To use this method in practice requires verification.

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Dominika Ćwiklińska, Anna Bogdan, Mirosław Szyłak-Szydłowski

Operating theatres are very demanding environments that should provide a safe and comfortable indoor environment for the patient and medical staff and, above all, minimize the risk of cross-infection among patients. Patient safety and health are a priority, and these factors are impacted by surgeons. The present study aimed to analyse surgeons’ perceptions of the indoor environment in Polish operating rooms, including the acceptability of the conditions and their perceptions of workload capacity.

The results of our study demonstrate that 86.1% of physicians found the thermal environment uncomfortable, 62.7% found the noise in the operating room uncomfortable, and 62.7% found the lighting in operating rooms uncomfortable. During the procedure, for 69.7% of respondents, the smell in the operating room was perceptible, but for 70.3%, it was acceptable. The greatest discomfort associated with clothing is its impermeability, which leads to discomfort in an overly warm environment. The study showed that the environment of operating rooms is very important due to the confirmed difficulties in Polish operating rooms and that the scope of research should be broadened to improve the environmental conditions, which will reduce the difficulty of work for medical staff.

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Paweł Ogrodnik, Gabriela Rutkowska, Jacek Szulej, Mariusz Żółtowski, Aleksandra Powęzka, Artur Jerzy Badyda

The aim of research was an influence evaluation of fly ash and zeolite on selected parameters of cement mortar. The scope of the research includes studies of composition and properties of fly ash itself from the thermal transformation of sewage sludge and natural zeolite (clinoptilolite). The research also included the determination of selected mechanical properties of designed mortars, both under normal conditions and after initial thermal loads. A mortar was designed based on CEM I 42.5 R Portland cement with different content of the applied additive in the amount of 5, 10 and 15% of the cement weight. In the course of experimental work, the bending strength of mortars heated at 20, 300, 500, 700 °C were tested. The resulting beam halves (40 × 40 × 160 mm) were used to test the compressive strength. The collected results made it possible to compare the properties of the mortars. The experiment confirmed the possibility of producing cement mortars modified with fly ash from thermal transformation of sewage sludge and zeolite from tuff deposits. The average compressive strength for the mortar containing 5% fly ash and zeolite was set at 28.7 and 27.1 MPa, respectively.

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Łukasz Adamkiewicz, Katarzyna Maciejewska, Daniel Rabczenko, Anetta Drzeniecka-Osiadacz

A strong and consistent association has been observed between morbidity or mortality rates and PM concentration, and is well documented in many countries. In Poland, despite poor air quality, studies concerning the evaluation of acute health effects of ambient air pollution on morbidity from respiratory or cardiovascular diseases are rare. We examined the short-term impact of PMx concentration on hospital admission in 31 Polish cities based on the daily PM10, PM2.5 concentration, meteorological variables, and hospital data. The generalized additive model (GAM) and a random-effects meta-analysis were used to assess the impact of air pollution on morbidity within the exposed population. Almost 1.6 million cardiovascular admissions and 600 thousand respiratory disorders were analyzed. The RR values for PM10-related cardiovascular and respiratory hospital admissions in Poland are equal to 1.0077 (95% confidence interval, 1.0062 to 1.0092) and 1.0218 (95% confidence interval, 1.0182 to 1.0253), respectively, while for PM2.5 1.0088 (95% confidence interval, 1.0072 to 1.0103) and 1.0289 (95% confidence interval, 1.0244 to 1.0335), respectively. Moreover, a moderate heterogeneity of RR estimates was observed between the analyzed cities (I2 values from 27% to 45%). The presented analysis confirms the significant association between hospital admission and PMx concentration, especially during heating seasons.

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Karolina Bralewska, Wioletta Rogula-Kozłowska, Dominika Mucha, Artur Jerzy Badyda, Magdalena Kostrzon, Adrian Bralewski, Stanisław Biedugnis

This study aimed to evaluate the mass concentration of size-resolved (PM1, PM2.5, PM4, PM10, PM100) particulate matter (PM) in the Wieliczka Salt Mine located in southern Poland, compare them with the concentrations of the same PM fractions in the atmospheric air, and estimate the dose of dry salt aerosol inhaled by the mine visitors. Measurements were conducted for 2 h a day, simultaneously inside (tourist route, passage to the health resort, health resort) and outside the mine (duty-room), for three days in the summer of 2017 using DustTrak DRX devices (optical method). The highest average PM concentrations were recorded on the tourist route (54–81 µg/m3), while the lowest was in the passage to the health resort (49–62 µg/m3). At the same time, the mean outdoor PM concentrations were 14–20 µg/m3. Fine particles constituting the majority of PM mass (68–80%) in the mine originated from internal sources, while the presence of coarse particles was associated with tourist traffic. High PM deposition factors in the respiratory tract of children and adults estimated for particular mine chambers (0.58–0.70), the predominance of respirable particles in PM mass, and the high content of NaCl in PM composition indicate high health benefits for mine visitors.

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Anna Bogdan, Kacper Ogłodziński, Mirosław Szyłak-Szydłowski

Thermal plumes generated by a human being are elements that influence the shape of air flows in a room, mainly when displacement ventilation is used. The characteristics of the airflow in these plumes are usually studied using thermal manikins, which has many advantages during the research of thermal man-environment interactions––owing to the repeatability of tests, lack of fatigue, or taking into account individual human characteristics. However, under actual conditions, thermal plumes are generated by real people, who may move slightly, breathe, and have different body surface shapes and thermoregulatory system reactions. Therefore, this study aimed to evaluate the thermal plumes formed over human subjects in an environment typical of office spaces. The study was carried out under conditions of a moderate environment, with men of similar body build, wearing clothes with similar heat insulation, and in a sitting position. The study confirmed that when simulating this process with thermal manikins, it is necessary to get as close as possible to the conditions in which the future occupants of the rooms will be in––as the air velocity values measured over the volunteers are generally lower than the air velocities measured in the study using thermal manikins. It is also necessary to start the thermal manikin breathing process; however, this should be conducted carefully. This significantly affects the obtained results of the air velocity in the thermal plumes and may generate overestimated results.

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Ferdinand Uilhoorn

The sensor location and selection of model noise parameters play an utmost important role in the performance of data assimilation methods. Suboptimal sensor placement may lead to incomplete information and incorrectly chosen noise parameters can cause filter divergence. Till now, these issues were addressed separately, but in this work, we consider both. We present an algorithm that finds the optimal sensor location and non-Gaussian model noise parameters not only separately but also simultaneously. The optimal location was determined for a fixed number of sensors and the root mean square error was used to assess the accuracy of the data assimilation scheme. A direct search method was implemented and, due to the stochastic nature of the filtering method, we used a sample average approximation approach. To prove the usefulness of the algorithm, we selected Riemann problems in one and two dimensions, where the solutions contain shock waves, rarefaction waves, and contact discontinuities. A high order finite volume weighted essentially non-oscillatory scheme was used for the numerical approximation. We used the Rusanov Riemann solver for the numerical flux and the three-stage third-order strong stability preserving Runge-Kutta scheme for the time advancing. Numerical experiments showed that optimizing both sensor location and model noise parameters gives more accurate results without suffering from filter divergence. Uniform distribution of the sensors and manually setting the noise parameters caused the filter to fail to track the truth, especially near the discontinuities.

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Monika Żubrowska-Sudoł, Katarzyna Sytek-Szmeichel, Piotr Krawczyk, Agnieszka Bisak

This study aimed to evaluate the effects of mechanical disintegration of waste activated sludge (WAS) on full scale anaerobic digestion, considering the possibility of obtaining a positive energy balance. The results showed that an increase in energy density (εL) used in disintegration was accompanied by an increase in the release of organic compounds from sludge (SCOD increased from 211 ± 125 mg O2/L for εL = 0 kJ/L to 6292 ± 2860 mgO2/L for εL = 180 kJ/L). Some of them were volatile fatty acids. The percentage share of WAS subject to disintegration was also documented as a crucial parameter affecting the efficiency of biogas production. An increase in the value of this parameter from 25% to 100%, even at much lower εL used in disintegration (therefore with much smaller amounts of organic compounds released from sludge flocs) resulted in an increase in biogas production. Conducting disintegration of the entire stream of WAS directed to the fermentation tank at εL 30 kJ/L resulted in an increase in biogas production by 14.1%. Such a surplus would allow production of approximately 360 kWh/d net electricity. Mechanical disintegration of thickened WAS therefore may be an economically justifiable strategy for the intensification of anaerobic sludge stabilisation.

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Andrzej J. Osiadacz, Marta Gburzyńska

The main aim of simulation programs is to study the behavior of gas pipe networks in certain conditions. Solving a specified set of differential equations describing transient (unsteady) flow in a gas pipeline for the adopted parameters of load and supply will help us find out the value of pressure or flow rate at selected points or along selected sections of the network. Transient gas flow may be described by a set of simple or partial differential equations classified as hyperbolic or parabolic. Derivation of the mathematical model of transient gas flow involves certain simplifications, of which one-dimensional flow is most important. It is very important to determine the conditions of pipeline/transmission network operation in which the hyperbolic model and the parabolic model, respectively, should be used. Parabolic models can be solved numerically in a much simpler way and can be used to design simulation programs which allow us to calculate the network of any structure and any number of non-pipe elements. In some conditions, however, they describe the changes occurring in the network less accurately than hyperbolic models do. The need for analysis, control, and optimization of gas flows in high-pressure gas pipelines with complex structure increases significantly. Very often, the time allowed for analysis and making operational decisions is limited. Therefore, efficient models of unsteady gas flows and high-speed algorithms are essential.

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Olga Zając, Monika Żubrowska-Sudoł, Slawomir Ciesielski, Martyna Godzieba

The purpose of the study was to analyse the impact of aeration strategies defined by the changes in the duration of aerated sub-phases, the ratio between non-aerated and aerated sub-phase times (R), and dissolved oxygen concentrations (DO) on the suppression of nitrite-oxidizing bacteria (NOB) in activated sludge and biofilm developing in a hybrid reactor with nitrification/denitrification. The primary factor causing NOB suppression both in biofilm and in activated sludge was an increase in the R-value (from 0 to 1/4 and from 1/4 to 1/3). After reducing the DO from 3 to 2 mg O2/L, there were no changes in the frequency of NOB occurrence, and no reduction in the nitrite oxidation rate was recorded. The abundance of Comammox bacteria was considerably affected by the change from continuous to intermittent aeration. Activated sludge showed a substantial increase in the quantity of clade A and B, whereas the quantity considerably decreased in biofilm.

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Ryszard Zwierzchowski, Olgierd Niemyjski, Marcin Wołowicz

The paper presents an analytical discussion of how to improve the energy efficiency of the steam cushion system operation for a Thermal Energy Storage (TES) tank. The EU’s green deal 2050 target policy requires an increase in the energy efficiency of energy production and use, as well as an increase in the share of renewable energy in the overall energy production balance. The use of energy-efficient TES is considered as one of the most important technologies to achieve the objectives of this EU policy. The analyses presented in the paper of energy-efficient operation of steam cushion (SC) systems were carried out by using operational data received from three District Heating Systems (DHSs) that supply heat and electricity to one of the largest cities in Poland and are equipped with the TES systems. These three analyzed TESs differ in capacities from 12,800 to 30,400 m3, tank diameters from 21 to 30 m and shell height from 37 to 48.2 m. The main purpose of using a steam cushion system in the TES tank is to protect the water stored in it against the absorption of oxygen from the surrounding atmospheric air through the surge chamber and safety valves located on the roof of the tank. The technical solutions presented here for the upper orifice for charging and discharging hot water into/from the tank and the suction pipe for circulating water allow to us achieve significant energy savings in the steam cushion systems. Both the upper orifice and the end of suction pipe are movable through the use of pontoons. Thanks to the use of this technical solution, a stable insulating water layer is created above the upper orifice in the upper part of the TES tank, where convective and turbulent transport of heat from the steam cushion space to the hot water stored in the tank is significantly limited. Ultimately, this reduces the heat flux by approximately 90% when compared to the classic technical solutions of steam cushion systems in TES tanks, i.e., for the upper orifice and circulation water pipe. The simplified analysis presented in the paper and comparison of its results with experimental data for heat flow from the steam cushion space to hot water stored in the upper part of the TES tank fully confirms the usefulness of the heat-flow models used.

Arkadiusz Węglarz, Paweł Grzegorz Gilewski

Buildings in Poland are still constructed using technologies and methods created decades ago, even though many new technologies can be applied. Such an approach in the construction process is not sufficient to ensure the sustainable development of the world. Therefore, there is a great need for implementing new, innovative technical, economic, and social solutions. Innovation can be considered as any change that is beneficial for the entity that introduces it. The challenges that the construction sector faces nowadays are mostly related to the concept of sustainable development. The main trends in innovations are the shift towards more resource- and energy-efficientways of construction as well as implementing the principles of the circular economy. In this article, we present innovative technologies applied in the construction sector that meet the requirements of sustainable development. Also, we propose a method for assessing the environmental impact of innovative technologies currently used in the construction sector. As the proposed methods are primarily based on expert knowledge, it was necessary to determine the risk of making a wrong decision to apply innovative technology in practice based on an assessment made by a person with appropriate competencies.

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Mieczysław Henryk Dzierzgowski

Laboratory measurements and analyses conducted in a wide range of changes of water temperature and mass flow rate for different types of radiators allowed to provides limitations and assessment of the current radiators heat transfer model according to EN 442. The inaccuracy to determinate the radiator heat output according to EN 442, in case of low water mass flow rates may achieve up to 22.3% A revised New Extended Heat Transfer Model in Radiators NEHTMiRmd is general and suitable for different types of radiators both new radiators and radiators existing after a certain period of operation is presented. The NEHTMiRmd with very high accuracy describes the heat transfer processes not only in the nominal conditions—in which the radiators are designed, but what is particularly important also in operating conditions when the radiators water mass flow differ significantly from the nominal value and at the same time the supply temperature changes in the whole range radiators operating during the heating season. In order to prove that the presented new model NEHTMiRmd is general, the article presents numerous calculation examples for various types of radiators currently used. Achieved the high compatibility of the results of the simulation calculations with the measurement results for different types of radiators: iron elements (not ribbed), plate radiators (medium degree ribbed), convectors (high degree ribbed) in a very wide range of changes in the water mass flow rates and the supply temperature indicates that a verified NEHTMiRmd can also be used in designing and simulating calculations of the central heating installations, for the rational conversion of existing installations and district heating systems into low temperature energy efficient systems as well as to directly determine the actual energy efficiency, also to improve the indications of the heat cost allocators. In addition, it may form the basis for the future modification of the European Standards for radiator testing.

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Lech Łobocki, Paola Porretta-Tomaszewska

Gradient-based implicit similarity functions are derived theoretically from a few variants of the Mellor–Yamada algebraic turbulence-closure model under assumptions of local equilibrium conditions in a stably stratified shear flow. The solutions are compared with empirical functions presented by Sorbjan. Good agreement is found in the range of gradient Richardson number Ri extending up to around 0.2. The gradient-based scaling framework offers better accuracy and reliability than the traditional Monin–Obukhov framework, as it circumvents the problems of small values of fluxes and cross-correlations. It is also possible to separate the specification of themaster length-scale fromthe calculation of similarity functions describing second moments and dissipation rate. The related discussion of model performance at higher Ri is included. It is unclear whether the current countermeasures against spurious flow decoupling reflect the observed features of turbulence in the very stable regime, due to the apparent breakdown of the Richardson–Kolmogorov energy cascade, as found by Grachev et al.

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Dorota Pusłowska-Tyszewska

Allocating finite water resources between different water uses is always a challenging task. Searching for a solution which satisfies the water needs (requirements) of all water users without compromising the water requirements of river ecosystems calls for analyzing different water management options and their expected consequences. Water management balances are usually used for comparison of water resources with the needs of water users. When aquatic and water dependent ecosystems are considered in a similar manner as other users, searching for the optimum water resources allocation, without neglecting requirements of the natural environment, is possible. This paper describes basic modeling assumptions and methodological solutions, which allow for taking into account some tasks related to the protection of aquatic and water dependent ecosystems. The water balance model, developed for a catchment comprising the Warta Mouth National Park, was applied to find out whether supplying adequate amounts of water for conservation (or restoration) of wet meadows and wetland habitats in the area is possible, while still satisfying the demands of other water users.

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Mateusz Grygoruk, Ewelina Szałkiewicz, Maria Grodzka-Łukaszewska, Dorota Mirosław-Świątek, Paweł Oglęcki, Dorota Pusłowska-Tyszewska, Grzegorz Igor Sinicyn, Tomasz Okruszko

We studied distributions and abundances of macroinvertebrates in relation to hyporheic water exchange (HWE) patterns of the upper Biebrza a small, lowland, low dynamic European river located in Northeast Poland. On a 6-km stretch of the river; we determined the variability of water exchange in the hyporheic zone by using direct field measurements of the pressure gradient to determine groundwater-surface water interactions. We identified locations with upwelling and downwelling fluxes of HWE as well as ambiguous hydraulic contact between groundwater and surface water along the river. In these locations, we sampled bottom-dwelling macroinvertebrates. In total, 627 individuals of benthic macroinvertebrates of 34 taxa were identified. We revealed that bottom-dwelling macroinvertebrate fauna is more abundant and diverse in river stretches where water from the river infiltrates the hyporheic zone. Results also show higher taxonomic richness and abundances of benthic macroinvertebrates in stretches with diagnosed infiltrating conditions (downwelling flux in a hyporheic zone) compared to in stretches where the river drained groundwater (upwelling flux in a hyporheic zone), but the recorded differences were not statistically significant.

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Michał Kubrak, Agnieszka Malesińska, Apoloniusz Kodura, Kamil Urbanowicz, Paweł Bury, Michał Stosiak

In pressurised pipeline systems, various water hammer events commonly occur. This phenomenon can cause extensive damage or even lead to a failure of the pumping system. The aim of this work is to experimentally re-examine the possibility of using an additional polymeric pipe, installed at the downstream end of the main pipeline, to control water hammer. A previous study on this topic investigated additional polymeric pipes connected to the hydraulic system with a short joint section of the same diameter as the main pipeline. In the current research, a different method of including an additional pipe was considered which involved connecting it with a pipe of a smaller diameter than the main pipeline. Three additional HDPE pipes, with different volumes, were investigated. The performance of the devices was studied for hydraulic transients induced by both rapid and slow, manual valve closures. Experimental results show that the additional polymeric pipe can provide significant pressure surge damping during rapid water hammer events. As the valve closing time lengthens, the influence of the additional pipe on the maximum pressure increase is reduced. The additional HDPE pipe does not provide notable protection against hydraulic transients induced by slow valve closure in terms of reducing the first pressure peak. No relationship between the volume of the additional pipe and the damping properties was noticed. The observed pressure oscillations were used to evaluate a one-dimensional numerical model, in which an additional pipe is described as a lumped parameter of the system. The viscoelastic properties of the device were included using the one element Kelvin–Voigt model. Transient flow equations were solved with the implicit method of characteristics. Calculation results demonstrate that this approach allows one to reasonably reproduce unsteady flow oscillations registered during experiments in terms of the maximum pressure increase and pressure wave oscillation period.

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Krzysztof M. Markowicz, Iwona S. Stachlewska, Olga Zawadzka-Manko, Dongxiang Wang, Wojciech Kumala, Michal T. Chilinski, Przemyslaw Makuch, Piotr Markuszewski, Anna K. Rozwadowska, Tomasz Petelski, Tymon Zielinski, Michal Posyniak, Jacek W. Kamiński, Artur Szkop, Aleksander Pietruczuk, Bogdan H. Chojnicki, Kamila M. Harenda, Patryk Poczta, Joanna Uscka-Kowalkowska, Joanna Strużewska, Malgorzata Werner, Maciej Kryza, Anetta Drzeniecka-Osiadacz, Tymoteusz Sawinski, Arkadiusz Remut, Miroslaw Mietus, Krzysztof Wiejak, Jacek Markowicz, Livio Belegante, Doina Nicolae

The Poland-AOD aerosol research network was established in 2011 to improve aerosol–climate interaction knowledge and provide a real-time and historical, comprehensive, and quantitative database for the aerosol optical properties distribution over Poland. The network consists of research institutions and private owners operating 10 measurement stations and an organization responsible for aerosol model transport simulations. Poland-AOD collaboration provides observations of spectral aerosol optical depth (AOD), Ångstrom Exponent (AE), incoming shortwave (SW) and longwave (LW) radiation fluxes, vertical profiles of aerosol optical properties and surface aerosol scattering and absorption coefficient, as well as microphysical particle properties. Based on the radiative transfer model (RTM), the aerosol radiative forcing (ARF) and the heating rate are simulated. In addition, results from GEM-AQ and WRF-Chem models (e.g., aerosol mass mixing ratio and optical properties for several particle chemical components), and HYSPLIT back-trajectories are used to interpret the results of observation and to describe the 3D aerosol optical properties distribution. Results of Poland-AOD research indicate progressive improvement of air quality and at mospheric turbidity during the last decade. The AOD was reduced by about 0.02/10 yr (at 550 nm), which corresponds to positive trends in ARF. The estimated clear-sky ARF trend is 0.34 W/m2/10 yr and 0.68 W/m2/10 yr, respectively, at TOA and at Earth’s surface. Therefore, reduction in aerosol load observed in Poland can significantly contribute to climate warming.

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Katarzyna Anna Affek, Agnieszka Tabernacka, Monika Załęska-Radziwiłł, Nina Doskocz, Adam Muszyński

Three semi-technical scale biofilters were applied to treat waste gases at different industrial sites in Poland: a mechanical–biological treatment plant of municipal solid waste, a wastewater treatment plant and a food industry plant. Two types of materials were used as beds in the biofilters: stumpwood chips and pine bark, and stumpwood chips, pine bark and compost from green waste. Both bed materials supported the microbial growth and high numbers (106–108 cfu/g dry mass (DM)) of culturable bacteria, and fungi in beds were observed. There was no correlation between the number of microorganisms (cfu/g DM) and the respiratory activity in the biofilter beds. However, microbial respiration activity corresponded with microbial abundance expressed as microbial equivalents (ME), which was calculated based on adenosine triphosphate (ATP) determination. The biofilters either reduced or increased bioaerosol emissions from industrial plants, depending on the microbial content in the waste gases. A high microbial content in the waste gases made the effect of microbial emission from the biofilter bed negligible. The type of biofilter bed and number of microorganisms in the bed also influenced the final bioaerosol emission, but these factors were relevant for biofilters that treated waste gases with low microbial concentrations.

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Djouadi Djahida, Ghomari Tewfik, Maciej Witek, Mechri Abdelghani

Composite overwraps are a cost-effective repair technology, appropriate for corrosion defects, dents, and gouges for both onshore and offshore steel pipelines. The main benefit of polymer-based sleeves is safe installation without taking the pipeline out of service. This paper presents a new calculation procedure proposed in the form of an algorithm for the sizing of composite repairs of corroded pipelines when the sleeve is applied at zero internal pressure. The main objective of the presented methodology is determination of the effective thickness of the composite repair without its overestimation or underestimation. The authors used a non-linear finite element method with constitutive models allowing analysis of the steel, putty, and composite structures. The validation of the results of numerical computations compared to the experimental ones showed an appropriate agreement. The numerical calculations were applied to compare the analytical results in relation to those obtained by the standards ASME PCC-2 or ISO/TS 24817. The comparison showed that the proposed solution confirmed its effectiveness in reducing the thickness of the sleeve significantly, thus, showing that the current industrial standards provide a considerably excessive composite wrap around the steel pipe corroded area, which leads to an unnecessary increase in the repair costs.

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Katarzyna Affek, Adam Muszyński, Nina Doskocz, Monika Załęska-Radziwiłł

Treated wastewater may provide an effective alternative for meeting agriculture’s demands and increase freshwater resources for other needs. Disinfection of treated wastewater protects the receivers; nevertheless, hazards of handling disinfectants, and the fact that some of them do not remove certain pathogenic and opportunistic organisms, are two main reasons for undertaking research in this field. Ecotoxicity of effluent from a full-scale wastewater treatment plant, subjected to disinfection by chlorination, ozonation and UV irradiation, was investigated under laboratory conditions. The efficiency of bacterial inactivation was examined: microorganisms were sensitive to chlorine and UV disinfection, however, they were more resistant to ozonation. Ecotoxicity was evaluated on samples before disinfection and on disinfected samples in which the bacterial inactivation level was similar. Immobilization, growth and enzymatic ecotoxicological tests were performed using consumers, producers and decomposers, respectively. UV irradiation had the least negative impact on the tested bioindicators. Although some studies have shown opposite trends, it has been proved that ozonation and chlorination increase the toxicity of treated wastewater. This study suggests that the wide application of disinfectants to wastewater should be reviewed because, under the experimental conditions tested, they were able to cause harmful effects on one or more of the species tested and they could adv ersely affect biodiversity in the environment.

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Ekrem Tunçbilek, Anna Wiktoria Komerska, Müslüm Arıcı

In contrary to current studies in the literature, mostly concerning continuously operation system, this paper explores the effect of heating/cooling operation schedule on the determination of optimum insulation thickness (OIT) and location by studying different intermittent heating and cooling strategies. With this aim, two different cases, corresponding to house and office, were investigated for the climatic conditions of Ankara, Turkey, and compared with the continuous case. Performed analyses show that the optimum insulation thickness is highly dependent on the operation mode of buildings. When an intermittent heating and cooling strategy is applied, the OIT values remarkably differ from the continuous case (reducing by up to 2 folds), showing potential savings resulting from the energy management system. Locating the insulation material at the external wall surface was found to be more effective irrespective of the operation mode of the building. Furthermore, effects of applying OIT under the intermittent operation on the indoor air temperature fluctuations, energy consumption and level of greenhouse gas emissions are investigated. Most profound energy savings are observed for heating mode. For all the studied cases, the reduction in the total energy and global warming potential is between 52–74%, and 37–62%, respectively.

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Wojciech Dąbrowski, Beata Karolinczak, Paweł Malinowski, Lech Magrel

The problem of wastewater treatment from craft breweries emerged in Poland about 10 years ago when an increase in the number of small breweries was observed. Plants located in small towns are forced to solve the problem on their own. One of the possibilities is to use low-cost technology of constructed wetlands with subsurface and surface flow. The purpose of the research was to test the possibility of effective treatment of sewage from a craft brewery in a lab-scale research installation and to determine the parameters for designing a real scale plant. Wastewater from the Waszczukowe brewery was used in the study. The research system consisted of a retention and aeration tank, SS-VF subsurface flow and FWS surface flow beds. An innovative Certyd filling produced by LSA company was used. The high efficiency of SS-VF bed and the entire research system was found. The removal efficiency in SS VF was on average 89.7% for BOD5, 90.5% for COD, 54.6% for TN and 52.1% for TP. For whole treatment it was respectively 97.1%, 96.7%, 72.6% and 61.3%. A high organic matter removal effect was found for the SS-VF bed (87.1 g BOD5 m-2 d-1) and a relatively low for the FWS (3.0 BOD5 g m-2 d-1). The study confirmed the need for plant design based on hydraulic load and required load removed per unit area.

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Kamil Kiełbasiński, Paweł Dobak, Łukasz Dominik Kaczmarek, Sebastian Kowalczyk

Reliability of equilibrium state evaluation about settlement slopes in the context of natural and human-made hazards is a complex issue. The geological structure of the vicinity of the upland slope in the urban environment of Warsaw is characterised by a significant spatial diversification of the layers. This is especially due to the glacitectonics in the Mio-Pliocene clays, which are located shallowly under the sandy tills’ formations. With substantial variability in the clay roof surface, point recognition by drilling is often insufficient. The use of electrical resistivity imaging (ERI) in the quasi-3D variant provides accurate images of the real ground conditions, which is crucial in optimal geotechnical design. In forecasting the behaviour of the slope, it is necessary to quantify the impact of spatially differentiated systems of disturbed layers on changes in the safety factor (SF), which corresponds to the observed landslide activity of the Warsaw Slope. This study concerns numerous calculation model analyses of the optional clay position in the context of slope stability conditions. A wide range of soil properties variability was taken into account, resulting from both lithogenesis and subsequent processes disintegrating the original soil structure. Regarding the geological conditions of the slip surface, the use of classical computational methods and numerical modelling (FEM) was considered for comparative purposes. The results indicated that local changes in equilibrium conditions were affected by the different morphology of the clay roof surface of the slope and the alternation in strength characteristics on the slip surfaces. The findings of the study contribute to sustainable spatial planning of near-slope regions.

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Karol Paweł Szymankiewicz, Jacek W. Kamiński, Joanna Strużewska

One of the most important minor species in the atmosphere is nitrogen dioxide (NO2). The primary objective of the presented research was to propose a method to adjust emission inventories (emission fluxes) using tropospheric NO2 columns observed by OMI and SCIAMACHY instruments. Modified emission fluxes were used in a chemical weather model GEM-AQ. The GEM-AQ model results were compared with the monthly averaged satellite-derived column amount of NO2 over Europe for the 2008–2010 observing period. It was shown that the observed and modelled spatial distribution of high values of the NO2 column is highly correlated with the distribution of major anthropogenic sources in the modelling domain. The presented findings highlight the importance of the anthropogenic sources in the overall budget of NO2 in the polluted troposphere. Regions for which modelling results showed underestimation or overestimation compared with observations were constant for the whole analysis period. Thus, the NO2 column observations could be used for correcting emission estimates. The proposed emission correction method is based on the differences in modelled and satellite-derived NO2 columns. Modelling was done for 2011 using the original and adjusted emission inventories and compared with observed NO2 columns. The analysis was extended to compare modelling results with surface NO2 observations from selected air quality stations in Poland. A significant improvement in modelling results was obtained over regions with large overestimations in the control run for which the original emission fluxes were used.

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Aleksandra Bogdanowicz, Monika Żubrowska-Sudoł, Andrzej Ryszard Krasiński, Mirosław Sudoł

Research conducted so far on the presence of microplastics in the environment shows that these items are ubiquitous pollutants and therefore constitute an inherent part of our lives. This constitutes a significant problem in many aspects, and one of them is the correct identification of microplastics in environmental samples. Environmental samples can be easily contaminated by plastic microparticles from other sources if proper precautions are not taken during sampling and analysis. The consequence of not taking this cross-contamination into account when analysing the results may be their significant overestimation. This review aims to draw attention to the problem of cross-contamination that accompanies the collection and analysis of samples for the presence of microplastics, and to discuss this issue in a comprehensive manner. The article indicates potential sources of cross-contamination, lists the mitigation methods, and describes the possibilities of assessing this type of contamination. Moreover, the review examines how cross-contamination control appears in practice, based on the available literature data.

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Zbigniew Kledyński, Paweł Falaciński, Agnieszka Machowska, Łukasz Szarek, Łukasz Krysiak

Hardening slurries (water-bentonite-binder mixtures) constitute a well-established material used broadly, i.a., for cut-off walls in civil and water engineering. Although they usually contain Portland cement, similar to common concrete, their properties differ greatly, mostly due to a much higher water content. This characteristic of hardening slurries creates unique opportunities for the utilization of significant quantities of industrial by-products that are deemed problematic in the concrete industry. This article investigates the effect of the addition of by-products of fluidized-bed combustion of hard, brown coal and municipal sewage sludge, as well as ground granulated blast furnace slag, on the properties of slurries. Unconfined compressive strength tests, as well as mercury porosimetry, scanning electron microscopy, and X-ray diffraction analyses were performed. The results suggest that it is possible to design hardening slurry mixes of desired properties, both in liquid and solid state, containing at least 100–300 kg/m3 of industrial waste. This includes cement-free slurries based entirely on industrial by-products as binders. In addition, the analyzed slurries exhibited good chemical resistance to landfill eluates, at the same time effectively immobilizing heavy metals. It was concluded that hardening slurry technology can ensure the safe deposition of significant amounts of waste that would be otherwise difficult to manage, thus contributing to the circular economy concept.

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Falaciński Paweł, Machowska Agnieszka, Szarek Łukasz

The article discusses the results of examining the impact of aggressive solutions on specimens of mortars with a slag-ash binder. Bar specimens were exposed to unidirectional diffusion of sodium chloride and sodium sulphate for 90 days. Next, the specimens were subjected to flexural and compressive strength tests, ion content tests, XRD phase composition tests, and microstructural SEM-EDS tests. The test results indicated that aggressive solution action resulted in decreased flexural strength, however, it did not impact the compressive strength of mortars. A minor impact of chloride ions on the pThe article discusses the results of examining the impact of aggressive solutions on specimens of mortars with a slag-ash binder. Bar specimens were exposed to unidirectional diffusion of sodium chloride and sodium sulphate for 90 days. Next, the specimens were subjected to flexural and compressive strength tests, ion content tests, XRD phase composition tests, and microstructural SEM-EDS tests. The test results indicated that aggressive solution action resulted in decreased flexural strength, however, it did not impact the compressive strength of mortars. A minor impact of chloride ions on the pH of the pore liquid was recorded, while the tests did not show any influence of sulphate ions. Furthermore, aggressive ion concentration decreased in deeper specimen slices. Specimen phase composition testing after chloride ion action indicated the presence of a small amount of Friedel’s salt, while regular sodium chloride crystals were identified in the microscopic image. The performance properties of mortars exposed to the action of aggressive solutions were maintained. H of the pore liquid was recorded, while the tests did not show any influence of sulphate ions. Furthermore, aggressive ion concentration decreased in deeper specimen slices. Specimen phase composition testing after chloride ion action indicated the presence of a small amount of Friedel’s salt, while regular sodium chloride crystals were identified in the microscopic image. The performance properties of mortars exposed to the action of aggressive solutions were maintained.

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Dorota Mirosław-Świątek , Paweł Popielski, Piotr Śliwiński, Tomasz Cwalina, Zdzisław Skutnik

River embankments are the basic and the oldest measures of protecting areas potentially subjected to flooding, and at the same time pose a serious threat to their environment in the event of damage or failure. The technical condition of the levees and its regular evaluation is a key element of their safety. A general assessment of the technical condition of a levee is the result of many interacting factors and parameters that depend on each other to a varying degree. Therefore, it is necessary to consider the cause-and-effect links between the interrelationships of numerous parameters and sensors of significant impact. In this article the decision-making trial and evaluation laboratory (DEMATEL) method was applied to develop a cause-and-effect model for factors impacting the condition and safety of levees. Effective factors impacting the technical condition of a levee were identified; relationships between these factors were determined; a cause-and-effect model was developed based on identified factors; factors were categorized based on the dependence scale and influential indicators of each factors used in the DEMATEL method. The obtained results demonstrate that three following factors: hydrological factor, type and condition of soils in levee body and condition of levee areas (inter-levee and landside) play the most important role for levee safety. The results of this study can support traditional assessments of hydrotechnical structure or assist entities managing levees.

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Bartosz Bednarz, Paweł Popielski, Rafał Sieńko, Tomasz Howiacki, Łukasz Bednarski

Due to the low costs of distributed optical fibre sensors (DFOS) and the possibility of their direct integration within layered composite members, DFOS technology has considerable potential in structural health monitoring of linear underground infrastructures. Often, it is challenging to truly simulate the actual ground conditions at all construction stages. Thus, reliable measurements are required to adjust the model and verify theoretical calculations. The article presents a new approach to monitor displacements and strains in Glass Fiber Reinforced Polymer (GFRP) collectors and pipelines using DFOS. The research verifies the effectiveness of the proposed monitoring solution for health monitoring of composite pipelines. Optical fibres were installed over the circumference of a composite tubular pipe, both on the internal and external surfaces, while loaded externally. Analysis of strain profiles allowed for calculating the actual displacements (shape) of the pipe within its cross-section plane using the Trapezoidal method. The accuracy of proposed approach was positively verified both with reference spot displacement transducer as well as numerical simulations using finite element method (FEM). DFOS could obtain a comprehensive view of structural deformations, including both strains and displacements under externally applied load. The knowledge gained during research will be ultimately used for renovating existing collectors.

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Jacek Hendiger, Marta Chludzińska, Piotr Ziętek

The purpose of this study was to identify the optimal construction of an averaging pitot tube and measure flows typical in building ventilation, considering low-velocity flows. The construction should be simple to implement in variable air volume (VAV) controllers. This paper presents mostly novel constructions, which have not been tested before, and fills the existing gap in low-velocity measurements, which is important considering the correct control with airflow reduction in the VAV system. Eleven constructions based on a circular section of the basic element were chosen. Empirical studies were conducted to determine the aerodynamic properties. The tests were conducted within a typical velocity range in ventilated systems (0.6–7.5 m/s), based on measuring the pressure difference at suitable locations on the upstream and downstream surfaces. The magnification factor (m) was obtained and compared. Sensors consisting of two parallel and slightly separated tubes from each other with upstream and sideward ports on the inner side of the sensor were characterised by a constant and highest value of the factor m (approximately 2.0). These sensors yielded approximately 25% higher values of m than the lowest values. The best sensor constructions among the tested structures were the variants with two parallel tubes with front and side ports from the inner side of the sensor. The application of narrowing and placing of the side port enabled a stable operation in the highest range of velocity.

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August Wrotek, Artur Jerzy Badyda, Piotr O. Czechowski, Tomasz Owczarek, Piotr Dąbrowiecki, Teresa Jackowska

Respiratory syncytial virus (RSV) contributes significantly to pediatric hospitalizations. An association between air pollution and an increased number of RSV cases has been suggested. We sought to evaluate the short-term impact of air pollutants on RSV hospitalizations in Polish children in the period 2010–2019. Daily concentrations of PM10 and PM2.5 (particulate matter with an aerodynamic diameter less than or equal to 10 μm and 2.5 μm, respectively) and nitrogen dioxide (NO2) were analyzed in general regression models (GRM) to establish their influence and full interaction scheme. Significant seasonal and annual periodicity among 53,221 hospitalizations was observed; finally, data from the 2012–2019 RSV high-risk seasons created models for seven agglomerations. The addition of PM2.5, PM10, and NO2 to the basic model for RSV seasonality explained 23% (4.9–31%, univariate model) to 31.4% (8.4–31%, multivariate model) of the variance in RSV hospitalizations. A 10 μg/m3 increase in PM2.5, PM10, and NO2 concentrations was associated with 0.134 (0.087–0.16), 0.097 (0.031–0.087), and 0.212 (0.04–0.29) average increases in hospitalizations, respectively. In the multivariate models, PM2.5, PM10, and NO2 alone, as well as PM2.5–NO2, PM2.5–PM10, and PM10–NO2 interactions, were associated with hospitalizations in some of the locations, while the metaregression showed statistically significant interactions between each of the pollutants, and between the pollutants and the year of the study. The inclusion of PM2.5, PM10, and NO2 in GRM explains a significant number of RSV hospitalizations. The pollutants act alone and interact together in a varied manner. Reducing air contamination might decrease the costs of hospital healthcare.

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Agnieszka Dąbska, Agata Léthel

The objective of this study was to investigate the swelling potential of compacted lime-softening sludge for application in landfill liners. The study involved the assessment of the effect of compaction and moulding moisture content (30–40%), corresponding to the Proctor standard compaction test. One-dimensional oedometer swell tests were conducted using distilled water, tap water, and municipal landfill leachate, resulting in the determination of the expansion indices. Moreover, changes in the moisture content and dry density during the swelling process were investigated. The expansion index was significantly influenced by the initial moisture content and liquid chemistry. Subsequently, these factors also affected the sludge dry density decrease, and its moisture content increase, whereas the impact of the initial dry density on expansion was of low importance. An increase in the sludge moulding moisture content, limited swelling in all liquids used. The highest expansion, dry density, and moisture content changes due to swelling were identified for leachate at w < wopt. It should be underlined that the effect of liquid on the swelling potential faded away along with a further increase in the moisture content w > wopt. The novelty of the work lies in identifying a significant plunge of the expansion index at w ≈ wopt for the leachate swelling test. The lime-softening sludge non-swelling moisture content was defined as wnon ≈ (wopt + 4.0%) − (wopt + 4.5%). For practical engineering implications, the moisture content between (wopt + 2.0%) and (wopt + 4.0%) was provided for the most suitable sludge application in landfill liners.

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Andrzej N. Affek, Edyta Regulska, Ewa Kołaczkowska, Anna Kowalska, Katarzyna Anna Affek

Riparian forests with oaks, ashes and elms, now highly fragmented and rare in Europe, are considered hotspots for ecosystem services. However, their capacity to provide pollination seems to be quite low, although reports from in-situ research supporting this view are scarce. Our goal was therefore to thoroughly assess their pollination potential based on multifaceted field measurements. For this, we selected six test sites with well-developed riparian hardwood forests, located in the agricultural landscape along the middle Vistula River in Poland. We used seven indicators relating to habitat suitability (nesting sites and floral resources) and pollinator abundance (bumblebees and other Apoidea) and propose a threshold value (AdjMax) based on value distribution and Hampel’s test to indicate the level of pollination potential for this type of riparian forest. The obtained AdjMax for bumblebee density was 500 ind. ha−1, for Apoidea abundance—0.42 ind. day−1, while for nectar resources—200 kg ha−1. We demonstrate that the investigated small patches of the riparian hardwood forest have a higher pollination potential than reported earlier for riparian and other broadleaved temperate forests, but the indicators were inconsistent. As forest islands in the agricultural landscape, riparian hardwood forests play an important role in maintaining the diversity and abundance of wild pollinators, especially in early spring when there is still no food base available elsewhere.

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Michał Kubrak, Agnieszka Malesińska, Apoloniusz Kodura, Kamil Urbanowicz, Michał Stosiak

It is well known that the water hammer phenomenon can lead to pipeline system failures. For this reason, there is an increased need for simulation of hydraulic transients. High-density polyethylene (HDPE) pipes are commonly used in various pressurised pipeline systems. Most studies have only focused on water hammer events in a single pipe. However, typical fluid distribution networks are composed of serially connected pipes with various inner diameters. The present paper aims to investigate the influence of sudden cross-section changes in an HDPE pipeline system on pressure oscillations during the water hammer phenomenon. Numerical and experimental studies have been conducted. In order to include the viscoelastic behaviour of the HDPE pipe wall, the generalised Kelvin–Voigt model was introduced into the continuity equation. Transient equations were numerically solved using the explicit MacCormack method. A numerical model that involves assigning two values of flow velocity to the connection node was used. The aim of the conducted experiments was to record pressure changes downstream of the pipeline system during valve-induced water hammer. In order to validate the numerical model, the simulation results were compared with experimental data. A satisfactory compliance between the results of the numerical calculations and laboratory data was obtained.

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Małgorzata Loga, Karol Michał Przeździecki

This article addresses the issue of estimating Pom—the probability of misclassifying the chemical status confidence of a water body status assessment. The main concerns of the authors were chemical quality elements with concentrations in water bodies which are close to or even smaller than the limit of quantification (LOQ). Their values must be set to half of this limit to calculate the mean value. This procedure leads to very low standard deviation values and unrealistic values of Pom for chemical indicators. In turn, this may lead to the false conclusion that not only is the chemical status good but also that this status assessment is perfect. Therefore, for a more reliable calculation of Pom, the authors suggested a modified calculation in which the value of half the LOQ for calculating the mean value was kept, but zero as the concentration value for the standard deviation calculation was adopted. The proposed modification has been applied to the Hierarchical Approach procedure for Pom estimation of the chemical status of Polish rivers and lakes. The crucial finding is that current chemical status assessments may be incorrect in the case of approximately 25% of river water bodies and 30% of lake water bodies categorised as good, and 20% of both types of water bodies classified as below good.

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Mariusz Rogulski, Artur Jerzy Badyda

The coronavirus disease (COVID-19) has caused huge changes in people’s daily habits and had a significant impact on the economy. The lockdowns significantly reduced road traffic and meant that many people worked remotely. Therefore, the question arose as to how the reduced road traffic and stays of residents at home affected the degree of pollution and the structure of major air pollutants. To answer this question, the article presents an analysis of changes in typical air pollutants (PM10, PM2.5, NO2) in the five largest Polish cities and one of the voivodships. The data from the Polish State Environmental Monitoring were used for the analysis. The analysis showed that the period of the first lockdown in Poland (April 2020), despite the reduced road traffic, resulted in a significant increase in PM10 emissions (9–91% during working days and an average of 30% on Saturdays and Sundays), a slight increase in PM2.5 emissions (on average from 2% to 11% for all analyzed locations), and a reduction in NO2 emissions (on average from 6% to 11% for all analyzed locations) compared to the period before the lockdown. However, the changes were not homogeneous—in Łódź and Warsaw, in most cases, an increase in all analyzed pollutants was observed, and the greatest decrease in pollution took place in Małopolska voivodship (including Kraków). Comparing the data from April 2020 to the data from April 2019, the overall difference in the PMs concentrations was small, although there are places where there has been a significant decrease (Wrocław, Poznań), and there were also places where the concentration increased (Warsaw, Łódź, Małopolska). In the case of nitrogen dioxide, pollution concentration decreased in most locations. The only exception was the background stations in Warsaw, where the increase was 27%.

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Bernard Zawada, Joanna Rucińska

The impact of thermal comfort demand on the renovation process was carried out on an optimization basis for the thermo-modernization process of an exemplary single-family home located in Warsaw. The verified TRNSYS simulation program was used to generate a set of variants of building modernization solutions. This variants set was used afterwards as a database for optimization. The analysis performed includes the internal air temperature, indicators of thermal comfort (PPD), and annual energy demand for heating and cooling, and investment costs of modernization building. The results indicated the importance of analyzing various variants of building modernization solutions. Performing modernization without analyzing its effects can have positive as well as negative consequences, e.g., achieving a significant reduction in the primary energy demands at the expense of the deteriorated thermal comfort of users. It was shown that separate analysis of indicators leads to completely different solutions and should not be recommended during modernization of single-family buildings.

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Mechri Abdelghani, Ghomari Tewfik, Maciej Witek, Djouadi Djahida

In this paper, an accurate distribution of stress as well as corresponding factors of stress concentration determination around a spherical cavity, which is considered as embedded in a cylinder exposed to the internal pressure only, is presented. This approach was applied at three main meridians of the porosity by combining the Eshelby’s equivalent inclusion method with Mura and Chang’s methodology employing the jump condition across the interface of the cavity and matrix, respectively. The distribution of stresses around the spherical flaw and their concentration factors were formulated in the form of newly formulated analytical relations involving the geometric ratio of the cylinder, such as external radius and thickness, the angle around the cavity, depth of the porosity, as well as the material Poisson ratio. Subsequently, a comparison of the analytical results and the numerical simulation results is applied to validate obtained results. The results show that the stress concentration factors (SCFs) are not constant for an incorporated flaw and vary with both the porosity depth and the Poisson ratio, regardless of whether the cylinder geometric ratio is thin or thick.

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Michał Jakubczak, Ewa Karwowska, Alicja Fiedorczuk, Agnieszka Jastrzębska

Achieving both effective and sustainable water decontamination technology requires development of a universal filtration solution. However, effective removal of natural waterborne microorganisms still remains a challenge. The use of nanoparticles in water filters is promising but also leads to problems with their efficiency and safety. To cross these bottlenecks, we have designed a novel multifunctional carbon-supported bioactive hybrid nanocomposite filtration bed. For this purpose, we took advantage of granular activated carbon (C), graphene oxide (GO) and bioactive Al2O3/Ag nanocomposite particles (NCP). These components were assembled into a hybrid nanocomposite structure using facile in situ surface decoration via a sol–gel approach. This obtained C/GO/NCP filtration bed was thoroughly characterized in terms of morphology, structure and surface properties as well as further evaluated for tap water filtration efficiency. Analysis of the preferential sites for bacteria adsorption and biological tests under close-to-real static and dynamic filtration conditions has proved C/GO/NCP’s efficiency in eliminating model and natural strains of waterborne microorganisms. At the same time, nanoparticles were not released into the filtrate, which confirmed material stability and safety. We have also revealed that C/GO/NCP nanofiltration bed was self-sterilizing which means that it entirely eliminated up to 100% of the filtered bacteria cells within short periods of contact time. What is more, the low-temperature thermal regeneration allowed recovering the assumed properties. In general, the obtained results indicate a breakthrough in designing hybrid-structured filtration beds that can be easily synthesized and safely used for drinking water decontamination.

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P. Dąbrowiecki, Ł. Adamkiewicz, Dominika Mucha, P.O. Czechowski, Mateusz Soliński, A. Chciałowski, Artur Jerzy Badyda

Ambient air pollution impairs lung development in children, particularly in industrialized areas. The air quality in Zabrze, a city located in the Upper Silesian Industrial Region of Poland, is among the worst in Europe. We compared lung function and the frequency of respiratory or allergic symptoms between children living in Zabrze and those living in Gdynia, a city on the Baltic coast, which has the best long-term air quality in Poland. We enrolled children aged 9–15 years from both cities who were able to perform a spirometry. The following spirometry variables were measured for all participants: forced vital capacity (FVC), forced expiratory volume during the first second of expiration (FEV1), FEV1/FVC index, and peak expiratory flow (PEF). The frequencies of respiratory or allergic symptoms were taken from a survey completed by the participants’ parents. In total, 258 children from Gdynia and 512 children from Zabrze were examined. The mean values of FVC, FEV1, and PEF were significantly greater among children in Gdynia than those reported in Zabrze (p ≤ 0.032), and the frequencies of seasonal rhinorrhea (p = 0.015) or coughing episodes (p = 0.022) were significantly higher in Zabrze than in Gdynia. In conclusion, lung function was significantly impaired in children living in Zabrze, an area which is associated with poor air quality. Strategies to improve air quality in the Silesia region are urgently needed.

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Agnieszka Malesińska, Michał Kubrak, Mariusz Rogulski, P. Puntorieri, V. Fiamma, G. Barbaro

Contractions and expansions are common features in various types of pipeline systems. The purpose of this study is to investigate the influence of a sudden cross section change on transient pressure waves. The paper presents laboratory data and numerical calculations of pressure oscillations during the valve-induced water hammer in serially connected steel pipes. Five different variants of experiments were conducted which included recording pressure changes at the downstream end of the pipeline system. The more sections with different diameters there are connected in series, the more complex the transient wave recorded is. Laboratory data indicate a significant influence of individual pipeline sections on the final course of pressure oscillations. Transient equations were solved using the explicit MacCormack scheme. In order to numerically simulate water hammers in pipe series, the improved junction boundary condition was established. It involves assigning two sets of values, which describe flow parameters, to the connection node thus causing it to act as two separate nodes. The numerical model was calibrated with the unsteady friction factor. The derivation of equations that take into account a sudden change in diameter in the connected pipes allowed the reproduction of the wave nature of the water hammer phenomenon, results were satisfactory as compared to experimental data. The numerical model correctly reproduced pressure wave interactions and pressure amplitudes.

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Adam Muszyński, Agnieszka Tabernacka, Monika Załęska-Radziwiłł

The aim of the study was to assess the bioaerosol removal efficiency by a semi-technical scale combined biofilter used to treat waste gas from a food industry plant. Two types of biofilter beds were tested: stumpwood chips and pine bark (CB) and stumpwood chips, pine bark and compost (CBC). Two types of membranes (covering the surface of the bed) were examined as the second stage of treatment: Pro Eko Tex UV (M1) and Pro Eko Tex UV 6 (M2). A conventional open biofilter (without membranes) was an emitter of microorganisms. There was no statistically significant difference between the number of bacteria emitted from CB or CBC beds, but fungal concentration was three times higher in gas treated by the CBC bed. The use of the membranes as the second stage of gas treatment significantly reduced the bacterial emission (74–78%) from the biofilter regardless of the bed and the membrane tested. The M1 membrane was also efficient in fungi removal from the treated gas by 80–97%. However, the M2 membrane could have been slowly colonized by fungi and have become an additional emitter of fungi in the system.

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Ratajczak, Artur Jerzy Badyda, P.O. Czechowski, A. Czarnecki, M. Dubrawski, W. Feleszko

A substantial proportion of airway disease’s global burden is attributable to exposure to air pollution. This study aimed to investigate the association between air pollution, assessed as concentrations of particulate matter PM2.5 and PM10 on the upper respiratory tract symptoms (URTS) in children. A nation-wide, questionnaire-based study was conducted in Poland in winter 2018/2019 in a population of 1475 children, comparing URTS throughout the study period with publicly available data on airborne particulate matter. A general regression model was used to evaluate the lag effects between daily changes in PM10 and PM2.5 and the number of children reporting URTS and their severity. PM10 and PM2.5 in the single-pollutant models had significant effects on the number of children reporting URTS. The prevalence of URTS: “runny nose”, “sneezing” and “cough” was positively associated with 12-week mean PM2.5 and PM10 concentrations. In the locations with the highest average concentration of PM, the symptoms of runny nose, cough and sneezing were increased by 10%, 9% and 11%, respectively, compared to the cities with the lowest PM concentrations. This study showed that moderate-term exposure (12 week observation period) to air pollution was associated with an increased risk of URTS among children aged 3–12 years in Poland. These findings may influence public debate and future policy at the national and international levels to improve air quality in cities and improve children’s health.

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Mert Tükel, Ekrem Tunçbilek, Anna Wiktoria Komerska, Gülşen Aydın Keskin, Müslüm Arıcı

Classification of climatic zones is required for building thermal regulation. In this context, a novel approach based on thermoeconomic analysis is proposed to reclassify climatic zones of Turkey. The classification is carried out by accounting different climatic-built parameters, namely thermal insulation, main wall component, fuel type, as well as heating and cooling degree-days (HDD and CDD). With this aim, 80 provinces of Turkey are reclassified into 5 zones based on fuzzy c-means clustering method regarding 27 different optimum insulation thickness attributes calculated for each city. The results showed that compared to the current national thermal zones, based only on HDD values, 16 out of 80 provinces shift to a new category, all of which correspond to a higher zone indicating the requirement of a thicker insulation layer. The results are presented with membership degrees giving more insight into the climate of analysed cities, discussed in terms of reduction in energy-cost and global greenhouse gas emissions. The obtained new classification revealed that the current national thermal zoning methodology is inadequate in division of the studied geographical area particularly for mild climates where cooling needs are significant. Finally, an updated climate zone map of Turkey for building thermal regulation is proposed.

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Sasan Sadrizadeh, Amar Aganovic, Anna Bogdan, Cong Wang, Alireza Afshari, Anne Hartmann, Cristiana Croitoru, A. Khan, Martin Kriegel, Merethe Lind, Zhijian Liu, Arsen Melikov, Jinhan Mo, Hansjörg Rotheudt, Runming Yao, Yixian Zhang, Omid Abouali, Håkon Langvatn, Olof Sköldenberg, Guangyu Cao

Ventilation systems are the primary way of eliminating airborne pathogenic particles in an operating room (OR). However, such systems can be complex due to factors such as different surgical instruments, diverse room sizes, various staff counts, types of clothing used, different surgical types and duration, medications, and patient conditions. OR ventilation should provide a thermally comfortable environment for the surgical staff team members while preventing the patient from suffering from any extreme hypothermia. Many technical, logistical, and ethical implications need to be considered in the early stage of designing a ventilation system for an OR. Years of research and a significant number of publications have highlighted the controversy and disagreement among infection specialists, design engineers, and ventilation experts in this context. This review article aims to provide a good understanding of OR ventilation systems in the context of air quality and infection control from existing research and provide multidimensional insights for appropriate design and operation of the OR. To this end, we have conducted a systematic review of the literature, covering 253 articles in this context. Systematic review and meta-analyses were used to map the evidence and identify research gaps in the existing clinical, practical, and engineering knowledge. The present study is categorized into six research focuses: ventilation system, thermal comfort, staff work practice and obstacles, door operation and passage, air cleaning technology, emission rate, and clothing systems. In the conclusion, we summarize the key limitations of the existing studies and insights for future research direction.

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Jérôme Barré, Hervé Petetin, Augustin Colette, Marc Guevara, Vincent-Henri Peuch, Laurence Rouil, Richard Engelen, Antje Inness, Johannes Flemming, Carlos Pérez García-Pando, Dene Bowdalo, Frederik Meleux, Camilla Geels, Jesper H. Christensen, Michael Gauss, Anna Benedictow, Svetlana Tsyro, Elmar Friese, Joanna Strużewska, Jacek W. Kaminski, John Douros, Renske Timmermans, Lennart Robertson, Mario Adani, Oriol Jorba, Mathieu Joly, Rostislav Kouznetsov

This study provides a comprehensive assessment of NO2 changes across the main European urban areas induced by COVID-19 lockdowns using satellite retrievals from the Tropospheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5p satellite, surface site measurements, and simulations from the Copernicus Atmosphere Monitoring Service (CAMS) regional ensemble of air quality models. Some recent TROPOMI-based estimates of changes in atmospheric NO2 concentrations have neglected the influence of weather variability between the reference and lockdown periods. Here we provide weather-normalized estimates based on a machine learning method (gradient boosting) along with an assessment of the biases that can be expected from methods that omit the influence of weather. We also compare the weather-normalized satellite-estimated NO2 column changes with weather-normalized surface NO2 concentration changes and the CAMS regional ensemble, composed of 11 models, using recently published estimates of emission reductions induced by the lockdown. All estimates show similar NO2 reductions. Locations where the lockdown measures were stricter show stronger reductions, and, conversely, locations where softer measures were implemented show milder reductions in NO2 pollution levels. Average reduction estimates based on either satellite observations (−23 %), surface stations (−43 %), or models (−32 %) are presented, showing the importance of vertical sampling but also the horizontal representativeness. Surface station estimates are significantly changed when sampled to the TROPOMI overpasses (−37 %), pointing out the importance of the variability in time of such estimates. Observation-based machine learning estimates show a stronger temporal variability than model-based estimates.

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Andrzej J. Osiadacz, Małgorzata Kwestarz

The major optimization problem of the gas transmission system is to determine how to operate the compressors in a network to deliver a given flow within the pressure bounds while using minimum compressor power (minimum fuel consumption or maximum network efficiency). Minimization of fuel usage is a major objective to control gas transmission costs. This is one of the problems that has received most of the attention from both practitioners and researchers because of its economic impact. The article describes the algorithm of steady-state optimization of a high-pressure gas network of any structure that minimizes the operating cost of compressors. The developed algorithm uses the “sequential quadratic programming (SQP)” method. The tests carried out on the real network segment confirmed the correctness of the developed algorithm and, at the same time, proved its computational efficiency. Computational results obtained with the SQP method demonstrate the viability of this approach.

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Edyta B. Hendiger, Marcin Padzik, Inés Sifaoui, María Reyes-Batlle, Atteneri López-Arencibia, Diana Zyskowska, Marta Grodzik, Anna Pietruczuk-Padzik, Jacek Hendiger, Gabriela Olędzka, Lidia Chomicz, José E. Piñero, Jacob Lorenzo-Morales

Acanthamoeba keratitis (AK), a severe sight-threatening corneal infection, has become a significant medical problem, especially among contact lens wearers. The disease manifests as eye pain, congestion, blurred vision, lachrymation, and ring-shaped infiltrates of the cornea, and can lead to permanent blindness. Inappropriate habits of contact lens users may result in an increased risk of AK infection. The anti-amoebic efficiency of popular multipurpose contact lens solutions is insufficient to reduce this risk. An effective and non-toxic therapy against AK has not yet been developed. The prevention of AK is crucial to reduce the number of AK infections. Nanoparticles are known to be active agents against bacteria, viruses, and fungi and were also recently tested against protozoa, including Acanthamoeba spp. In our previous studies, we proved the anti-amoebic and anti-adhesive activity of silver nanoparticles against Acanthamoeba castellanii. The aim of this study is to evaluate the activity, cytotoxicity, and anti-adhesive properties of silver nanoparticles conjugated with five commonly used multipurpose contact lens solutions against the Acanthamoeba castellanii NEFF strain. The obtained results show a significant increase in anti-amoebic activity, without increasing the overall cytotoxicity, of Solo Care Aqua and Opti Free conjugated with nanoparticles. The adhesion of Acanthamoeba trophozoites to the contact lens surface is also significantly reduced. We conclude that low concentrations of silver nanoparticles can be used as an ingredient in contact lens solutions to decrease the risk of Acanthamoeba keratitis infection.

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Agnieszka Pusz, Magdalena Paulina Wiśniewska, Dominik Rogalski

The contamination of soils with metals applies, in particular, to areas related to industry, the mining of raw materials and ores, transport, and agriculture. Unlike organic materials, metals cannot degrade over time and need to be reduced, removed, or immobilized in soil. One of the remediation methods for soils contaminated with metals is phytoextraction, which uses plants’ ability to accumulate metals in their own tissues. Metals enter the plant organism through the roots and are transported to the aboveground parts, where they are accumulated. In this study, we evaluated the phytoaccumulative abilities of two plant species tested on soils from industrial areas contaminated with metals to different extents (Zn, Cd, Ni, Pb, Cr, and Cu). The research was conducted for three years under the conditions of a pot experiment. In order to obtain four soils with varying degrees of metal contamination, two soils from industrial areas, G1 (contaminated) and G2 (uncontaminated), were mixed in the following ratios: 1:1, 1:3, 1:7, and 1:9. In the phytoremediation process, Festuca rubra L. and Alyssum saxatile L. were tested. After analyzing the results of the bioconcentration factor (BCF) for the tested plants, it was noted that both of the tested plants accumulated Cd and Zn more easily, followed by Cu, Ni, and Cr, and then Pb to a lesser extent. The values of factors for Cd and Zn were correlated with the high mobility of these elements compared to other metals and their relatively easy uptake by plants. Alyssum saxatile L. has an ability to accumulate Cd compared to Festuca rubra L., which is confirmed by the BCF (0.764) and transfer factor (TF) (3.5) (for 1:7 combination) values. The calculated results for the BCFs for Alyssum saxatile L. are less than one for all tested metals, which allows us to state that Alyssum saxatile L. is not an accumulator.

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Piotr Fabijańczyk, Jarosław Zawadzki

The purpose of this study was to use fast geophysical measurements of soil magnetic susceptibility (κ) as supplementary data for chemical measurements of selected light rare earth elements (REEs) in soil. In order to ensure diversity in soil conditions, anthropogenic conditions and types of land use, seven areas were selected, all located in regions subjected to past or present industrial pollution. Magnetometric parameters were measured using a selected magnetic sensor that was specially designed for measurements of soil cores and were used to classify collected soil cores into six distinctive types. The analysis of REEs concentrations in soil was carried out taking into account the grouping of collected soil samples based on the type of study area (open, forested and mountain), and additionally on the measured magnetometric parameters of collected soil cores. A use of magnetometric measurements provided different, but complementary to chemical measurements information, which allowed to obtain deeper insight on REEs concentrations in soils in studied areas.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafin

Municipal waste treatment plants are an important element of the urban area infrastructure, but also, they are a potential source of odour nuisance. Odour impact from municipal waste processing plants raises social concerns regarding the well-being of employees operating the plants and residents of nearby areas. Chemical methods involve the determination of the quantitative composition of compounds comprising odour. These methods are less costly than olfactometry, and their efficiency is not dependent on human response. The relationship between the concentration of a single odorant and its odour threshold (OT) is determined by the odour activity value (OAV) parameter. The research involved the application of a multi-gas detector, MultiRae Pro. Measurements by means of the device were conducted at three municipal waste biogas plants located in Poland. In this paper we describe the results obtained when using a detector during the technological processes, the unitary procedures conducted at the plants, and the technological regime. The determination of these relationships could be useful in the development of odour nuisance minimization procedures at treatment plants and the adjustment to them. This is of paramount importance from the viewpoint of the safety and hygiene of the employees operating the installations and the comfort of residents in the areas surrounding biogas plants. Monitoring of expressed odorant emissions allows the course of technological processes and conducted unit operations to be controlled.

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Zbigniew Kledyński, Paweł Falaciński, Agnieszka Machowska, Łukasz Szarek, Łukasz Krysiak

Hardening slurries (water-bentonite-binder mixtures) constitute a well-established material used broadly, i.a., for cut-off walls in civil and water engineering. Although they usually contain Portland cement, similar to common concrete, their properties differ greatly, mostly due to a much higher water content. This characteristic of hardening slurries creates unique opportunities for the utilization of significant quantities of industrial by-products that are deemed problematic in the concrete industry. This article investigates the effect of the addition of by-products of fluidized-bed combustion of hard, brown coal and municipal sewage sludge, as well as ground granulated blast furnace slag, on the properties of slurries. Unconfined compressive strength tests, as well as mercury porosimetry, scanning electron microscopy, and X-ray diffraction analyses were performed. The results suggest that it is possible to design hardening slurry mixes of desired properties, both in liquid and solid state, containing at least 100–300 kg/m3 of industrial waste. This includes cement-free slurries based entirely on industrial by-products as binders. In addition, the analyzed slurries exhibited good chemical resistance to landfill eluates, at the same time effectively immobilizing heavy metals. It was concluded that hardening slurry technology can ensure the safe deposition of significant amounts of waste that would be otherwise difficult to manage, thus contributing to the circular economy concept.

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Olgierd Niemyjski, Ryszard Zwierzchowski

This paper explores how water temperature changes in a district heating system (DHS) impact the monitoring of water losses. Water volume in DHS is constantly monitored, recorded, and replenished. The leakage and failure status of the DHS is often monitored through measuring the make-up water flow rate. In this paper, we present the methodology and a simplified model of the dynamics of the heating system operation, which was used to determine the profile of changes in the average temperature and density of water in the system. The mathematical model of the district heating network (DHN) was verified by comparing the results of simulation calculations, i.e., calculated values of the temperature of water returning to the heat source, with the measured values. Fluctuations in water temperature cause changes in the density and volume of water in the DHN, which affect the amount of water supplementing the system. This is particularly noticeable in a DHN with a large water volume. The study reports an analysis of measurement results of operating parameters of a major DHS in Poland (city of Szczecin). Hourly measurements were made of supply and return water temperature, water flow rate, and pressure throughout the whole of 2019. The water volume of the analyzed DHN is almost 42,000 m3 and the changes in water volume per hour are as high as 5 m3/h, representing 20–30% of the value of the make-up water flow rate. The analysis showed that systems for monitoring the tightness of the DHS and detecting failures, on the basis of measurements of the make-up water flow rate, should take into account the dynamics of water volume changes in the DHN.

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Radosław Żyłka, Beata Karolinczak, Wojciech Dąbrowski

The aim of the research was to determine the indicators of electricity consumption in every stage of the dairy sewage treatment process in relation to the sewage flow and the load of removed organics (BOD5, COD) and nutrients (TN, TP). The research was conducted in a dairy wastewater treatment plant (WWTP) consisting of mechanical treatment, averaging tank, dissolved air flotation (DAF) and biological treatment with sequence batch reactors (SBRs). Energy consumption was measured with the help of transducers. Indicators of unit electricity consumption were determined on the basis of 95 measurement series of energy consumption, sewage flow and removed load. The mean value of total unit energy consumption relating to the flow for the entire WWTP was 2.29 kWh·m−3, while for biological treatment 1.17 kWh·m−3 and 0.05 kWh·m−3 for DAF. The mean values of indicators relating to removed pollutants load for the entire WWTP were: 1.89 kWh·kgrem BOD5−1, 1.30 kWh·kgrem COD−1, 48.61 kWh·kgrem TN−1 and 160.01 kWh·kgrem TP−1. During biological treatment, energy consumption indicators were on average: 1.65 kWh·kgrem BOD5−1 and 1.19 kWh·kgrem COD−1, 52.90 kWh·kgrem TN−1 and 141.26 kWh·kgrem TP−1, while for DAF: 0.12 kWh·kgrem BOD5−1, 0.09 kWh·kgrem COD -1, 3.85 kWh·kgrem TN−1 and 16.17 kWh·kgrem TP−1. It was found that the biological treatment in SBRs was responsible for 54.1% of the total energy consumption of dairy WWTP. Aerobic sewage sludge treatment accounted for 17.0% of total consumption, mechanical treatment 17.1%, deodorization 2.6%, and other (social, lighting etc.) 6.9%, while DAF only 2.3%. The real-time electricity metering system enabled the optimisation of the electricity consumption in the WWTP, taking into account its consumption in unit processes and the removed pollutants load. The application of this system enabled to make corrections that reduced energy consumption while maintaining the required treatment efficiency.

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Mirosław Szyłak-Szydłowski

As a result of compounds’ transformation in the waste biostabilization phases, there is an increase in odor nuisance and health problems among people exposed to odorants. Linking the odor concentration to the degree of waste biostabilization may be an important tool for the assessment of individual technological variants of biostabilization. The study aimed to link the odor emissions to the biostabilization degree in individual process variants that differed in the inoculum. The tests were carried out on inoculated windrows on the waste mechanical-bological treatment open site. Odor concentrations were measured during the entire seven-week process of biostabilization (weeks 1–7) and compared with kinetics parameters of organic compounds’ decomposition. The olfactometric tests showed the necessity of using the preparation to reduce the value of odor concentration. Research proved that the decrease of odor concentration values could be useful to indicate the particular phases of biostabilization. Also, the proposed method provides an opportunity to optimize the process concerning the function related to the low degree of odor nuisance of the technologies, including selection of environmentally safe inoculum. This issue has application values that may result in the implementation of new control systems for waste stabilization bioreactors and the evaluation of applied technological solutions.

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Agnieszka Pusz , Magdalena Paulina Wiśniewska , Dominik Rogalski

Various factors can lead to the transformation of metal forms and to an increase in their solubility and, consequently, their mobility. One solution to the problem of increased solubility is the use of carbons as additives to soil in order to limit the potential migration of contaminants. The aim of this study was to determine the effect of using brown coal and activated carbon on metal forms that are available to plants. The mineral composition of the coals used in a pot experiment was analyzed. Observations were carried out with a JJSM-6380 LA scanning electron microscope (SEM) connected to an EDS electron micro-probe. The total contents of Zn, Cd, Pb and Cu in the assessed soils as well as the content of available metal forms were determined after single extractions with different reagents, namely 1 M NH4NO3, DTPA and 1 M HCl. Generalized linear models (GLMs) were used to evaluate the effectiveness of the stabilization methods in a long-term pot experiment. The carbons reduced the percentage of these forms relative to the total metal content in the soil. After adding brown coal, Zn, Cd, Pb and Cu forms were reduced by up to 32%, 30%, 33% and 43%, respectively. After adding activated carbon, the metal forms of Zn, Cd, Pb and Cu were reduced by up to 47%, 44%, 40% and 50%, respectively. The following order of extracted metal forms with different solutions was found: HCl: Zn > Pb > Cu > Cd; DTPA: Pb > Zn > Cu > Cd; NH4NO3: Zn > Cu > Pb > Cd. Eight years after setting up the pot experiment, the contents of humic substances in soils with the addition of both tested carbons were compared, and the soils with added carbons were found to have a stable content of humic fractions. The costs of remediation through the stabilization method using the tested brown coal and activated carbons do not exceed USD 75/t (taking into account the double doses of both carbons).

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Maciej Witek, Ferdinand Uilhoorn

This paper investigates the influence of failure of transmission network key elements on security of natural gas delivery. The proposed framework combines the probabilistic structure integrity study and the hydraulic analysis. A factor called a volumetric loss was introduced to quantify the effect of network failure. Based on the magnetic flux leakage diagnostics, the rupture probability of steel tube plastic collapse was estimated using a random variable method and Monte Carlo solution. In-line inspections should monitor only the rate of tube wall corrosion, whereas the proposed methodology enables the pipeline operator to evaluate the system ability to deliver gas at the customer nodes. For the hydraulic analysis, an unsteady gas flow model was applied using conservation principles of mass, momentum, and energy. The flow model was tuned to real pressure and temperature data using a multi-objective optimization approach. To demonstrate the practical value of the methodology, the time and amount of gas shortage, line pack, and a volumetric loss were computed for a real tree-topological pipeline network. Simulations demonstrated that the highest volumetric loss is experienced when both compressor stations are shut down. The aim of the proposed algorithm is identification of critical nodes as well as evaluation of measures for improving the gas supply reliability to the customers.

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Maria Grodzka-Łukaszewska , Zofia Agnieszka Pawlak , Grzegorz Igor Sinicyn

The aspects of surface stability and groundwater exchange recognized by many researchers due to the intensification of agriculture and industry (manifested in, e.g., regulation and dredging of riverbed sediments of rivers) are now widely discussed on the international forum of water policy and management. It is essential to assess the spatial variability of water exchange through the river length and cross sections for the preparation of data and calculation of the groundwater flow model. This article presents research which describes the spatial distribution of the surface water-groundwater interaction within the river cross-section. Two measurement series were carried out to describe its variability. Additionally, a groundwater flow model was developed to simulate and represent the variable nature of water exchange in the hyporheic zone in the river’s cross-section. The model was successfully verified by means of measurements of water flux in the hyporheic zone. The precise spatial description of this variability is the first step to determine the possibility of introducing this variable in an accurate manner, within the limits of measurement uncertainties or simulation assumptions, in the construction of mathematical models of groundwater flow.

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Leszek Ornoch , Paweł Popielski , Andrzej Olszewski , Adam Kasprzak

Building inclinations can be measured through the use of ultrasonic hydrostatic levelers. These are used to measure long-term relative displacements of vertical parts of structures and utilize the principle of communicating vessels (similar to the classic water scales). The presented ultrasonic displacement measurement technique was developed by Ultrasystem in the 1990s and was applied to several objects in Poland. Long-term measurements enabled the development of a model of object behavior under the influence of various factors. Among these are the annual cycle of temperature changes, fluctuating water levels, turbine chamber emptying, etc. Such a model can facilitate the prediction of failure based on the appearance of changes deviating from typical behavior (e.g., a much stronger dependence of the inclination as a function of the water level). The results obtained with the help of ultrasonic sensors enable the observation of subtle deformations of the object, which is valuable when developing and calibrating new models of the object (e.g., by means of the finite element method).

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Anatoly Hurynovich, Marian Kwietniewski, Valentin Romanovski

The starting point for the research discussed in this study was the assumption that sewage sludge generated by wastewater treatment plants (WWTP) should be treated as a valuable raw material in the Circular Economy. Hence, the results of the research are part of the search for the best technological solutions aimed at achieving the maximum possible efficiency of sludge management in WWTP. The research was carried out on the example of a sewage treatment plant in Minsk (the capital of Belarus), where the dominant technology is still the storage of sewage sludge, and annually more than 5 million tons of sludge accumulates, which represents a significant hazard to the environment. The research takes into account the real economic, environmental, economic and social conditions in this country. As an alternative to the current technology, which is no longer recommended in EU countries, the effectiveness of three technological solutions was analyzed: (1) thermophilic digestion option with the production of biogas and subsequent combustion of the fermented sludge in the territory of treatment facilities, (2) high-temperature drying followed by the use of sludge in cement production and (3) production of fertilizers (soil-improving additives). A comparative analysis of these technologies was performed by the ranking method using weighting indicators (significance factors). The methodology takes into account technical, economic, environmental and social criteria. As a result of the evaluation, it was found that the most effective technology for the management of sewage sludge of the WWTP in Minsk is the technology of drying and then using the sludge as an alternative fuel in cement production. This technology provides, among others waste-free utilization of the entire volume of sewage sludge generated in Minsk, and also gives opportunities to create new jobs in the area of production of alternative fuel from sewage sludge.

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Maciej Witek

The main goal of this paper is to evaluate the burst pressure and structural integrity of a steel pipeline based on in-line inspection results, in respect to the grouping criteria of closely spaced volumetric surface features. In the study, special attention is paid to evaluation of data provided from the diagnostics using an axial excitation magnetic flux leakage technology in respect to multiple defects grouping. Standardized clustering rules were applied to the corrosion pits taken from an in-line inspection of the gas transmission pipeline. Basic rules of interaction of pipe wall metal losses are expressed in terms of longitudinal and circumferential spacing of the features in the colony. The effect of interactions of the detected anomalies on the tube residual strength evaluated according to the Det Norske Veritas Recommended practice was investigated in the current study. In the presented case, groups of closely-spaced defects behaved similarly as individual flaws with regard to their influence on burst pressure and pipeline failure probability.

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Magdalena Młynarczyk, Anna Bogdan, Tomasz Jankowski

Thermal conditions in operating rooms are mainly dictated by the need to meet the safety/comfort requirements of the patient. However, the accuracy of performed surgical procedures depends on the surgeon and others members of medical team. Hence, their comfort sensation should be also factored in. The study sought to find out how thermal sensations of people working in surgical clothing can be modified through a local change in air velocity and temperature around the user. A series of tests was carried out with a thermal manikin to make an accurate assessment of the effectiveness of this type of equipment. The tests included changes of the ambient temperature, supply air temperature and air velocity. The operational efficiency was assessed on the basis of the equivalent temperature index (teq). Results show that the final result of teq was mostly determined by air velocity rather than the supply air temperature.

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Marta Wiśniewska, Mirosław Szyłak-Szydłowski

The mechanical-biological waste treatment plants (MBTP), which include the municipal waste biogas plants, have an important role in sustainable urban development. Some plants are equipped with a sewage pre-treatment plant, which is then directed to the sewerage system and the treatment plant. Others, on the other hand, have only a non-drainage tank. The parameters of technological sewage (TS) or processing technology could reduce sewage contamination rates. In addition to the quality of sewage from waste treatment plants, the emission of odours is also an important problem, as evidenced by the results obtained over the sewage pumping station tank. The conducted statistical analysis shows a significant positive correlation between odour concentration (cod) and volatile organic compounds (VOCs). Analysing the individual compounds, a high positive correlation was also found—the strongest being between H2S, NH3 and VOCs. In the case of sewage compounds, the insignificant correlation between P total and other parameters was found. For the rest of the compounds, the highest positive correlation was found between COD and BOD and N-NO2 and N-NH3 as well as COD and N-NO2. The dilution of sewage is only an ad hoc solution to the problem. Further work should be aimed at reducing sewage pollution rates. The obtained results indicate large pollution of technological sewage and a high level of odour and odorants concentration. The novelty and scientific contribution presented in the paper are related to analyses of various factors on technological sewage parameters and odour and odorant emission from TS tank at biogas plant processing municipal waste, which may be an important source of knowledge on the management of TS, its disposal and minimisation of emitted compound emissions.

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Łukasz Adamkiewicz , Katarzyna Maciejewska , Krzysztof Skotak , Michal Krzyzanowski , Artur Jerzy Badyda , Katarzyna Juda-Rezler , P. Dąbrowiecki

In this study Health Impact Assessment (HIA) methods were used to evaluate potential health benefits related to keeping air pollution levels in Poland under certain threshold concentrations. Impacts of daily mean particulate matter (PM)10 levels on hospital admissions due to cardiovascular and respiratory diseases were considered. Relative risk coefficients were adopted from WHO HRAPIE project. The analyses covered period from 2015 to 2017, and were limited to the heating season (1st and 4th quarter of the year), when the highest PM10 concentrations occur. The national total number of hospital admissions attributed to PM10 concentration exceeding WHO daily Air Quality Guideline value of 50 µg/m3 was calculated for each of the 46 air quality zones established in Poland. We found that the reduction of the attributable hospital admissions by 75% or 50% of that expected for the “best case scenario”, with no days with PM10 concentration exceeding 50 µg/m3 would require avoidance of exceedance by the daily mean PM10 concentration of 64 µg/m3 and 83 µg/m3, respectively. These concentrations were proposed as the information and alert thresholds, respectively. The alert thresholds were exceeded on 2 and 38 days per year in the least and the most polluted zones, respectively. Exceedances of the information thresholds occurred on 6 and 66 days in these zones.

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Paweł Gilewski

Precipitation is a key variable in the hydrological cycle and essential input data in rainfall-runoff modeling. Rain gauge data are considered as one of the best data sources of precipitation but before further use, the data must be spatially interpolated. The process of interpolation is particularly challenging over mountainous areas due to complex orography and a usually sparse network of rain gauges. This paper investigates two deterministic interpolation methods (inverse distance weighting (IDW), and first-degree polynomial) and their impact on the outputs of semi-distributed rainfall-runoff modeling in a mountainous catchment. The performed analysis considers the aspect of interpolation grid size, which is often neglected in other than fully-distributed modeling. The impact of the inverse distance power (IDP) value in the IDW interpolation was also analyzed. It has been found that the best simulation results were obtained using a grid size smaller or equal to 750 m and the first-degree polynomial as an interpolation method. The results indicate that the IDP value in the IDW method has more impact on the simulation results than the grid size. Evaluation of the results was done using the Kling-Gupta efficiency (KGE), which is considered to be an alternative to the Nash-Sutcliffe efficiency (NSE). It was found that KGE generally tends to provide higher and less varied values than NSE which makes it less useful for the evaluation of the results.

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Katarzyna Juda-Rezler , Elwira Zajusz-Zubek , Magdalena Marta Reizer , Katarzyna Maciejewska , Eliza Kurek , Ewa Bulska, Krzysztof Klejnowski

The analysis of bioavailability and potential risk to human health of trace and minor elements bound to atmospheric PM2.5 was carried out at an urban background site in Warsaw, Poland during a 40-day winter period. The samples were sequentially extracted into four different fractions: water soluble (F1), reducible (F2), oxidizable (F3) and residual (F4) for the chemical fractionation of 8 elements: As, Cd, K, Mn, Pb, Sb, Ti and Zn, and further analyzed using inductively coupled plasma mass spectrometry in each fraction. The average PM2.5 mass concentration of 31.81 μg/m3 (±19.73 μg/m3) was exceeding daily WHO air quality guideline, while concentrations rose up to 50–70 μg/m3 during episode days. Total concentrations of all analyzed elements were higher during the episode periods, with the highest increases for K, Pb (2 times) and Cd (1.7 times). All elements exhibited high bioavailability, as well as very high (K, Ti, Zn) and high (As, Cd, Mn, Pb, Sb) risk assessment code, with both features rising in episodic days up to 20% and more than 60%, respectively. Cancer risk for adults resulted from inhalation exposure to the most bioavailable fractions (F1 and F2) of human carcinogen As. It was higher than the precautionary criterion (1 · 10−6) and increased during the days with elevated PM2.5 levels.

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Jan Bogacki , Piotr Marcinowski , Dominika Bury , Monika Krupa , Dominika Ścieżyńska , Prasanth Prabhu

There is a need for more effective methods of industrial wastewater treatment. Methods: Cosmetic wastewater was collected and subjected to H2O2/Fe3O4/Fe2O3/Fe0 and UV/H2O2/Fe3O4/Fe2O3/Fe0 process treatment. Results: Total organic carbon (TOC) was decreased from an initial 306.3 to 134.1 mg/L, 56.2% TOC removal, after 120 min of treatment for 1:1 H2O2/COD mass ratio and 500/500/1000 mg/L Fe3O4/Fe2O3/Fe0 catalyst doses. The application chromatographic analysis allowed for the detection and identification of pollutants present in the wastewater. Identified pollutants were removed during the treatment processes. Processes carried out at a pH greater than 3.0 were ineffective. The UV process was more effective than the lightless process. Conclusions: The applied processes are effective methods for wastewater treatment. Chromatographic results confirmed the effectiveness of the treatment method. The kinetics of the process were described by the modified second-order model. On the basis of ANOVA results, the hypothesis regarding the accuracy and reproducibility of the research was confirmed.

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Michał Jakubczak , Ewa Karwowska , Anita Rozmysłowska-Wojciechowska , Mateusz Petrus , Jarosław Woźniak , Joanna Mitrzak , Agnieszka Jastrzębska

Point-of-use (POU) water treatment systems and devices play an essential role in limited access to sanitary safe water resources. The filtering materials applied in POU systems must effectively eliminate contaminants, be readily produced and stable, and avoid secondary contamination of the treated water. We report an innovative, 2D Ti3C2/Al2O3/Ag/Cu nanocomposite-modified filtration material with the application potential for POU water treatment. The material is characterized by improved filtration velocity relative to an unmodified reference material, effective elimination of microorganisms, and self-disinfecting potential, which afforded the collection of 99.6% of bacteria in the filter. The effect was obtained with nanocomposite levels as low as 1%. Surface oxidation of the modified material increased its antimicrobial efficiency. No secondary release of the nanocomposites into the filtrate was observed and confirmed the stability of the material and its suitability for practical application in water treatment.

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Łukasz Szarek, Łukasz Krysiak

Owing to the increasing popularity of the thermal treatment of municipal sewage sludge (TTMSS) in Poland, constant growth in the quantity of ash generated within this process has been recorded. Due to their properties, it is difficult to utilize this type of ash within the concrete production technology. One of the methods of waste utilization is to add it to hardening slurries, used in, among others, cutoff walls. The slurry operating conditions (contact with groundwater) and elevated heavy metal content in ash raise justified concerns in terms of environmental safety of the aforementioned methods. In the study, the release of heavy metals from a matrix, namely, the hardened slurry has been examined. The so-called “batch test” dynamic leachability testing method was applied for this purpose. A high level of heavy metal immobilization in the slurry was achieved. The obtained results indicate an environmentally safe possibility of using TTMSS ash in hardening slurries in cut-off walls.

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Łukasz Adamkiewicz , Maciej Kryza , Dominika Mucha , Małgorzata Werner , Anna Gayer , Anetta Drzeniecka-Osiadacz , Tymoteusz Sawiński

Emissions from the household sector are the most significant source of air pollution in Poland, one of the most polluted countries in the EU. Estimated health impacts of the reduction of these emissions under three scenarios are presented. The EMEP4PL model and base year emission inventory were used to estimate average annual PM10 and PM2.5 concentrations with spatial resolution of 4 km × 4 km. The change in emissions under each of the scenarios was based on data from a survey on household boilers and insulation. Scenario 1 included replacement of all poor-quality coal-fired boilers with gas boilers; Scenario 2 included replacement of all poor-quality coal-fired boilers with low-emission boilers but still using solid fuels; and Scenario 3 included the thermal refurbishment of houses with the worst insulation. Impacts on the following health parameters were estimated: premature deaths (PD), Chronic Bronchitis (CB), Bronchitis in Children (BiC) and Work Days Lost (WDL). The concentration–response functions recommended by the WHO HRAPIE project were used. The analysis was conducted for two regions: Lower Silesia and Lodzkie province. The largest reduction of health impact was observed for Scenario 1. For Lower Silesia, the annual PD decreased by 1122 (34.3%), CB by 1516 (26.6%), BiC by 9602 (27.7%) and WDL by 481k (34.7%). For Lodzkie province, the largest impacts were estimated as decreases in PD by 1438 (29.9%), CB by 1502 (25.3%), BiC by 9880 (26.8%) and WDL by 669k (30.4%).

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Edyta B. Hendiger , Marcin Padzik , Agnieszka Żochowska , Wanda Baltaza , Gabriela Olędzka , Diana Zyskowska , Julita Bluszcz , Sylwia Jarzynka , Lidia Chomicz , Marta Grodzik , Jacek Hendiger , José E. Piñero , Jarosław Grobelny , Katarzyna Ranoszek-Soliwoda , Jacob Lorenzo-Morales

Background Free-living amoebae of the genusAcanthamoebaare cosmopolitan, widely distributed protozoans that cause a severe, vision-threatening corneal infection known asAcanthamoebakeratitis (AK). The majority of the increasing number of AK cases are associated with contact lens use. Appropriate eye hygiene and effective contact lens disinfection are crucial in the prevention of AK because of the lack of effective therapies against it. Currently available multipurpose contact lens disinfection systems are not fully effective againstAcanthamoebatrophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent AK infections. Synthesized nanoparticles (NPs) have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that some plant metabolites, including tannins, have anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of tannic acid-modified silver NPs (AgTANPs) conjugated with selected multipurpose contact lens solutions.MethodsThe anti-amoebic activities of pure contact lens care solutions, and NPs conjugated with contact lens care solutions, were examined in vitro by a colorimetric assay based on the oxido-reduction of alamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analysed by ANOVA and Student-Newman-Keuls test usingP< 0.05 as the level of statistical significance.ResultsWe show that the NPs enhance the anti-Acanthamoebaactivities of the tested contact lens solutions without increasing their cytotoxicity profiles. The activities are enhanced within the minimal disinfection time recommended by the manufacturers.ConclusionsThe conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach for the prevention of AK infections among contact lens users.

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Humidity-sensitive, demand-controlled ventilation systems have been in use for many years in regions with oceanic climates. Some attempts have been made to apply this technology in Poland, which has a continental climate. This article evaluates the performance and energy consumption of such a system when applied in an eight-floor, multiunit, residential building, i.e., the virtual reference building described by the National Energy Conservation Agency (NAPE), Poland. Simulations using the computer program CONTAM were performed for the whole heating season based upon the climate in Warsaw. Besides passive stack ventilation, that served as a reference, two ventilation systems were studied: one standard and one “hybrid” system with additional roof fans. This study confirmed that the application of humidity-sensitive, demand-controlled ventilation in multiunit residential buildings in a continental climate (Dfb) led to significant energy savings (up to 11.64 kWh/m2 of primary energy). However, the operation of the system on higher floors was found to be ineffective. Ensuring consistent operation of the system on all floors required supplementary fans. The introduction of a hybrid mode reduced carbon dioxide concentrations by approximately 32% in the units located in the upper part of the building. The energetic effect in such cases depends strongly on the electricity source. In the case of the national energy grid, savings of primary energy would be relatively low, i.e., 1.07 kWh/m2, but in the case of locally produced renewable energy, the energy savings would be equal to 5.18 kWh/m2.

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Marta Wiśniewska , Andrzej Kulig , Krystyna Lelicińska-Serafin

Municipal waste biogas plants are an important element of waste treatment and energy policy. In this study, odorant concentrations and emissions were measured together with the air temperature (T) and relative humidity (RH) to confirm the hypothesis that the microclimatic conditions have an important impact on the level of odorant emission at municipal waste biogas plants. A simple correlation analysis was made to evaluate the strength and the direction of the relationship between the odorant concentration and emission and air temperature and relative humidity. The mean volatile organic compound (VOC) and NH3 concentrations vary depending on the stage of the technological line of the analysed municipal waste biogas plants and are in the following ranges, respectively: 0–38.64 ppm and 0–100 ppm. The odorant concentrations and emissions correlated statistically significantly with T primarily influences VOC concentrations and emissions while RH mainly affects NH3 concentrations and emissions. The strongest correlations were noted for the fermentation preparation section and for emissions from roof ventilators depending on the analysed plant. The smallest influence of microclimatic factors was observed at the beginning of the technological line—in the waste storage section and mechanical treatment hall. This is due to the greater impact of the type and quality of waste delivered the plants. The analysis of correlation between individual odorants showed significant relationships between VOCs and NH3 for most stages of the technological line of both biogas plants. In the case of technological sewage pumping stations, a significant relationship was also observed between VOCs and H2S. The obtained results may be helpful in preparing strategies to reduce the odours from waste treatment plants.

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Beata Karolinczak , Rafał Miłaszewski , Wojciech Dąbrowski

Analysis of the current knowledge has revealed the lack of a method for increasing the cost-effectiveness of wastewater and septage treatment in plants overloaded by contamination. This was the premise for undertaking research on the process of septage pre-treatment in a subsurface vertical flow constructed wetland (SS-VF) prior to its input into the biological section of a municipal treatment plant. In previous research the authors have indicated that this allows for a significant reduction in the value of pollution indicators. The objective of this paper is to assess the cost-effectiveness of this process by means of an optimization model. The decision variable was the coefficient of septage stream distribution into the quantity directed to the SS-VF bed in relation to its total quantity. The optimization criterion was the minimization of the expected annual cost of wastewater and septage treatment. Verification of the model has shown that it is reasonable to subject all septage to the pre-treatment in a SS-VF bed for small wastewater treatment plant (WWTPs) located in rural areas. The bigger the septage pollution load is, the greater the reduction in the treatment costs. The proposed solution is less cost-effective in urban areas, where the construction of a SS-VF bed requires land purchase and additional costs of its adjustment. Optimization results largely depend on the cost function, so it is important to build it on reliable local data.

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Artur Jerzy Badyda , Piotr Krawczyk , Jan S. Bihałowicz , Karolina Bralewska , W. Rogula-Kozłowska , G Majewski , Przemysław Oberbek , Andrzej Marciniak , Mariusz Rogulski

The study attempts to compare the total annual emissions of selected air pollutants emitted during occasional grilling and the emission of the same pollutants from small domestic heating installations. For this purpose, in the absence of any data on the emission of pollutants during grilling processes, tests were carried out consisting of measuring the concentration of air pollutants in exhaust streams from two types of grills (solid fuel grill powered by charcoal briquette and gas grill powered by liquid propane), using popularly prepared dishes (previously marinated meat and raw, seasoned mixed vegetables). The concentrations of PM2.5, CH4, CO, CO2, H2O, NH3, N2O, NO, NO2, SO2 were measured in the exhaust stream from both grills using a particulate matter (PM) measuring device and a portable spectrometer, separately while grilling the same portions of meat and vegetables. Then, considering the available data on Poles’ barbecue habits, the emissions that are released into the air during occasional grilling were estimated. The calculated emissions were compared with the data on emissions from domestic heating installations used in Poland. It has been shown that during grilling, as much as 2.30, 92.07, 4.11, 3.83, 2.96, and 9.81 Gg of PM2.5, CO, NOx, SO2, NH3, and CH4 may be released into the atmosphere in Poland, respectively. In the case of PM, the amount of the pollutant emitted to the air is over 100 times lower than the emissions caused by the operation of small heating installations. In the case of other pollutants, the differences are smaller. Nevertheless, emissions from grills should not be underestimated as, in certain periods of the year, these sources may be responsible for not meeting the air quality standards in selected areas of the country, and thus the excessive exposure of people to pollutants resulting in negative health consequences. Therefore, attention was paid to the legitimacy of abandoning the use of charcoal and charcoal briquette grills and replacing them with gas-powered grills or electric ones, not only due to the health benefits of food and lower human exposure, but also by the reason of ecological values.

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Jerzy Kwiatkowski , Joanna Rucińska

The need to achieve energy consumption and greenhouse gas emission decreases within the building sector requires the implementation of a supportive legal framework. To fulfil this requirement, a building certification system must be developed that is easily understandable for end users. In Poland, assessments of the energy performance of buildings are based on primary energy indicator verification. However, this parameter is difficult to understand for building owners or for tenants. Therefore, in this study, energy efficiency class limits and a heating indicator for energy needs indicator have been estimated for multi-family buildings in Poland. To achieve this purpose, a reference building was used and 180 calculation variants were developed, which considered the following variables: 3 types of climate data, 4 values of building shape ratios, 3 types of ventilation, 3 thermal transmittance standards and 3 windows area ratios to the external wall. The results showed that the greatest influences on the need for energy used for heating were the type of ventilation used and the local climate. This study shows that the methodology used is adequate for energy efficiency class limits estimations involving multi-family buildings in Poland.

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M. Diaz, Grzegorz Igor Sinicyn, Maria Grodzka-Łukaszewska

The objective of the present paper is to develop a methodology that could allow the representation of the analytical hyporheic flux equation model (AHF) in a numerical model done in MODFLOW. Therefore, the scope of the research is to show the viability of the methodology suggested in a real case (Biebrza river, Poland, Europe). Considering that the model requires extensive manipulation in the creation of the packages, a test phase through the seepage package of MODFLOW is carried out with the aim of representing the river package of MODFLOW. FloPy is the tool chosen to develop this implementation due to the versatility of manipulating the packages available in MODFLOW through coding. The obtained results showed a correct implementation of the AHF model using the example of the Biebrza River. The results obtained will enable a better understanding regarding the modelling of the interaction between the river and the aquifer, considering streams with specific geometries where the depth is dimensionally higher than the width.

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Michał Kubrak

This paper investigates the influence of a fiber optic cable inserted into a straight steel pipeline on pressure oscillations occurring during the rapid water hammer phenomenon. In order to numerically simulate water hammer in the pipeline with an inserted cable, a one-dimensional model with variable pressure wave speeds was used. The required smoothing of the pressure wave was obtained by introducing a diffusion coefficient into the momentum equation. Transient equations were solved using a modified finite-element method. The numerical model was calibrated with the dissipation coefficient based on the results of our own experimental tests. In the experimental study, four different types of cables and three values of initial flow rates have been considered. The obtained values of the calibrated dissipation coefficient are directly proportional to the initial water flow velocity. The results demonstrate that this approach allows one to reproduce the damping of pressure oscillations accurately and to obtain satisfactory results compared to experimental data for a given range of volumetric flow rates.

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Anna Rolewicz-Kalińska , Krystyna Lelicińska-Serafin , Piotr Manczarski

The analysis of biofiltration efficiency was performed with parallel VOC, H2S and NH3 removal using pilot two-stage biofilters including conventional biofiltration and purification on a membrane filter. The scope of the research was to determine the relationship between the technological parameters of the tested device (two beds and two membranes) and gases removal efficiency. Research was carried out in a semi-technical scale in three industrial plants: mechanical-biological municipal waste treatment (MBT), food industry (FI) and wastewater treatment (WWTP) plants. Experimental results indicate the efficiency removal of VOCs from 89% (WWTP) to 98% (FI), NH3 from 88% (WWTP) to 100% (MBT) and H2S from 93% (WWTP) to 100% (MBT). Biofilter with stumpwood chips-bark-compost bed, fortified with the more porous membrane was the most effective, allowing VOC, NH3 and H2S removal with an average efficiency of 99% for NH3 and H2S and 97% for VOCs. The application of membrane fabrics as the second stage of purification allows high efficiency simultaneous removal of VOCs, NH3 and H2S. Unlike two-stage purification, conventional biofiltration is effective at removing individual impurities from process gases. The results of this study indicate a high potential for practical application.

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Piotr Marcinowski, Dominika Bury, Monika Krupa, Dominika Ścieżyńska, Prasanth Prabhu, Jan Bogacki

Wastewater from a cosmetic factory, with an initial total organic carbon (TOC) of 146.4 mg/L, was treated with Fe2O3/Fe0/H2O2, Fe3O4/Fe0/H2O2, light/Fe2O3/Fe0/H2O2, and light/Fe3O4/Fe0/H2O2 processes. The light-supported processes were more effective than the lightless processes. The fastest TOC removal was observed during the first 15 min of the process. Out of the four tested kinetic models, the best fit was obtained for the modified second-order reaction with respect to the TOC value. The best treatment efficiency was obtained for the light/Fe3O4/Fe0/H2O2 process with 250/750 mg/L Fe3O4/Fe0 reagent doses, a 1:1 hydrogen peroxide to Chemical Oxygen Demand (H2O2/COD) mass ratio, and a 120 min process time. These conditions allowed 75.7% TOC removal to a final TOC of 35.52 mg/L and 90.5% total nitrogen removal to a final content of 4.9 mg/L. The five-day Biochemical Oxygen Demand to Chemical Oxygen Demand (BOD5/COD) ratio was increased slightly from 0.124 to 0.161. Application of Head Space Solid-Phase Microextraction Gas Chromatography Mass Spectrometry (HS-SPME-GC-MS) analysis allows for the detection and identification of 23 compounds contained in the raw wastewater. The identified compounds were eliminated during the applied process. The HS-SPME-GC-MS results confirmed the high efficiency of the treatment processes.

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Anita Rozmysłowska-Wojciechowska , Ewa Karwowska , Michał Gloc , Jarosław Woźniak , Mateusz Petrus , Bartłomiej Przybyszewski , Tomasz Wojciechowski , Agnieszka Jastrzębska

A recent discovery of the unique biological properties of two-dimensional transition metal carbides (MXenes) resulted in intensive research on their application in various biotechnological areas, including polymeric nanocomposite systems. However, the true potential of MXene as an additive to bioactive natural porous composite structures has yet to be fully explored. Here, we report that the addition of 2D Ti3C2Tx MXene by reducing the porosity of the chitosan-hyaluronate matrix nanocomposite structures, stabilized by vitamin C, maintains their desired antibacterial properties. This was confirmed by micro computed tomography (micro-CT) visualization which enables insight into the porous structure of nanocomposites. It was also found that given large porosity of the nanocomposite a small amount of MXene (1–5 wt.%) was effective against gram-negative Escherichia coli, gram-positive Staphylococcus aureus, and Bacillus sp. bacteria in a hydrogel system. Such an approach unequivocally advances the future design approaches of modern wound healing dressing materials with the addition of MXenes.

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Michał Sobieraj

An experimental evaluation of an autocascade refrigeration (ACR) system was carried out. A zeotropic mixture of isobutane and CO2 was employed as a working fluid in an autocascade refrigeration (ACR) system. An experimental system was designed and built to study the influence of the recuperative heat exchanger (RHX) and openings of the throttle valves on the system performance. The use of RHX facilitated the condensation process and improved the cycle characteristics. The working mass concentration of CO2 was higher, as it was closer to the nominal concentration and the discharge pressure was lower by 19% to even 39% when the RHX was employed in the system. An increase of up to 20% in the coefficient of performance (COP) was observed. Furthermore, the effects of the openings of the throttle valves on the system characteristics were studied. The change in the openings of the expansion valves affected the mass flows and the working mixture composition. The working CO2 mass fraction increased with higher openings of the evaporator throttle. The subcooling degree of liquid CO2-rich refrigerant increased with higher openings of the expansion valve under the phase separator. The results of the present work should be helpful for design and optimization of autocascade systems working with natural and synthetic refrigerants.

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Edwin Koźniewski, Karolina Banaszak

In this paper, we present a new approach for the analysis of the dependence of construction costs on the geometric shape of a building. Instead of difficult or even impossible-to-establish uniform prices and costs, we propose a cost analysis concerning the amount of materials needed for construction. We show that the basic parameters are the base area of the building (plan), assumed in the study as the building area, and the area of the external walls of the building. The amount of consumption of most materials is proportional to the base area and the area of the external walls. The materials required for construction consume large amounts of energy during their manufacture. Therefore, shape optimization is not only economically significant for the investor but is also important in terms of the energy consumption, i.e., embodied energy. We propose a set of indicators to help a designer optimize the shape of the building at the initial design stage.

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Andrzej J. Osiadacz , Niccolo Isoli

The main goal of this paper is to prove that bi-objective optimization of high-pressure gas networks ensures grater system efficiency than scalar optimization. The proposed algorithm searches for a trade-off between minimization of the running costs of compressors and maximization of gas networks capacity (security of gas supply to customers). The bi-criteria algorithm was developed using a gradient projection method to solve the nonlinear constrained optimization problem, and a hierarchical vector optimization method. To prove the correctness of the algorithm, three existing networks have been solved. A comparison between the scalar optimization and bi-criteria optimization results confirmed the advantages of the bi-criteria optimization approach.

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Marta Wiśniewska , Andrzej Kulig , Krystyna Lelicińska-Serafin

Biogas plants processing municipal waste are very important investments from the point of view of waste management and also the sustainable development of urban infrastructures. They may also have a potentially negative impact on the environment in the form of odour emission. Olfactometry is the main method for odour impact assessment. Field olfactometry allows for performing a wide range of tests, the results of which are practically instantaneous. The purpose of this work is to provide a tool for assessing the odour impacts of municipal management facilities, including biogas plants processing municipal waste and evaluating the correctness of processes carried out in these plants, namely the method of field olfactometry. In order to compare obtained olfactometric results with the concentration of chemical compounds, chromatographic tests were also carried out using the Photovac Voyager portable chromatograph (hydrogen sulphide – H2S and dimethyl sulphide – (CH3)2S. The results of the odour concentration tests are in line with the results of odorant concentration tests and indicate that cod is strongly related to the concentration of hydrogen sulphide. Thanks to this method, it is possible to find a relationship between odour nuisance, technological processes used in the plant and the type of treated waste.

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Łukasz Szarek

An increasing number of municipal sewage treatment plants in Poland, desirable from an environmentalperspective, raises the problem of managing the growing volume of sewage sludge. The thermal treatment ofmunicipal sewage sludge (TTMSS) method, by greatly reducing the waste volume, increases the heavy metalconcentration in fly ash (primary, end product of the treatment process), which may constitute a risk factor whenattempting to utilize them economically. The research paper concentrates on determining the TTMSS fly ash heavymetal leaching level. For this purpose, ash samples were subjected to leaching with the batch and percolation tests,and the heavy metal content in eluates was determined by the FAAS method. The obtained results served as a base to determine the level of heavy metal immobilization in the ash, the element release mechanism (percolation test),and the impact of the L/S (liquid to solid) ratio and pH on the heavy metal leaching intensity (percolation test).The conducted research indicated high immobilization of heavy metals in TTMSS fly ash, regardless of the appliedstudy method, which corresponds to the results of other researchers. Lead was the most intensively eluted metal.

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Mariusz Rogulski , Artur Jerzy Badyda

This article presents a long-term evaluation of low-cost particulate matter (PM) sensors in a field measurements campaign. Evaluation was performed in two phases. During the first five months of the campaign, two PM sensors were simultaneously compared with the results from the reference air quality monitoring station in various atmospheric conditions—from the days with freezing cold (minimum temperature below −10 °C) and high relative humidity (up to 95%) to the days with the maximum temperature above 30 °C and low relative humidity (at the level of 25%). Based on the PM10 measurements, the correlation coefficients for both devices in relation to the reference station were determined (r = 0.91 and r = 0.94, respectively), as well as the impact of temperature and relative humidity on measurements from the low-cost sensors in relation to the reference values. The correction function was formulated based on this large set of low-cost PM10 measurements and referential values. The effectiveness of the corrective function was verified during the second measurement campaign carried out in the city of Nowy Sącz (located in southern Poland) for the same five months in the following year. The absolute values of the long-term percentage errors obtained after adjustment were reduced to a maximum of about 20%, and the average percentage errors were usually around 10%.

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Edward Majewski , Anna Wiktoria Komerska , Jerzy Kwiatkowski , Agata Malak-Rawlikowska , Adam Wąs , Piotr Sulewski , Marlena Goła , Kinga Pogodzinska , Jean-Loup Lecoeur , Barbara Tocco , Áron Török , Michele Donati , Gunnar Vittersø

Improving the eco-efficiency of food systems is one of the major global challenges faced by the modern world. Short food supply chains (SFSCs) are commonly regarded to be less harmful to the environment, among various reasons, due to their organizational distribution and thus the shortened physical distance between primary producers and final consumers. In this paper, we empirically test this hypothesis, by assessing and comparing the environmental impacts of short and long food supply chains. Based on the Life Cycle Assessment (LCA) approach, we calculate eco-efficiency indicators for nine types of food distribution chains. The analysis is performed on a sample of 428 short and long food supply chains from six European countries. Our results indicate that, on average, long food supply chains may generate less negative environmental impacts than short chains (in terms of fossil fuel energy consumption, pollution, and GHG emissions) per kg of a given product. The values of eco-efficiency indicators display a large variability across analyzed chains, and especially across different types of SFSCs. The analysis shows that the environmental impacts of the food distribution process are not only determined by the geographical distance between producer and consumer, but depend on numerous factors, including the supply chain infrastructure.

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Ryszard Zwierzchowski , Marcin Wołowicz

The paper contains a simplified energy and exergy analysis of pumps and pipelines system integrated with Thermal Energy Storage (TES). The analysis was performed for a combined heat and power plant (CHP) supplying heat to the District Heating System (DHS). The energy and exergy efficiency for the Block Part of the Siekierki CHP Plant in Warsaw was estimated. CHP Plant Siekierki is the largest CHP plant in Poland and the second largest in Europe. The energy and exergy analysis was executed for the three different values of ambient temperature. It is according to operation of the plant in different seasons: winter season (the lowest ambient temperature Tex = −20 °C, i.e., design point conditions), the intermediate season (average ambient temperature Tex = 1 °C), and summer (average ambient temperature Tex = 15 °C). The presented results of the analysis make it possible to identify the places of the greatest exergy destruction in the pumps and pipelines system with TES, and thus give the opportunity to take necessary improvement actions. Detailed results of the energy-exergy analysis show that both the energy consumption and the rate of exergy destruction in relation to the operation of the pumps and pipelines system of the CHP plant with TES for the tank charging and discharging processes are low.

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Grzegorz Wierzbicki , Mateusz Grygoruk , Maria Grodzka-Łukaszewska , Piotr Bartold , Tomasz Okruszko

The advances and retreats of ice sheets during Pleistocene significantly changed high- and mid-latitude landscapes and hydrological systems, albeit differently, in North America and Europe. On the southern margin of the Last Glacial Maximum (LGM) in the Baltic Sea basin, a specific type of valley has developed between glacial margins and upland or mountain slopes. We studied new geological data (boreholes, electrical resistivity imaging (ERI) from this geomorphic setting in Northeast Poland to understand: (1) how the landscape and river network evolved to eventually produce peat mires during the Holocene, and (2) the nature of groundwater recharge to fens in the upper Biebrza Valley. We present the results on a geological cross-section with hydrogeological interpretation. We also discuss regional geomorphology. In addition, we present the LGM extent derived from a spatial distribution of Vistulian (Weichselian) terminal moraines. These end moraines are also interpreted as Saalian kames. Thus, we additionally present another method of LGM extent delineation from a physicogeographical division. We link the steep slopes of the studied valley walls (kame terrace fronts) with thermokarst erosion in the periglacial zone. We then document the hydrogeological window (DISCONTINUITY in the till layer over the confined aquifer), which enables the outflow of groundwater into the peat bog. Although minerotrophic fen mire development in the study area is likely to be sustained in the near future through sufficient groundwater supply, the projected capture of the Biebrza River by the Neman River will not allow for sustaining peatland development.

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Anna Rolewicz-Kalińska , Krystyna Lelicińska-Serafin , Piotr Manczarski

Densely populated areas with large incoming populations have difficulty achieving high separate collection rates of municipal solid waste. The manuscript analyzes the link between biowaste collection and circular economy requirements as a fulfilment of the recycling rates and using biogas as a sustainable energy source. Three biowaste collection scenarios and three technical scenarios for its treatment are considered. The first scenario assumes only composting for biowaste treatment, the next includes also anaerobic digestion. In the years 2020–2050, the separate biowaste collection level will increase, depending on the scenario, from 26.9 kg/inh. up to 148.1kg/inh. By 2030, the quantity of biogas generated from biowaste can grow to almost 9 million m3/year, enabling the production of renewable energy at annual levels of almost 17 GWh and 69 TJ. Using the third scenario, the quantity of biogas generated grows more than twice (in 2035). If the capture rate of biowaste increases from 15% to 20% and then to 25%, the quantity of biogas generated grows by, respectively, 65% and more than 100%. Unfortunately, none of the scenarios enables the required municipal solid waste recycling rates in 2030 (60%) and 2035 (65%), which demonstrates the significant need to develop more effective separate collection systems, including biowaste. Methodology applied in the paper can be used for other cities and regions trying to meet circular economy demands.

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Andrzej Białowiec , Jakub Pulka , Marzena Styczyńska , Jacek A. Koziel , Joanna Kalka , Marcelina Jureczko , Ewa Felis , Piotr Manczarski

Improved technologies are needed for sustainable management of sewage sludge (SS). The torrefaction (also known as biomass “roasting”) is considered a pretreatment of SS before use in agriculture. However, it is not known whether the torrefaction has the potential to decrease heavy metals’ (HMs) leachability and the SS toxicity. Thus, the aim of the study was to evaluate the influences of the SS torrefaction parameters (temperature and process time) on HM contents in biochar, HM leachability, and biochar toxicity, and compare them with raw SS. The experiments were designed in 18 combinations (six temperatures, 200, 220, 240, 260, 280, and 300 °C; and three process times—20, 40, 60 min). Standard tests were used to determine HMs content, leachability, and toxicity. Results indicated that the torrefaction did not increase (p < 0.05) the HM content in comparison to the raw SS. The leachability of Zn, Ni, Cu, Cr, and Mn from SS biochars was similar to raw SS. However, the degree of leachability varied significantly (p < 0.05) from as low as 0.1% for Cu to high as 16.7% for Cd. The leachability of Cd (<16.7%) and Pb (<11.9%) from biochars was higher than from raw SS (<6.1% and <2.4%, respectively). The leachability of Cd from SS biochar, in five torrefaction combinations, was higher than the threshold value for hazardous waste. It is recommended that site-specific decisions are made for torrefaction of SS with respect to its HM content, as the resulting biochar could be considered as hazardous waste, depending on the feedstock. Moreover, the biochar produced under the whole range of temperatures during 20 min retention time significantly (p < 0.05) increased the Daphnia magna Straus mobility inhibition by up to 100% in comparison to the biochar obtained during 40 and 60 min torrefaction. Taking into account the increased leachability of specific HMs and D. magna Straus mobility inhibition, biochar should be considered a potentially hazardous material. Future research should focus on biochar dosage as a fertilizer in relation to its toxicity. Additional research is warranted to focus on the optimization of SS torrefaction process parameters affecting the toxicity.

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Andrzej J. Osiadacz , Maciej Chaczykowski

The role of modeling and simulation in development and operational planning of gas distribution networks is crucially important for system designers and operators, since it allows to get a detailed knowledge of the hydraulic properties of the network. The challenges in simulation of gas distribution networks are usually that of computational efficiency of the methods due to large dimensionality of the simulated networks, though it can also be related to flexible incorporation of the peripheral equipment (e.g., valves, compressors, pressure, and flow regulators) into the network model. Today, however, new challenges emerge as a consequence of market changes facing the gas industry in a multienergy system environment. These changes are expected to bring about significant fluctuations and uncertainty in distributed gas supply and demand as a consequence of increased gas-to-power activities, and a number of decentralized entry points, where deliveries of both liquefied natural gas (LNG) and renewable gases, such as hydrogen and synthetic methane, can be achieved. In this article, technical challenges related to problems with maintaining a stable overall gas distribution system with growing diversification of gas quality combined with gas trading activities (nominations and allocations) in units of energy rather than volume are addressed. Models and selected methods of steady state and transient analysis of gas networks relevant to the ongoing discussion in the field of multienergy systems are considered. The simulation problems of a real large-scale gas distribution network are presented and discussed.

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Anna Gnida, Monika Żubrowska-Sudoł, Katarzyna Sytek-Szmeichel, Jolanta Podedworna, Joanna Surmacz-Górska, Dorota Marciocha

Background The study aimed to evaluate the influence of the duration times of anaerobic phases on the bacterial biocenosis characterisation while denitrifying dephosphatation in the Integrated Fixed-Film Activated Sludge – Moving-Bed Sequencing Batch Biofilm Reactor (IFAS-MBSBBR). The experiment was conducted in a laboratory model. The study consisted of four series, which differed in terms of the ratio of the anaerobic phases. duration concerning the overall reaction time in the cycle. The anaerobic phases covered from 18 to 30% of the whole cycle duration. During the reactor performance that took 9 months, the influent and effluent were monitored by analysis of COD, TKN, NH4-N, NO2-N, NO3-N, TP, PO4-P, pH, alkalinity and the phosphorus uptake batch tests. Characterisation of the activated sludge and the biofilm biocenosis was based on fluorescent in situ hybridisation (identification of PAO and GAO) and the denaturing gradient gel electrophoresis patterns. Results The organic compounds removal was high (more than 95.7%) independently of cycle configuration. The best efficiency for nitrogen (91.1%) and phosphorus (98.8%) removal was achieved for the 30% share of the anaerobic phases in the reaction time. Denitrifying PAO (DPAO) covered more than 90% of PAO in the biofilm and usually around 70% of PAO in the activated sludge. A substantial part of the polyphosphate accumulating organisms (PAO) community were Actinobacteria. The denitrifying dephosphatation activity was performed mainly by Accumulibacter phosphatis. Conclusions High nutrient removal efficiencies may be obtained in IFAS-MBSBBR using the denitrifying dephosphatation process. It was found that the length of anaerobic phases influenced denitrification and the biological phosphorus removal. The extension of the anaerobic phases duration time in the reaction time caused an increase in the percentage share of denitrifying PAO (DPAO) in PAO. The biocenosis of the biofilm and the activated sludge reveal different species patterns and domination of the EBPR community.

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Radosław Żyłka , Wojciech Dąbrowski , Paweł Malinowski , Beata Karolinczak

The intensification of biological wastewater treatment requires the high usage of electric energy, mainly for aeration processes. Publications on energy consumption have been mostly related to municipal wastewater treatment plants (WWTPs). The aim of the research was to elaborate on models for the estimation of energy consumption during dairy WWTP operation. These models can be used for the optimization of electric energy consumption. The research was conducted in a dairy WWTP, operating with dissolved air flotation (DAF) and an activated sludge system. Energy consumption was measured with the help of three-phase network parameter transducers and a supervisory control and data acquisition (SCADA) system. The obtained models provided accurate predictions of DAF, biological treatment, and the overall WWTP energy consumption using chemical oxygen demand (COD), sewage flow, and air temperature. Using the energy consumption of the biological treatment as an independent variable, as well as air temperature, it is possible to estimate the variability of the total electric energy consumption. During the summer period, an increase in the organic load (expressed as COD) discharged into the biological treatment causes higher electric energy consumption in the whole dairy WWTP. Hence, it is recommended to increase the efficiency of the removal of organic pollutants in the DAF process. An application for the estimation of energy consumption was created.

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Jerzy Sowa

Almost all inhabitants of developed countries spend the majority of their time in buildings. Therefore, high expectations regarding the environment of the rooms they occupy should not surprise anyone. These expectations are addressed basically by architects and HVAC engineers. Surprisingly, more or less consciously, they try to reproduce the microclimate of the African savanna.

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Anna Sosnowska

The investigation focused on the non-migrating mid-channel bars that emerged in the river channel as a consequence of river engineering. A reach of around 280 km of Middle Vistula River (Poland) was taken into account as the study site. The most vivid examples of the river engineering works potentially influencing the river channel are the ferry crossings. Along the Middle Vistula River reach, there are 17 ferry crossings that were constructed from 1970s to 1990s. A cartographic analysis was carried out to determine the influence of the ferry crossing construction over the river channel. It was performed on the basis of aerial photographs (traditional aerial photography and UAV photography). In 3 out of 17 potential localizations, the emergence of large non-migrating mid-channel bars was observed. A study of cartographic materials (from 1950s to 2000s) allowed determination of the dynamics of those bars, including time of emergence and the changes of their size.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafin

Municipal waste treatment is inherently associated with odour emissions. The compounds characteristic of the processes used for this purpose, and at the same time causing a negative olfactory sensation, are organic and inorganic sulphur and nitrogen compounds. The tests were carried out at the waste management plant, which in the biological part, uses the methane fermentation process and is also equipped with an installation for the collection, treatment, and energetic use of biogas. The tests include measurements of the four odorant concentrations and emissions, i.e., volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulphide (H2S), and methanethiol (CH3SH). Measurements were made using a MultiRae Pro portable gas detector sensor. The tests were carried out in ten series for twenty measurement points in each series. The results show a significant impact of technological processes on odorant emissions. The types of waste going to the plant are also important in shaping this emission. On the one hand, it relates to the waste collection system and, on the other hand, the season of year. In addition, it has been proved that the detector used during the research is a valuable tool enabling the control of technological processes in municipal waste processing plants.

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Tomasz Owczarek , Mariusz Rogulski , Piotr O. Czechowski

The aim of the work is to demonstrate the possibility of building models to correct the results of measurements of particulate matter PM10 concentrations obtained using low-cost devices. Such devices apply the optical method to values comparable with those obtained using the reference gravimetric method. An additional goal is to show that the results corrected in this way can be used to carry out the procedure for testing equivalence of these methods. The study used generalized regression models (GRMs) to construct corrective functions. The constructed models were assessed using the coefficients of determination and the methodology of calculating the measurement uncertainty of the device. Measurement data from the two tested devices and the reference method were used to estimate model parameters. The measurement data were collected on a daily basis from 1 February to 30 June 2018 in Nowy Sącz. Regression allowed building multiple models with various functional forms and very promising statistical properties as well as good ability to describe the variability of reference measurements. These models also had very low values of measurement uncertainty. Of all the models constructed, a linear model using the original PM10 concentrations from the tested devices, air humidity, and wind speed was chosen as the most accurate and simplest model. Apart from the coefficient of determination, expanded relative uncertainty served as the measure of quality of the obtained model. Its small value, much lower than 25%, indicates that after correcting the results it is possible to carry out the equivalence testing procedure for the low-cost devices and confirm the equivalence of the tested method with the reference method.

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Katarzyna Anna Affek , Adam Muszyński , Monika Załęska-Radziwiłł , Nina Doskocz , Aleksandra Ziętkowska , Marcin Widomski

Treated wastewater may be a valuable source of water and/or nutrients for crop production and fish farming. Disinfection of treated wastewater should be performed to protect water resources against pathogenic and opportunistic microorganisms, as well as micropollutants contained in effluents. However, in the case of ozonation of treated wastewater, a large portion of contaminants do not undergo complete mineralization and can be transformed into by-products of unknown toxicity. The research performed in this study by culture-dependent and independent methods showed that the inactivation of bacteria in treated wastewater by ozonation does not take place effectively and may depend on the presence of other contaminants that may first react with the disinfectant. Some bacterial cells proved to be damaged by a disinfectant to the extent that they were unable to grow on nutrient media, but they were still viable and potentially posing a sanitary threat. Possible reasons for the disinfection failure were investigated and discussed. Ecotoxicity tests with algae Desmodesmus quadricauda, crustacean Daphnia magna, and bacteria Aliivibrio fischeri showed that by-products may be formed during ozonation of treated wastewater which is toxic to aquatic organisms. The toxicity class of treated wastewater may change from the completely non-toxic to very high hazard category, and there is a clear relationship between the time of ozonation and the increase in ecotoxicity.

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Joanna Rucińska , Anna Wiktoria Komerska , Jerzy Kwiatkowski

The decarbonisation goal stated in the Energy Performance of Buildings Directive (EPBD) regarding the building sector will be achieved only if the whole building life-cycle is considered. To fulfil this requirement, a benchmark based on the life cycle assessment (LCA) must be integrated into the early planning phase of buildings by designers. The estimation of such indicators requires the development of a database of building assessments. In this study, an LCA of 11 office buildings in Poland was used to set average values that can be used as a benchmark. The LCA methodology based on the Building Research Establishment Environmental Assessment Method (BREEAM) certification was used. The analysis did not concentrate on one type of office building. The main objective was to investigate a possible range of total Global Warming Potential (GWP) index values normalized to the usable unit floor area. The importance of the GWP of individual life-cycle phases was also considered. The study shows that the used methodology is adequate for LCA benchmark estimation to set preliminary average values for office buildings in Poland.

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Marek Nawalany , Grzegorz Igor Sinicyn , Maria Grodzka-Łukaszewska , Dorota Mirosław-Świątek

Modelling of water flow in the hyporheic zone and calculations of water exchange between groundwater and surface waters are important issues in modern environmental research. The article presents the Analytical Hyporheic Flux approach (AHF) permitting calculation of the amount of water exchange in the hyporheic zone, including vertical water seepage through the streambed and horizontal seepage through river banks. The outcome of the model, namely water fluxes, is compared with the corresponding results from the numerical model SEEP2D and simple Darcy-type model. The errors of the AHF model, in a range of 11–16%, depend on the aspect ratio of water depth to river width, and the direction of the river–aquifer water exchange, i.e., drainage or infiltration. The AHF model errors are significantly lower compared to the often-used model based on vertical water seepage through the streambed described by Darcy’s law.

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Klaudia Weronika Pałaś, Jarosław Zawadzki

Deforestation is currently among the most critical ecological issues, which need to be addressed urgently. Hence, identification of effective environmental monitoring methods is of top priority, especially in locations where no precise ground-based data are available. Constant development of remote sensing technology provides an increasing number of tools needed for that purpose, based on extraction of information about Earth’s surface. One of the most advanced Earth Observation (EO) programs is Copernicus, established by European Space Agency (ESA). It incorporates a constellation of Sentinel satellites continuously delivering imagery, which can serve as input data for further environmental analyses. They can be performed in the Sentinel Application Platform (SNAP), the software also developed by ESA. The Sentinel-2 (S-2) mission was designed specifically for Earth’s surface observation. It acquires high-resolution data within visible and infrared range of electromagnetic spectrum (EMS), which has found applications in forest cover monitoring. In this paper, S-2 imagery was processed in SNAP software to determine its potential for deforestation observation on the example of 2017 tree logging in Białowieża Forest. For this purpose, images from October 2016 and 2018, covering the area of interest, were downloaded from the Copernicus Open Hub Platform. They then underwent pre-processing, involving atmospheric correction, resampling, and subset operations. As a part of environmental analysis, a set of chosen radiometric and biophysical indices was computed to preliminarily determine their usefulness for deforestation mapping. Index values were extracted from tree logging areas using pinpoints and region of interest (ROI) mask. The most effective indicators were the MERIS Terrestrial Chlorophyll Index (MTCI) and the Brightness Index (BI). The Normalized Difference Vegetation Index (NDVI), as well as the Ratio Vegetation Index (RVI), also displayed promising results. The results were visualized in Quantum GIS (QGIS) software, provided by the Open Source Geospatial Foundation (OSGeo).

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Monika Żubrowska-Sudoł , Aleksandra Dzido , Agnieszka Garlicka , Piotr Krawczyk , Michał Stępień , Katarzyna Umiejewska , Justyna Walczak , Marcin Wołowicz , Katarzyna Sytek-Szmeichel

The study objective was to adjust the hydrodynamic disintegrator dedicated to sewage sludge pre-treatment (HDS) to work with agricultural substrate. This involved the development and implementation of a mathematical model of flow via the device’s domain. An innovative disintegrator (HAD—hydrodynamic disintegrator for agriculture) was designed, built, and tested based on the obtained results. The main improvements to the HDS include the implementation of shredding knives in order to overcome clogging by crushed substrate, and the application of ribs in the recirculation zone, contributing to the development of an additional structure damage zone. The challenge of this study was also to determine the operating parameters of the HDA that would provide for an increase in methane production with positive energy balance. The testing procedures, for which maize silage was selected, involved batch disintegration tests and biochemical methane potential tests. No clogging of rotor or spontaneous shutting off of the device, in other words, problems that had occurred in the HDS, were observed. The applied pre-treatment method permitted an increase in the methane potential of maize silage by 34.4%, 27.0%, and 21.6%, respectively for samples disintegrated at energy densities of 10 kJ/L, 20 kJ/L, and 35 kJ/L with net energy profit.

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Katarzyna Maciejewska

The work presents the results of short-term health effects assessment of particulate matter (PM) in Warsaw, the capital of Poland. The influence of three PM fractions, PM10 (particles of aerodynamic diameter < 10 μm), PM2.5 (particles of aerodynamic diameter < 2.5 μm), and PMc (coarse fraction of diameter between 2.5 and 10 μm), modeled by the CALMET/CALPUFF system, has been studied in the period of 2013–2014. Six population health endpoints; daily counts of all-cause (ALL), cardiovascular (CV), and respiratory (RS) death cases; and ALL, CV, and RS hospital admissions were investigated with the use of statistical time series analysis via nonparametric generalized additive model (GAM) approach. The results show that PM2.5 increases the relative risk (RR) of ALL premature deaths by 0.7% per 10 μg/m3, as well as of CV mortality by 0.9%. PM10 exposures reveal the largest influence on mortality in a 2-day lag: 0.3% for all causes and 0.4% for CV causes, while for RS causes only in the elderly group (above 65 years, 1.4%) and for males (2.1%). The risk of hospitalizations increases with elevated PMc levels by 2.5%, 2.1%, and 4.6% for ALL, CV, and RS hospital admissions, respectively. The results suggest that the research on PM impact on health should concentrate more on attempts to assign specific health outcomes to PM originating from different types of sources, characterized by different granulation, as well as physical and chemical properties of emitted particles.

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Karol Michał Przeździecki , Jarosław Zawadzki

Estimation of soil moisture condition on a local or regional scale is one of the most important problems in vegetation conditions monitoring. One of the most suitable approach to do this over vegetated areas is the Land Surface Temperature – Vegetation Index (LST-VI) Triangle Method. This method estimates water content in soil which is available for plants in contrast to methods using satellite observations in the microwave band, and it is superior to pixel by pixel soil moisture methods using observations in the optical band which neglect statistical relationship between VI and LST controlling evapotranspiration on vegetated area. This study tested a methodological modification of the method based on assumption that evapotranspiration depends on the difference between the air temperature and the terrain surface temperature. The spatial distribution of Temperature-Vegetation Dryness Indices, which reflect soil moisture in the root zone was calculated for vast areas of Central Europe using the classic Triangle Method and its modified version. Both NDVI and EVI indices were used as input data in these calculations. The air temperature at 2 m height was taken from SYNOP reports, and the terrain surface temperature from MODIS data. In addition, Matlab scripts were written by the authors to allow convenient access to free SYNOP data. Our results indicate that proposed modification increases the accuracy of soil moisture estimation. This was confirmed by comparing classic and modified Temperature-Vegetation Dryness Indices values with rainfall data.

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Monika Żubrowska-Sudoł , Justyna Walczak , Agnieszka Garlicka , Katarzyna Sytek-Szmeichel , Katarzyna Umiejewska

The objective of the study was to verify whether the method of determining the efficiency of sewage sludge disintegration, i.e. the disintegration degree (DD), can also be used to assess agro-waste disintegration. The following types of agro waste were tested: remains of fruits, sugar beet pulp and sugar beet pulp in the form of pellets. It was shown that DD as used for sewage sludge can also be a useful tool in assessing the disintegration efficiency of agro waste, although it requires the following modifications: (a) a methodology of chemical hydrolysis for each type of agro waste in order to determine the total amount of soluble COD (SCOD) that can be released from the sample and (b) possible changes in the SCOD value that may occur in the sample left in ambient conditions for a time period corresponding to the duration of the disintegration process. DD of agro waste determined according to the formula adopted for sewage sludge resulted in a considerable overestimation of the value in comparison to the formula proposed by the authors, i.e. DD determined for an energy density of 35 kJ L−1 was higher by 55.9 ± 21.5%, and for an energy density of 140 kJ L−1 it was higher by as much as 73.8 ± 28.1%. Taking into account the differences in the determined disintegration degree values that result from the methodology of conducting the chemical hydrolysis, it is recommended, in order to assess the efficiency of disintegration of agro waste, to use the efficiency of organic compound release.

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Lech Gawuć, Maciej Krystian Jefimow, Karol Paweł Szymankiewicz, Magdalena Kuchcik, Anahita Sattari, Joanna Strużewska

Urban heat island (UHI) is one of the most distinctive characteristics of urban climate. The objective of this study is to apply a statistical modeling of the nocturnal atmospheric UHI based on the relationship between observed air temperature from ground stations and remotely sensed temperature of the urban surface. The goal of the approach is to limit input data for the developed modeling method in order to assure transferability of the methodology in different cities. Time series of surface temperature and normalized difference vegetation index are obtained from the MODIS instrument for a 10-year period (2008–2017). The air temperature is collected from the in-situ observational network of 21 stations. The studies are conducted for different locations with gradual changes in urbanization in order to assess the impact of urbanization on the relationship between simultaneous air and surface UHI. The urbanization is described by commonly available land cover metrics. Results showed that the proposed approach provides satisfactory AUHI modeling results for the locations with the least degree of urbanization. The best results are obtained with a simple linear regression model with the iterative procedure to minimize the mean absolute gross error (MAGE). The lowest MAGE for modeled UHI is 1.18 °C with 69% of the variance explained. The strongest linear relationship between simultaneous SUHI and AUHI is noted for those station pairs whose surroundings have the highest differences in urbanization, and the highest UHI intensities are observed. The strength of the SUHI/AUHI linear relationship decreases gradually with the increasing urbanization of the stations’ surroundings.

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Agnieszka Garlicka, Monika Żubrowska-Sudoł

The main objective of the study was the verification whether conducting the hydrodynamic disintegration (HD) of thickened excess sludge (TES) before the anaerobic hydrolysis (AH) can cause an increase in the efficiency of the hydrolysis process, and therefore a reduction in its duration, or allow for complete omission of the stage before the anaerobic digestion (AD). For this purpose, the HD (conducted in five levels of energy density (EL): 140, 280, 420, 560 and 700 kJ/L) of TES was carried out, and then all sludges (before and after disintegration) were subjected to the AH. The obtained results confirmed that the process of HD can be an effective method of increasing the solubilisation and bioavailability of TES. In the process of HD, the maximum increase in ΔVFA (308–428 mg VFA/L), was reported when EL was increased from 140 to 280 kJ/L (the solubilisation degree increased from approximately 2 to 8%). The obtained results also showed that the ΔSTN and ΔSTP were related to solubilisation degree. The most intensive increase in the ΔSTN was determined for solubilisation degree in a range of 15–20%. In the case of ΔSTP, constant intensity of release of the compounds to the sludge liquid was observed. The obtained results also confirmed that conducting the process of AH of disintegrated TES proved to change the SCOD value when contrasted with the value of this indicator at the start of the experiment (before hydrolysis): (i) the EL equal to 140 and 280 kJ/L allowed for a higher SCOD value; (ii) at EL higher or equal to 560 kJ/L it caused a decrease in the SCOD value.

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Joanna Rucińska, Adrian Trząski

This paper deals with the impact of the use of daylight on the overall energy demand for heating, cooling, and lighting in educational buildings. The energy performance of buildings is currently of the utmost importance as current European regulations, starting from 31st December 2020 impose that all new buildings must meet nearly zero-energy building requirements. This paper presents a study of the illuminance distribution in an educational room obtained from measurements and simulation results using two different models. One of the models, integrated with a thermal simulation software, was used to estimate the impact of daylight on the energy demand. The analysis included the use of various window types, lighting control system, reference point location, and daylight calculation model for a sample room in an educational building. Results of the analysis indicate that, due to the high share of lighting demand (reaching up to 78% of the primary energy balance), there is a need to take into account the efficiency of lighting systems during the design process to correctly determine the actual energy balance of a building, increase the quality of the design of lighting systems, as well as to select the optimal parameters of windows.

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Agnieszka Garlicka, Monika Zubrowska-Sudol, Katarzyna Umiejewska, Otton Roubinek, Jacek Palige, Andrzej Chmielewski

The main purpose of this study was the assessment of the possibility of increasing the production of biogas through the pre-treatment of thickened excess sludge (TES) by means of the hydrodynamic cavitation (HC) conducted at different levels of energy density (EL) i.e., 70, 140 and 210 kJ/L. The experiments were performed on a pilot scale, and a mixture of thickened primary sludge (TPS) and TES was used as digester feed. The results documented that an important parameter determining the possibility of obtaining an enhanced methane production is the value of energy input in the HC process. This parameter determines the changes occurring in sludge as a result of disintegration (i.e., sludge floc deagglomeration, lysis of cells, re-flocculation process and the related release of compounds susceptible to biodegradation from sludge flocs). The maximum increase in methane yield (MY) of 152% was obtained for EL = 140 kJ/L. In this case, HC mainly caused sludge floc deagglomeration. An increase in MY was also recorded when TES was subject to the disintegration process at EL = 210 kJ/L. However, it was 4.3 times lower than that observed for EL = 140 kJ/L. Pre-treatment of TES at EL = 70 kJ/L did not contribute to an increase in methane production.

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Nina Doskocz , Monika Załęska-Radziwiłł , Katarzyna Anna Affek , Maria Lucyna Łebkowska

In the literature, there are few ecotoxicological data concerning the effects of nanoparticles on reducers, which are an important element of the food chain in aquatic ecosystems. The work aimed to evaluate the influence of two types of engineering nanoparticles: aluminum oxide (nano-Al2O3) and zirconium oxide (nano-ZrO2) on micro-organisms. In this work enzymatic assay (bioluminescence test) with Vibrio fischeri was performed as well as two growth tests: test with Pseudomonas putida and test microbial assay for toxic risk assessment with 10 species of bacteria and 1 species of fungi). In this study, the effect of the activity of nano-Al2O3 and nano-ZrO2 on micro-organisms as compared to their bulk counterparts. The obtained values of concentrations of EC50 and no observed effect concentrations showed a different sensitivity of the organisms to the examined compounds. According to the European Union criteria, nano-Al2O3 was very toxic to P. putida (EC50 = 0.5 mg/L), while nano- ZrO2 was harmful to Pichia anomala (EC50 = 89.80 mg/L) and P. putida (EC50 = 25.4 mg/L). Nanoparticles proved to be more toxic to tested micro-organisms than their bulk counterparts. This indicates that the nano-form of a given substance may pose a greater hazard for the environment than the same substance in the large form.

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B. Kubat , Marian Kwietniewski

In the study, the authors have attempted to develop a failure rate prediction model for a selected water supply network using linear regression, taking into account the simultaneous impacts of many factors on the failure rate; also, possible methods of failure rate visualization for the examined network were presented. In the regression model, the dependent variable is the unit failure frequency (fail/(km year)), whereas independent variables (explaining this frequency) are: pipe material, age and diameter, soil type (impermeable, permeable) and soil moisture content (dry, wet). Statistical analyses have shown that the failure rate of the examined water supply network is affected only by soil conditions. Spatial distribution of the failure number and frequency was visualized, paying special attention to the parts of the network where the spatial concentration of failures was the greatest.

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Katarzyna Juda-Rezler, Magdalena Reizer, Katarzyna Maciejewska, Barbara Błaszczak, Krzysztof Klejnowski

For the purposes of this work, a first in Poland, full-year collection of daily PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 μm) samples was chemically analyzed to determine the contents of elemental and organic carbon, water-soluble inorganic ions and 21 minor and trace elements in PM in an urban background site in Warsaw. Annual mean PM2.5 concentration reached 18.8 μg/m3, with the lowest levels in summer (11.5 μg/m3 on average) and the highest in winter (27.5 μg/m3), with several episodes reaching over 80 μg/m3. Strong seasonal differences were observed mainly for the contents of nitrate and secondary organic carbon (SOC), while sulphate showed the least variability. Secondary species constituted on average 45% of PM2.5 mass, suggesting large influence of regional and long-range transport of pollutants. Source apportionment with the use of positive matrix factorization (PMF) method, supported by the analysis of enrichment factors, led to identification of six main sources of PM2.5 origin: residential combustion (fresh & aged aerosol) (46% of PM2.5 mass), traffic exhaust (21%) and non-exhaust (10%) emissions, mineral dust/construction works (12%), high-temperature processes (8%) and steel processing (3%). Including primary organic carbon (POC) and SOC as two separate constituents helped to distinguish between the primary and secondary sources of the aerosol. The identification of sources was also supported by investigating their yearly and weekly profiles, as well as the correlation of PM constituents with meteorological conditions, which are one of the main drivers of heat generation activities. We found that the most distinctive markers of PM sources in Warsaw are SOC, Cl and As for residential combustion, NH4+, Sb and POC for road transport, Ca and Mg for construction works and SO42− for long-range transport of PM.

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Monika Załęska-Radziwiłł , Nina Doskocz , Katarzyna Anna Affek , Adam Muszyński

The study examined structural and functional changes in the microcosm, inhabited by representatives of all trophic levels of the aquatic food chain, in the presence of aluminum oxide nanoparticles and their bulk counterparts (100 mg/L). The 28 d experiment showed negative effects of nano-Al2O3 on aquatic ecosystems, as evidenced by reduced biodiversity of microbenthic and plankton organisms. Furthermore, exposure to nanoparticles contributed to the increase of the activity of antioxidative enzymes of benthos. Cytochemical analysis of Daphnia magna crustacean cells showed accumulation of nanoparticles on the surface of organisms and in their mitochondria, causing swelling of mitochondrial cristae, as well as disturbances of their system with a clear matrix in the centre of organelles. However, there were no significant changes in microcosms with bulk counterparts of nanoparticles, as well as no accumulation of aluminum oxide on the surface, nor in the mitochondria of D. magna, was detected.

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Joanna Rotnicka, Maciej Dłużewski, Maciej Dąbski, Mirosław Rodzewicz, Wojciech Włodarski & Anna Zmarz

Recent developments in unmanned aerial vehicles (UAVs) have resulted in high-resolution digital elevation models (DEMs) of vulnerable coastal environments, including beach–foredune topography. If performed repetitively, they can offer an excellent tool to determine the spatial and temporal changes in the sediment budget, which may be required for proper land management. However, the quality of a UAV, slope parameters, and vegetation significantly influence DEM accuracy. The aim of this study is to compare precise GPS-RTK transects across a section of the South Baltic coast in Poland with those obtained from a DEM based on high-resolution and high-accuracy images obtained by a wind-resistant, high-quality fixed-wing UAV during beyond visual line of sight operation (BVLOS). Different land cover classes, slope inclination, and general curvature, as well as surface roughness, were taken into consideration as possible factors influencing the uncertainty. The study revealed that marram grass greatly affects the accuracy of the UAV-derived model and that the uncertainty of the UAV-derived DEM increases together with increasing slope inclination and, to a lesser degree, with increasing general slope curvature. We showed that sediment budget determinations with the use of a UAV-based DEM are correct only where grass cover is sparse, in our study, up to 20% of the area.

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Maria Teresa Markiewicz

Since the 1990s, there have been trends in Central and Eastern European countries to reduce water consumption. This phenomenon is closely related to the political, social and economic changes in these countries and the introduction of economic instruments in water management. The article presents the changes in water consumption in households in the years 1950–2019 depending on the degree of equipping buildings with sanitary facilities, and the structure of water consumption for particular purposes. For the same period, the quality of sewage generated in households is presented on the basis of bibliography. The content of total suspended solids was the main analysed parameter. The last part of the article presents the quality of wastewater discharged to fourteen Polish wastewater treatment plants. The majority of the analysed plants show an increase in the concentration of total suspended solids in the domestic sewage discharged to them. This phenomenon may be influenced by the decreasing water consumption in households.

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Vishakh Vadakkedath, Jarosław Zawadzki, Karol Przeździecki

On-site monitoring in large areas located in inaccessible regions can be difficult and costly. Thus remote sensing is an essential tool for mapping and monitoring changes in such regions. Therefore, this paper describes long-term multisensory satellite observations of the expansion of the Batagaika crater in Northern Siberia and natural succession of vegetation in its interior from 1991 to 2018. Landsat 5 TM, Landsat 7 + ETM, Landsat 8 OLI/TIRS imageries were mainly used as a data source for analyses, although Sentinel-2A imagery and DEM image from ASTER satellite were also employed for calculating a vegetation index and expansion in the crater area. The observations were conducted in years 1991–2018 and were made in a summer season. The results reveal that the crater area increased by almost three times during these 27 years and that the fastest expansion took place between 2010 and 2014 with 22.7% increment. The analysis of elevation of the crater revealed that in 2018 its maximum depth was ca 70 m and that depth was decreasing towards its north-east tail. Additionally, the satellite imagery of land surface temperature which is a driving force of crater expansion was visualized for chosen hot days within the time frame 2010–2018. The study of temporal and spatial changes in NDVI spatial distributions inside the crater revealed also a high rate of the succession of vegetation, which may reduce melting of permafrost inside the Batagaika crater and its further expansion.

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Elżbieta Kubrak, Janusz Kubrak, Adam Kiczko, Michał Kubrak

This study analyzes the possibilities of using an irrigation sluice gate in submerged conditions to measure water flow rate. Hydraulic experiments on sluice gate discharge capacity were performed on a model made on a 1:2 scale. Measurements were taken for the submerged flow of the sluice gate. Nomograms and relationships for discharge coefficients of the analyzed sluice gate were developed. The possibility of using the existing nomogram for discharge capacity of the submerged sluice gate to determine the discharge capacity of the modeled gate was also investigated. The effect of narrowing of the sluice gate cross-section resulting from different mounting techniques on its capacity was explained. The analyses confirmed the possibility of using the formulas for the submerged sluice gate to estimate the flow through the irrigation sluice gate.

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Mirosław Maziejuk , Wiesław Lisowski , Tomasz Sikora , Łukasz Osuchowski , Jerzy Sowa , Jacek Hendiger , Halina Kamińska

Three species of ornamental plants (Sansevieria trifasciata, Epipremnum aureum, Dieffenbachia seguine) were used to improve the quality of the air in workplaces. The lab. tests confirmed removal of volatile org. comp. A new measurement techn. enabling continuous monitoring of the quality of the air in spaces was developed.

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F.E.Uilhoorn

Accurate and efficient simulation of the hydraulic shock phenomenon in pipeline systems is of paramount importance. Even though the conservation-law formulation of the governing equations is here strongly advocated, the nonconservative form is still frequently used. This also concerns its mathematical conservative form. We investigated the numerical consequences of using the compressible gas flow model in the latter form while simulating a hydraulic shock. In this context, we also solved two Riemann problems. For the investigation, we used the third-, fifth- and seventh-order accurate weighted essentially non-oscillatory (WENO) scheme along with the Lax–Friedrichs solver at the cell interfaces. Both the classical finite volume WENO scheme and its modification WENO–Z have been implemented. A procedure based on the method of manufactured solutions has been developed to verify whether the numerical code solved correctly the hyperbolic set of equations. We demonstrated that the solutions of the conservative and nonconservative formulations are similar if we have smooth variations in the solution domain. The convective inertia term in the momentum equation should not be ignored. In the presence of shocks, differences in oscillating behavior and slope steepness near the discontinuities were observed. For the hydraulic shock problem, spurious oscillations appeared while using the nonconservative formulation in combination with the WENO–Z reconstruction.

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Jakub Pulka , Piotr Manczarski , Paweł Stepien , Marzena Styczyńska , Jacek A. Koziel , Andrzej Białowiec

Sewage sludge (SS) recycling is an important part of the proposed ‘circular economy’ concept. SS can be valorized via torrefaction (also known as ‘low-temperature pyrolysis’ or ‘roasting’). SS can, therefore, be considered a low-quality fuel or a source of nutrients essential for plant growth. Biochar produced by torrefaction of SS is a form of carbonized fuel or fertilizer. In this research, for the first time, we tested the feasibility of torrefaction of SS with high ash content for either fuel or organic fertilizer production. The research was conducted in 18 variants (six torrefaction temperatures between 200~300 °C, and three process residence times of 20, 40, 60 min) in 5 repetitions. Fuel and fertilizer properties and multiple regression analysis of produced biochar were conducted. The higher heating value (HHV) of raw SS was 21.2 MJkg-1. Produced biochar was characterized by HHV up to 12.85 MJkg-1 and lower H/C and O/C molar ratio. Therefore, torrefaction of SS with high ash content should not be considered as a method for improving the fuel properties. Instead, the production of fertilizer appears to be favorable. The torrefaction increased C, N, Mg, Ca, K, Na concentration in relation to raw SS. No significant (p < 0.05) influence of the increase of temperature and residence time on the increase of biogenic elements in biochar was found, however the highest biogenic element content, were found in biochar produced for 60 min, under the temperature ranging from 200 to 240 °C. Obtained biochars met the Polish regulatory criteria for mineral-organic fertilizer. Therefore SS torrefaction may be considered a feasible waste recycling technology. The calculation of torrefaction energy and the mass balance shows energy demand <2.5 GJMg-1 w.m., and the expected mass yield of the product, organic fertilizer, is ~178 kgMg-1 w.m of SS. Further investigation should consider the scaling-up of the SS torrefaction process, with the application of other types of SSs.

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Małgorzata Wojtkowska

The study aimed to assess the content of metals in water, suspended solids and bottom sediments sampled from the Wilanowskie Lake. The analyses of zinc, lead, cadmium, and copper showed that the metal concentration in water, suspended solids, and sediments differed at individual measurement points. It can be attributed to the influx of pollutants from the areas adjacent to the lake. During the sampling period, the concentration of dissolved forms of Cu varied from 33.1 to 186.5 μg/dm3; in the suspended form it ranged from 0.21 to 0.81 mg/dm3, and in bottom sediments, it was in the range 17–245 mg/kg dw. For cadmium, the concentration of dissolved forms ranged from 1.15 to 19.53 μg/dm3, in suspended form – from 0.02 to 0.1 mg/dm3, and in the sediments from 6.2 to 21.6 mg/kg dw. The concentration of dissolved forms of lead was from 3.19 to 106.7 μg/dm3, in the suspension from about 0.67 to 1.07 mg/dm3 and in sediments – from 200 to 450 mg/kg dw. For zinc, the results were respectively: from 65 to 632 μg/dm3 for the metal forms dissolved in water, from 1.1 to 2.2 mg/dm3 for suspended forms and from 70 to 2,900 mg/kg dw in sediments.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafin

Biogas plants processing municipal waste are an important part of a circular economy (energy generation from biogas and organic fertiliser production for the treatment of selectively collected biowaste). However, the technological processes taking place may be associated with odour nuisance. The paper presents the results of pilot research conducted at six municipal waste biogas plants in Poland. It shows the relations between odour intensity and concentration and the occurring meteorological and ambient conditions (air temperature and relative humidity) and technological factors at biogas plants processing municipal waste. The impact of meteorological and ambient conditions was identified by measuring air temperature and relative humidity and observing their changes. The impact of technological factors was identified by measuring odorant concentration (volatile organic compounds and ammonia) and observing their changes between individual measurement series. At most analysed biogas plants, the influence of technological factors on odour emissions took place and was clearly noted. The elements of biogas installations characterised by the highest concentration of these odorants were indicated. Special attention should be paid to the choice of technological solutions and technical and organisational measures to reduce the impact of unfavourable atmospheric conditions on odour emissions.

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Agnieszka Malesińska, Mariusz Wojciech Rogulski, Pierfabrizio Puntorieri, Giuseppe Barbaro, Beata Elżbieta Kowalska

The purpose of this study is to analyze the effect that inserting an elastic tube into a pressure pipeline has on the water hammer phenomenon. This research draws upon theoretical analysis, experimental testing, and numerical simulations. Assuming perfect elastic behavior of the system, the formula for the constant pressure wave velocity in a pipeline with an inserted tube was derived. Experimental tests were carried out, aimed at reducing the pressure increase in the pipeline due to inserting a silicone rubber tube in it. A significant reduction of the pressure increase has been achieved. Theoretical values of the pressure wave velocity were significantly lower than measured. Numerical calculations were performed, the purpose of which was to simulate the course of pressure changes in the pipeline with inserted tube. An approximate model of unsteady flow was used, which relates elastic behavior of water, pipeline, and tube materials to the continuity equation via the variable pressure wave velocity. By taking into account the variable celerity of the pressure wave and diffusive term, it was possible to obtain an acceptable compliance between the experimental data and the results of the numerical calculations.

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Michał Kubrak, Apoloniusz Kodura

The purpose of this study is to analyze the effect that inserting an elastic tube into a pressure pipeline has on the water hammer phenomenon. This research draws upon theoretical analysis, experimental testing, and numerical simulations. Assuming perfect elastic behavior of the system, the formula for the constant pressure wave velocity in a pipeline with an inserted tube was derived. Experimental tests were carried out, aimed at reducing the pressure increase in the pipeline due to inserting a silicone rubber tube in it. A significant reduction of the pressure increase has been achieved. Theoretical values of the pressure wave velocity were significantly lower than measured. Numerical calculations were performed, the purpose of which was to simulate the course of pressure changes in the pipeline with inserted tube. An approximate model of unsteady flow was used, which relates elastic behavior of water, pipeline, and tube materials to the continuity equation via the variable pressure wave velocity. By taking into account the variable celerity of the pressure wave and diffusive term, it was possible to obtain an acceptable compliance between the experimental data and the results of the numerical calculations.

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C.A.Belis, D. Pernigotti, G.Pirovano, O.Favez, J.L.Jaffrezo, J.Kuenen, H.Denier van Der Gon, M.Reizer, V.Riffault, L.Y.Alleman, M.Almeida, F.Amato, A.Angyal, G.Argyropoulos, S.Bande, I.Beslic, J.-L.Besombes, M.C.Bove, P.Brotto, G.Calori, D.Cesari, C.Colombi, D.Contini, G.De Gennaro, A.Di Gilio, E.Diapouli, I.El Haddad, H.Elbern, K.Eleftheriadis, J.Ferreira, M. Garcia Vivanco, S.Gilardoni, B.Golly, S.Hellebust, P.K.Hopkea, Y.Izadmaneshia, H.Jorqueraa, K.Krajsek, R.Kranenburg, P.Lazzeria, F.Lenartza, F.Lucarelli, K.Maciejewska, A.Manders, M.Manousakas, M.Masiola, M.Mirceaa, D.Mooibroeka, S.Navaa, D.Oliveirac, M.Paglioney, M.Pandolfi, M.Perronea, E.Petraliaa, A.Pietrodangeloa, S.Pillona, P.Pokornaa, P.Prati, D.Salameh, C.Samara, L.Sameka, D.Saraga, S.Sauvage, M.Schaap, F.Scottoa, K.Sega, G.Sioura, R.Tauler, G.Vallia, R.Vecchia, E.Venturinia, M.Vesteniusa, A.Wakedd, E.Yuberoar

In this study, the performance of two types of source apportionment models was evaluated by assessing the results provided by 40 different groups in the framework of an intercomparison organised by FAIRMODE WG3 (Forum for air quality modelling in Europe, Working Group 3). The evaluation was based on two performance indicators: z-scores and the root mean square error weighted by the reference uncertainty (RMSEu), with pre-established acceptability criteria. By involving models based on completely different and independent input data, such as receptor models (RMs) and chemical transport models (CTMs), the intercomparison provided a unique opportunity for their cross-validation. In addition, comparing the CTM chemical profiles with those measured directly at the source contributed to corroborate the consistency of the tested model results. The most commonly used RM was the US EPA- PMF version 5. RMs showed very good performance for the overall dataset (91% of z-scores accepted) while more difficulties were observed with the source contribution time series (72% of RMSEu accepted). Industrial activities proved to be the most difficult sources to be quantified by RMs, with high variability in the estimated contributions. In the CTMs, the sum of computed source contributions was lower than the measured gravimetric PM10 mass concentrations. The performance tests pointed out the differences between the two CTM approaches used for source apportionment in this study: brute force (or emission reduction impact) and tagged species methods. The sources meeting the z-score and RMSEu acceptability criteria tests were 50% and 86%, respectively. The CTM source contributions to PM10 were in the majority of cases lower than the RM averages for the corresponding source. The CTMs and RMs source contributions for the overall dataset were more comparable (83% of the z-scores accepted) than their time series (successful RMSEu in the range 25% – 34%). The comparability between CTMs and RMs varied depending on the source: traffic/exhaust and industry were the source categories with the best results in the RMSEu tests while the most critical ones were soil dust and road dust. The differences between RMs and CTMs source reconstructions confirmed the importance of cross validating the results of these two families of models.

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Piotr Manczarski, Krystyna Lelicińska-Serafin, Anna Rolewicz-Kalińska

The objective of the study is research on a biofilter existing at a mechanical-biological waste treatment plant in Radom. The paper presents results of research on the filling of the analysed biofilter (moisture, organic matter content, nutrient content, pH, grain size composition, and equivalent diameter), process gases (temperature, humidity and pH, concentrations of the main pollutants – ammonia, hydrogen sulphide, volatile organic compounds, acetic acid, ethanol) and operational parameters (flow rate, height of the biofilter layer, surface load, gas residence time in the filter bed). Irregularities were observed related to biofiltration efficiency, particularly resulting from improperly selected filling material and improper biofilter operation. The technological research permitted the identification of problems and determination of the requirement of performing necessary operational changes. Further works will involve the design, manufacture, and installation of an integrated biofilter with two-stage gas purification process (a classic biofilter and a semi-permeable membrane).

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Jarosław Chudzicki, Katarzyna Umiejewska

Since the 1990s, there have been trends in Central and Eastern European countries to reduce water consumption. This phenomenon is closely related to the political, social and economic changes in these countries and the introduction of economic instruments in water management. The article presents the changes in water consumption in households in the years 1950–2019 depending on the degree of equipping buildings with sanitary facilities, and the structure of water consumption for particular purposes. For the same period, the quality of sewage generated in households is presented on the basis of bibliography. The content of total suspended solids was the main analysed parameter. The last part of the article presents the quality of wastewater discharged to fourteen Polish wastewater treatment plants. The majority of the analysed plants show an increase in the concentration of total suspended solids in the domestic sewage discharged to them. This phenomenon may be influenced by the decreasing water consumption in households.

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Ewa Duda, Krzysztof Dziurzyński

Nowadays, the digital competence is becoming as important as literacy and numeracy skills. For children and youths these competences seem to be natural and the role of teacher is to direct students in their learning and to develop cognitive curiosity. For adults, the learning process is different. It is not only developing of digital skills but sometimes even grassroots teaching. The article presents a two different approaches to teaching/learning process provided in the field of secondary education – Finnish and Polish systems. Documents containing curricula, school programmes and course grids were analysed. Both systems have been assessed in terms of their relevance to adult learners. The main discoveries and the key conclusions indicate that the Polish system does not adapt to the real needs of adult learners and the changing needs of the labour market.

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Marta Wiśniewska

Waste management is an important element of sustainable urban development. One of the directions of waste management is mechanical-biological treatment (MBT) of waste with biogas installation. In addition to the benefits of purifying waste from separate collection and sorting of raw material waste from the mixed waste stream (subsequently diverted to recovery or recycling), this direction is also characterised by energy benefits (energy production from biogas). Mechanical and biological treatment of municipal waste inevitably entails also negative impacts, such as odour emission. In Poland, there are no legal regulations concerning odour nuisances. Reference could be made, inter alia, to BAT conclusions on waste treatment or standards in other countries. There are many methods of testing for odour emissions, but none of them, taken individually, characterises it sufficiently. The paper presents the results of research carried out in one of the biogas plants in Poland. The results present the sources of the highest odour emission in the examined plant, to which they belong: digestate during the second-stage oxygen stabilisation in the open air and pump station of technological sludge.

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Ferdinand Uilhoorn, Maciej Witek

Structural integrity and risk management have a wide interest because of its practical applications, such as oil and gas pipelines, piping systems under pressure in power stations, urban water, and heating networks. The main goal of this paper is twofold. Firstly, to estimate the unsteady pressureflow variations in a gas transmission grid within the framework of sequential data assimilation. This technique enables to determine accurately the maximum pressure at the localized defect on the pipeline by merging measurements that contain random errors into the inexact numerical flow model. For this purpose, a particle filter is used. The semi-discretization approach is applied to convert the nonisothermal flow model into an initial value problem of ordinary differential equations. The spatial discretization is based on a five-point, fourth-order finite difference approximation and the time marching was done using a diagonally implicit Runge-Kutta scheme. Secondly, to study the strength of steel tubes reinforced with composite sleeves containing localized part-wall thickness losses caused by corrosion while taking into consideration a safe operating pressure. For a steel thin-walled cylinder containing a wrap of fiberglass with epoxy resin, the burst pressure and sleeve thickness are determined. Finally, the repaired pipeline with a fiber-reinforced composite sleeve is investigated. The results enable operators to handle problems of corroded steel pipelines and develop effective repair activities during operation. For this reason, current research is important for the maintenance of underground steel networks.

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Janusz Kubrak, Elżbieta Kubrak, Edmund Kaca, Adam Kiczko, Michał Kubrak

This article introduces a flow controller for an upstream water head designed for pipe culverts used in drainage ditches or wells. The regulator is applicable to water flow rates in the range of Qmin < Q < Qmax and the water depth H0, exceeding which causes the gate to open. Qmin flow denotes the minimum flow rate that allows water to accumulate upstream of the controller. Above the maximum flow rate Qmax, the gate remains in the open position. In the present study, the position of the regulator’s gate axis was related to the water depth H0 in front of the device. Derived dependencies were verified in hydraulic experiments. The results confirmed the regulator’s usefulness for controlling the water level.

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Andrzej Kulig, Mirosław Szyłak-Szydłowski

Methodological aspects of odor studies in ex-post analyses for Polish wastewater management facilities were analyzed based on the example of a modernized and enlarged wastewater treatment plant (WWTP) in Mazovia, in the vicinity of the Warsaw agglomeration. It is a mechanical–biological treatment plant with increased efficiency of biogen removal, using activated sludge in the treatment process, with a maximum hydraulic capacity of 60,000 m3/day. Olfactometric research was carried out by means of a method based on identification and characterization of the odor plume emitted from the examined source. This paper presents the results of odor intensity assessment (in sensory examinations according to a 6-stage scale) and odor concentration measurement (using portable field olfactometers) after the completion of the project, and compares them with similar studies conducted before the commencement of the investment. A total of 10 measurement series were carried out before modernization, and 12 after modernization of the WWTP. Odor concentration and intensity were determined, and the current meteorological situation was assessed at the measurement and observation points (receptors) located within the premises (in total 462 points) and around the WWTP (342 points). In each series of measurements on the windward side of the treatment plant, the background of air pollution with odorous substances was marked. The research showed that air flowing into the area of the sewage treatment plant is clean in terms of odor. During the research, basic sources of odor nuisance were identified, and their impact before and after modernization was characterized. The results presented in radar diagrams show changes in the percentage distribution of frequency of occurrence of individual intensity values at receptor points within and outside the area of the treatment plant. After modernization, a significant decrease in the concentration of odor emitted from the sludge dewatering building and sludge containers was determined. The air-tightness of the sewage channel (covered with concrete slabs and sealed) resulted in a significant decrease in the concentration of odor emitted from this source. Waste (in particular, sewage sludge) collected in the emergency waste storage yard was identified as the main source of odor nuisance. The waste, even after modernization, was an emitter of odorous compounds spreading outside the area of the WWTP. Nevertheless, as a result of the investment, the desired effect of reduction of the degree of odor nuisance was achieved.

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Tadeusz Magiera, Adam Łukasik, Jarosław Zawadzki, Wolfgang Rösler

Forest topsoil is subjected to physical and chemical degradation due to the deposition of urban and industrial dust and landfill, as well as physical disturbances including a relic of former cultivation, clearcutting, and afforestation. Such disturbances are observed in all natural and semi-natural forests across Europe, but most intensively in urban forests surrounding cities and industrial areas. Magnetic susceptibility constitutes a convenient physical parameter that is used for both, determination of levels of industrial and urban dust deposition alongside relevant potentially toxic elements (PTEs), and for the precise localization of polluted areas (so-called “hot spots”). Deposited on the soil surface, technogenic magnetic particles (TMPs) contained in different kinds of anthropogenic dusts increase the magnetic susceptibility of polluted topsoil. This effect can easily be measured “in situ” by applying a geophysical (geomagnetic) technique – soil magnetometry – for which magnetic susceptibility is the basic parameter. This technique can be performed inexpensively and rapidly with high spatial resolution at local (e.g., for individual trees, and forest stand areas around pollution sources) and regional (for whole regions or countries) scales. The application of combined magnetic-chemical analyses together with geostatistical methods (especially cokriging methods) can deliver more significant results regarding the spatial distribution of pollution than chemical testing alone. A high degree of correlation between magnetic susceptibility and PTEs content (expressed in the form of Pollution Load Index) significantly improves the level of precision in localizing polluted areas. Knowledge of forest topsoil quality and the use of magnetic susceptibility for the precise delineation of areas with considerable anthropogenic physical and chemical disturbances may facilitate the management application of the ecosystem service concept at local and regional scales.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafn

Biogas plants processing municipal waste on the one hand represent a trend in waste management, and on the other hand constitute an alternative energy source. Next to their unquestionable benefits, due to the character of the provided activity, they can be a potential source of odours. Municipal waste, largely containing biodegradable fractions, is often subject to decomposition processes in uncontrolled conditions still before it is supplied to the mechanical biological treatment plant. One of the effects of the processes, both controlled and uncontrolled conditions, is emission of odorants. Their spread depends on the applied technologies and adherence to the technological regime during operation. One of the factors determining the types and concentrations of emitted odorants are also meteorological conditions in which waste is stored and processed. The paper presents results of two series of pilot research conducted at four plants, involving a preliminary analysis of the effect of meteorological conditions on the emission of odorants at biogas plants processing municipal waste.

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Wojciech Dąbrowski, Beata Karolinczak

In Poland, as well as across the whole world, an increase in craft beer production can be observed. In the last several years more than 150 of such breweries have appeared and according to Polish Brewery Association their number might ultimately reach 500. Many of them emerge in areas with no access to a central sewerage system so they have to solve the problem of waste management on their own. The article presents the results of research on the possibility of using a hybrid system for biological treatment of sewage from craft breweries. The sewage came from a craft brewery Waszczukowe located in Podlaskie province. A laboratory scale model consisted of a trickling filter (TF) (research model Gunt CE701e) and vertical flow constructed wetland (SS-VF). Innovative filling (Certyd produced by LSA company) of TF and SS VF was applied. The conducted study included determining changes in sewage parameters during hybrid treatment, as well as TF and SS VF efficiency separately. The aim of the research was to show the possibility of treating sewage to a point when it was possible to discharge it to a receiver, in compliance with Polish legal regulations. The research results might be used in designing a treatment system or sewage pretreatment in craft breweries. The average efficiency of TF operating with 100% recirculation was 76% for BOD5, 80% for COD, 26% for TN and 34% for TP while the total treatment efficiency of a hybrid system (TF and SS-VF) was 98%, 98%, 72% and 77% respectively. The load of TF during operation with recirculation was on average 0.38 kg BOD5 m-2d-1, 0.57 kg COD m-2 d-1. The load of SS-VF was on average 0.09 kg BOD5 m-2 d-1 and 0.12 kg COD m-2d-1. The obtained results of hybrid treatment permitted to discharge the sewage to the receiver.

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Publikacje pracowników w Bazie Wiedzy PW

Małgorzata Kwestarz, Maciej Chaczykowski

The power systems in European Union operate under energy policies where the greenhouse gases reduction, the increase of the share of renewable energy sources (RES) and the improvements in energy efficiency are the main objectives. Polish energy sector is currently based on inefficient usage of coal and must be transformed according to the requirements of EU energy and climate policy. A policy framework for climate and energy in the period from 2020 to 2030 established the target of 27% of share of RES in energy consumption. With the continuing increase in the use of RES, it is likely that more and more generation will have to be curtailed to maintain the stability of the power system which was not originally designed to integrate renewable generation. In this context, the conversion of renewable electricity to heat in connection with its storage in district heating systems, known as Power-to-Heat (PtH) can be considered as a viable option in increasing the share of RES and facilitating the stability of the power system. In this paper an attempt is made to estimate the potential of PtH technology for Poland up to 2030, including the high RES share scenario for the energy mix development.

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Monika Żubrowska-Sudoł, Agnieszka Garlicka, Justyna Walczak, Katarzyna Sytek-Szmeichel, Aleksandra Mikołajczak, Michał Stępień, Piotr Krawczyk, Katarzyna Umiejewska, Marcin Wołowicz

This paper presents the results of the first stage of the project, aimed at the assessment of the applicability of the new apparatus for disintegration of excess waste activated sludge. It was documented that the analysed device allows for disintegration of sewage sludge with an efficiency comparable to that obtained in other devices dedicated for mechanical disintegration of sewage sludge described in the literature. The disintegration process at energy density in a range of 35–210 kJ/l resulted in the release from activated sludge flocs of 219–515 mg SCOD/l for 35 kJ/l to 2138–4884 mg SCOD/l for 210 kJ/l.

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Ryszard Zwierzchowski, Olgierd Niemyjski

The paper presents a simulation of heat losses of a distribution network with different technical structure and under different operating conditions for a District Heating and Cooling (DHC) system. The DHC system consists of a Combined Heat and Power (CHP) plant and a Distribution Network (DN) with chambers and heat and cold substations. The different operating conditions of the DHC systems result in the DNs having variable transportation losses. The result of the analysis was used to verify the models and calculation methods of the fluid flow and heat losses in the DN, when cold is generated using either absorption or adsorption chillers. Different technical structure of a DN means a system of connected underground and aboveground piping with different diameters. DNs in Poland are usually installed as an underground, traditionally insulated piping placed in the concrete ducts (large diameter main pipelines) or a pre-insulated piping placed directly in the ground. The total heat losses of the DN differ according to the individual systems and depend on the size of the DHC system, its heating loads and quality of insulation of the piping. This paper presents the results of the numerical calculation of the temperature distribution in the soil around the piping channel using an FDA model. These results were utilized for numerical simulation of the water and heat flow through the DN and calculation of heat transportation losses. The numerical simulation of heat losses was performed for the particular system of connected underground and aboveground piping with different diameters. Finally, the heat transportation losses of the DN were calculated and compared for analyzed District Heating (DH) system i.e. without cold consumers and for the DHC system, when cold for consumers is generated using either the absorption or the adsorption chillers.

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Ryszard Zwierzchowski, Michal Pachocki

Increasing the energy efficiency of industrial installations is one of the European Union’s priorities for achieving energy policy goals. These goals can be achieved, among others, by applying the appropriate methodology for modernization of cooling water distribution pipelines and improving their operation. Water distribution in cooling systems of large industrial installations is associated with significant hydraulic losses due to large flows and spatial spread of these systems. The losses are unavoidable and have a decisive impact on the energy consumption for pumping. Thanks to optimal design solutions, implementation of the repair program and proper operation of cooling water transmission pipelines, it is possible to significantly reduce hydraulic losses and water leakage. This will translate into reduced energy consumption for pumping and, as a result, improved energy efficiency. Abovementioned goals can be achieved by replacing or renovating pipelines. This paper deals with determination of a method and schedule of modernization of cooling water piping systems on the basis of a case study – a large industrial plant. Firstly, evaluation of the existing condition is carried out. Data on flow rate and cooling water pressure in the system are collected and analyzed. A graphical and numerical database of the cooling water system is made, which maps the system in terms of system geometry (lengths, pipe diameters, ordinates) and flow and pressure streams. The hydraulic losses of the cooling water system are simulated. The results of simulation calculations of pressure losses in water distribution system are presented in the form of maps of water pressure distribution in pipelines. Calculations for the pipeline network are performed in the current state for two hydraulic load cases: maximum and average. An assessment of the failure rate is made on the basis of information about the place, time, cause and type of damage. Wall thickness of pipelines in selected locations is measured and samples are taken from pipes in places of failure. The reasons for water pipeline failures are diagnosed. On the basis of pre-modernization simulation, information on failure rate and forecasts of future water demand are obtained, it is proposed which pipeline sections and in what order should be modernized. Depending on the technical condition, pipeline diameter and location in the field, pipe replacement or renovation is recommended. For pipes to be replaced, new diameters, adjusted to the forecasted demand are calculated. For pipes qualified for renovation, different site hardened liners or full wall pipes are recommended depending on pipe condition. Renovation methods, despite the reduction of the internal cross-section, provide similar or lower hydraulic resistance values. After selecting the variants of modernization of distribution pipelines, hydraulic simulations are carried out in the post-modernization condition, taking into account the future demand for cooling water. The presented method can be applied to cooling water systems as well as other industrial water piping systems.

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Ryszard Zwierzchowski, Marcin Malicki, Maciej Lipka

The paper introduces an innovative conceptual model of a trigeneration system based on implementation of sorption devices in cascade configuration: absorption heat pumps and adsorption chillers connected with thermal energy storage, for recovering useless heat from secondary cooling circuit of a research nuclear reactor. Proposed trigeneration source provides building with useful heat for the purposes of heating system with thermal energy storage and cold for air-conditioning purposes. Also, desalinated water covering technological demand is produced. Useful heat is produced by an absorption heat pump, cold and desalinated water by adsorption chiller/desalinator. For the described trigeneration system calculations based on commercially available equipment (lithium-bromate absorption heat pumps and silica-gel adsorption chillers with desalination option) and required heat/cold/desalinate demand have been carried out. Operational data collected from an existing installation extended by introducing thermal energy storage to the system was used to simulate the heat demand during the year. 5-year operational data from the “MARIA” research nuclear reactor located at the National Center for Nuclear Research in Świerk, Poland was used to simulate low source variations for the absorption heat pump operation. The results of model implementation demonstrate a series of promising effects on many levels of system operation, including production of desalinated water on a large scale and significant reduction of: (I) energy usage (by 40% when considering only heating scenario), (II) nuclear fuel consumption, (III) heat delivery losses.

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Ryszard Zwierzchowski

The paper contains a method for improvement of operation of steam cushion system including its energy savings analyses, for a Thermal Energy Storage (TES) tank. Energy savings analyses were performed using operational data from selected Combined Heat and Power plants, which supply heat to large cities in Poland and are furnished with the TES. The role of the steam cushion system in the TES tank is to prevent the stored water against absorbing oxygen from atmospheric air. In the TES tank, which is a non-pressure tank, oxygen from atmospheric air could penetrate to the network water through the surge chamber and safety valves. The steam pressure under the roof is generated from technological steam injected under the roof. Energy savings in the steam cushion system are generated by using an appropriate technical solution for the upper orifice and suction pipe for circulation water, i.e., to make it movable through the use of pontoons. An isolating buffer layer is created at the top of the tank with very small convective and turbulent heat transport, which causes limited heat transfer from steam bed to the stored water in the tank. This results in heat flux of approximately 10% of the heat flux that occurs in the typical technical solution of the upper orifice and suction pipe for circulation water in the TES tank. This technology offers great opportunities to improve the operating conditions of District Heating System, cutting energy production costs and emissions of pollutants to the atmosphere.

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Katarzyna Umiejewska

Wastewater from breweries usually contains high levels of organic components, which are generally easily biodegradable. Ideally, the mainstream method of brewery wastewater treatment is based on biological transformation, which have been reported to be effective in efficiently reducing COD concentration. Anaerobic digestion technology plays an important role in the treatment of high strength wastewater [1]. The benefit of the process is biogas production and recovering the energy. The main goal of the paper is to present the results of a full-scale research performed in a brewery WWTP in 2016. Wastewater from brewery containing COD, a priority pollutant of organic components, is treated in IC reactor. The biogas produced during the anaerobic digestion is transformed into heat. Total COD and soluble COD were measured 5 days a week in wastewater before and after anaerobic reactor. In raw wastewater, average total COD was 5226 mg/L with the percentage share of soluble COD 89.4%. As a result of anaerobic treatment 83,7% reduction of total COD and 92.9% reduction of soluble COD were obtained. The average daily biogas production was 4089 m3/d.

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Piotr Fabijańczyk, Jarosław Zawadzki

This paper presents a new approach to the assessment of the uncertainty of using geostatistical Gaussian simulation in soil magnetometry. In the study area, numerous measurements of soil magnetic susceptibility were made, and spatial distributions of soil magnetic susceptibility were simulated. The parameters of variograms of soil magnetic susceptibility measured in the study area were determined and compared with those of simulated soil magnetic susceptibility. Regardless of the measurement scheme used, reproducibility of the original semivariograms of soil magnetic susceptibility was satisfactorily achieved when applying simulated values. A nugget effect, a sill, and a range of correlations of variograms of simulated values of soil magnetic susceptibility were similar to those of measured values. When the input data for the geostatistical simulation were averaged, the measured values of soil magnetic susceptibility and simulated spatial distributions were characterized by slightly lower standard deviations in comparison with the result of simulations based on the non-averaged, measured ones. At the same time, however, local variability of soil magnetic susceptibility was reproduced less. The accuracy of the calculations of point parameters and spatial distributions—based on the averaged values of soil magnetic susceptibility—were satisfactory, but when using geostatistical methods, it is recommended to use non-averaged magnetic susceptibility measurements.

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E. Pisoni, C. Guerreiro, S. Lopez-Aparicio, M. Guevara, L. Tarrason, S. Janssen, P. Thunis, F. Pfäfflin, A. Piersanti, G. Briganti, A. Cappelletti, I. D’Elia, M. Mircea, M.G. Villani, L. Vitali, L. Matavž, M. Rus, R. Žabkar, M. Kauhaniemi, A. Karppinen, A. Kousa, O. Väkevä, K. Eneroth, M. Stortini, K. Delaney, J. Strużewska, P. Durka, J.W .Kaminski, S. Krmpotic, S. Vidic, M. Belavic, D. Brzoja, V. Milic, V.D. Assimakopoulos, K.M. Fameli, T. Polimerova, E. Stoyneva, Y. Hristova, E. Sokolovski, C. Cuvelier

This paper presents the first outcomes of the “FAIRMODE pilot” activity, aiming at improving the way in which air quality models are used in the frame of the European “Air Quality Directive”. Member States may use modelling, combined with measurements, to “assess” current levels of air quality and estimate future air quality under different scenarios. In case of current and potential exceedances of the Directive limit values, it is also requested that they “plan” and implement emission reductions measures to avoid future exceedances. In both “assessment” and “planning”, air quality models can and should be used; but to do so, the used modelling chain has to be fit-for-purpose and properly checked and verified. FAIRMODE has developed in the recent years a suite of methodologies and tools to check if emission inventories, model performance, source apportionment techniques and planning activities are fit-for-purpose. Within the “FAIRMODE pilot”, these tools are used and tested by regional/local authorities, with the two-fold objective of improving management practices at regional/local scale, and providing valuable feedback to the FAIRMODE community. Results and lessons learnt from this activity are presented in this paper, as a showcase that can potentially benefit other authorities in charge of air quality assessment and planning.

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Marta Wiśniewska, Krystyna Lelicińska-Serafn

The paper presents examples of installations for the mechanical and biological treatment of municipal waste in Poland. Each of the presented installations is defined as a regional municipal waste treatment installation (RIPOK). Their technological solutions and work efficiency have been compared in this study. In addition, the loss of waste mass as a result of processes occurring in the biological part of individual installations was calculated in the research. The paper refers to the National Waste Management Plan (KPGO 2022) regarding the circular economy. As intended by the circular economy, MBP installations will be transformed into installations that will treat selectively collected municipal waste and become Regional Recycling Centers (RCR).

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Krystyna Lelicińska-Serafin, Anna Rolewicz-Kalińska, Piotr Manczarski

This study aimed to assess the efficiency of removal of volatile organic compounds (VOCs) from process gases from a food industry plant in East Poland, producing high-quality animal (goose, duck, and pig) and vegetable fats, using a two-stage method which is a combination of biological purification and membrane-separation. The research, conducted on the semi-technical scale, compared the effects of traditional and two-stage biofiltration carried out under the same process conditions. The concentrations of VOCs in process gases were measured by means of a multi-gas detector. Additionally the temperature and humidity of gases were determined by a thermoanemometer under filter bed, following the EU and Polish National Standard Methods Two different types of filling materials (the mix of stumpwood chips and bark, and the mix of stumpwood chips, bark, and compost) and two types of membranes (three-layer semi-permeable membrane fabrics were used, with differences in air permeability and water tightness) were analyzed. During all processes basic operational parameters, the biofilters were controlled, including surface load, volumetric load, duration of gas contact with the filling layer, flow rate, and pressure drops (in the biofilter and on the membrane). The analyzed gases were characterized by very high variability of VOC concentrations (ranging from 350 ppb to 11,170 ppb). The effectiveness of VOC removal (REvoc) was calculated by comparing the analytical results of raw and purified gases. The effectiveness of VOC removal with the application of traditional biofiltration during the experiment varied between 82% to 97% and was related to different parameters of the filling materials (mainly specific surface and moisture), reaching lower value for the mix of stumpwood chips and bark filling. The obtained results showed that the application of membrane improved the efficiency of biofiltration in all the analysed cases from 7% to 9%. The highest effectiveness was obtained using the filter bed in the form of stumpwood chips, bark, and compost in connection with the more permeable membrane. It was maintained between 96% to 99%, reaching an average value of 98%. The selection of the membrane should be determined by its permeability and the values of flow resistance.

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Magdalena Juszczak, Mirosław Szyłak-Szydłowski

The paper presents the results of the spread of the tetrahydrothiophene (THT) – used as odourant – in the gas network. Such analyses allow quick detection of leaks in networks, systems and devices of gas supply directly to consumers. The main goal of the study was to determine the effectiveness of the use of portable chromatograph and comparing it with a stationary odourant concentration analyser. Based on these studies, an attempt to determine the odouration zone for the selected city have been also taken. For this purpose, three series of measurements were made – in each series 13 points were analysed. Obtained results confirmed the effectiveness of the measurement a concentration of odourant in the gas network using a portable gas chromatograph – difference in relation to the stationary chromatograph ranged from 1.91 to 2.55 %.

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Agnieszka Malesińska, Mariusz Rogulski, Pierfabrizio Puntorieri, Giuseppe Barbaro, Beata Kowalska

Pipe lines are useful for transporting water for drinking, irrigation and for fireing over long distances, this pipe lines are called “Transmission line” and are used to carry conveying raw or treated water from a well field or remote storage (large lake, reservoir, etc.,) facility to a treatment plant and/or distribution storage tank. In water-carrying piping systems, dangerous phenomena may occur. One such phenomenon is water hammer.

The water hammer has always been an area of study, which has captivated the minds of researchers due to its complex and challenging phenomena. Modeling the phenomenon in real conditions is extremely difficult. Due to the dimensions of the piping systems, conducting research at real scales is impossible. However, thanks to the development of numerical methods, the study of water hammer and its effects can be performed using simulation programs. Unfortunately, the simulation results are not always consistent with the actual course of the phenomenon.

One of the parameters that describes the nature of the course of a water hammer is the velocity of propagation of the pressure wave, c, which is called celerity. The transient surge pressure, p, may be calculated from the pressure celerity c, and the sudden change in fluid flow velocity, ∆ v. In a piping system, the value of the pressure wave celerity is not equal to the individual celerity, c, for a single pipeline. Therefore for piping systems for ∆p calculations the equivalent celerity shell be used.

This article presents value of the equivalent celerity calculated from equations derived using linear analysis of natural vibrations of the system. For implement of the equations, an algorithm in MATLAB has been developed that allows one to easily calculate the equivalent celerity, ce, for N pipelines connected in series with varying diameter, length and material composition.

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Michał Sobieraj, Marian Rosiński

A high phase-separation efficiency auto-cascade refrigeration (ACR) system working with a zeotropic mixture of CO2 is proposed in this study. The selection of a high boiling-point component is analysed. A novel zeotropic mixture consisting of a high CO2 (R744) mass fraction together with isobutane (R600a) as a carrier fluid is proposed. An experimental setup was designed, built, and verified to study the ability of the ACR to provide isothermal refrigeration at temperatures lower than the R744 triple-point temperature. The setup employs a recuperative heat exchanger (RHX) for the maximum phase-separation efficiency. The effect of the refrigerant mass charge on the ACR operation was examined. The temperature distribution across the internal heat exchangers (IHXs) was studied as well. The results revealed that the system was very sensitive to the refrigerant mass charge. With a low mass charge, the ACR did not operate correctly owing to the pinch points occurring between the hot and cold ends of the IHXs. High mass charge resulted in increased power consumption and a decreased coefficient of performance (COP). Moreover, tests were conducted to examine the ability of the ACR system, working with a binary mixture of R744/R600a, to provide isothermal refrigeration with different evaporator heat loads. The ACR system was compared in terms of the evaporation pressure and mass flow to a cascade system working with trifluoromethane (R23) in the low stage. The ACR system can be a promising alternative to cascade systems working with R23. The mixture of R744/R600a presented a significant decrease in the global warming potential (GWP) compared with R23. Near-isothermal evaporation was possible with this mixture over a range of vapour quality values. The application range of CO2 was extended to temperatures lower than the CO2 triple-point temperature, using isobutane as a solvent for dry ice. The enthalpy–mass fraction diagrams incorporating a solid fraction area were constructed for the graphical representation of the ACR system.

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Krzysztof Radzicki, Łukasz Rybiański, Paweł Popielski

The thermal method is nowadays the only one that allows precise location of leaks in a shorings of a planned deep excavation, still before this excavation is made. It also allows to determine the leak intensity. As a consequence, it enables precise and early repair work, especially sealing. It allows to prevent or significantly reduce the serious consequences and losses resulting from a leaky excavation shoring. The paper presents the first in Poland case of the thermal detection of leaks in the excavation shoring at a construction site. This method has proven very effective in solving this complicated problem. The leaks were many and occurred in the diaphragm wall as well as under its lower edge. The depth of their occurrence reached over forty meters. The substrate‘s geology was highly heterogeneous. The method produced accurate details about the locations and intensity of the leaks.

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Agnieszka Machowska, Zbigniew Kledyński, Iwona Wilińska, Barbara Pacewska

The results of a study on the early hydration process of pastes composed of ground granulated blast furnace
slag and fly ash from fluidized bed combustion of brown coal are presented here. The results of the tests concerning
setting time, hydration processes (spectroscopy, calorimetry and thermogravimetry) and mechanical strength confirm that the
hydration process occurs and solid microstructures and hydration products (hydrated calcium silicates and aluminosilicates,
sulphoaluminates and calcium hydroxide) are formed. The presence of calcium carbonate was confirmed. Increasing the
amount of fly ash in pastes intensifies the process of early hydration, thereby accelerating the initial setting time and
increasing the amount of water bound in hydration products. The early compressive strength is also improved. For example,
the specimen containing the highest amount of fly ash showed a decrease in the initial setting time by about 20% and an
increase in the 2-day compressive strength by 22%, compared to the specimen containing the lowest amount of fly ash.

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Wojciech Dąbrowski, Beata Karolinczak, Paweł Malinowski, Dariusz Boruszko

Reject water is a by-product of every municipal and agro-industrial wastewater treatment plant (WWTP) applying sewage sludge stabilization. It is usually returned without pre-treatment to the biological part of WWTP, having a negative impact on the nitrogen removal process. The current models of pollutants removal in constructed wetlands concern municipal and industrial wastewater, whereas there is no such model for reject water. In the presented study, the results of treatment of reject water from dairy WWTP in subsurface vertical flow (SS VF) and subsurface horizontal flow (SS HF) beds were presented. During a one-year research period, SS VF bed reached 50.7% efficiency of TN removal and 73.8% of NH4+-N, while SS HF bed effectiveness was at 41.4% and 62.0%, respectively. In the case of BOD5 (biochemical oxygen demand), COD (chemical oxygen demand), NH4+-N, and TN (total nitrogen), the P-k-C* model was applied. Multi-model nonlinear segmented regression analysis was performed. Final mathematical models with estimates of parameters determining the treatment effectiveness were obtained. Treatment efficiency increased up to the specific temperature, then it was constant. The results obtained in this work suggest that it may be possible to describe pollutant removal behavior using simplified models. In the case of TP (total phosphorus) removal, distribution tests along with a t-test were performed. All models predict better treatment efficiency in SS VF bed, except for TP.

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Marta Wiśniewska

The aim of this study was to analyse the work of the MultiRAEPro gas detector in terms of its application in monitoring odour emissions from biogas plants processing municipal waste constituting part of a mechanical–biological waste treatment plant. The obtained results provided the basis for formulating conclusions concerning the use of a gas detector in monitoring odour emissions from biogas plants processing municipal waste. The study results can be applied in practice in biogas plants processing municipal waste as well as in other municipal facilities.

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Piotr Fabijańczyk, Jarosław Zawadzki, Tadeusz Magiera

The paper presents systematic study concentrations of selected rare-earth elements, namely La and Ce in soils of highly industrialized regions using geochemical and magnetometric measurements as well as geostatistical methods. Soil magnetometry was used to determine if the concentrations of La and Ce in soil could be a result of anthropogenic pollution or natural soil properties. Results of analyses revealed that the highest concentrations of La and Ce were observed near a waste heap of the plant producing and processing batteries, and in the region of the Jizera Mountains, natural REE-rich minerals are very common. It was also found that the lowest concentrations of La and Ce in soil were observed in forested areas of where the dominant type of pollution sources was associated with the metallurgical industry. Distributions of magnetic susceptibility in soil profiles collected in areas with predominant industrial influence showed visible peak in topsoil, what confirmed anthropogenic origin of La and Ce in soil. In areas where large volumes of wastes were deposited in past, industrial activity, vertical distributions of soil magnetic susceptibility showed also secondary, strong peak in subsoil. Thus, the results reveal that magnetometric measurements in soil profile might be useful as supplementary method for analyzing of concentrations of rare-earth elements. Contrary, magnetometric measurements performed on the soil surface were poorly correlated with a concentration of La and Ce in soil, because they have weaker magnetic properties than typical fly ashes emitted by industry.

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Stability of slopes is a topical and substantial issue, affecting areas where there are natural slopes as well as man-made slopes in urban areas, e.g. railway and road embankments, deep excavations or dams [123]. In these all cases, there are a large number of factors influencing the final safety factor value. Furthermore, numerical evaluation of the slope equilibrium state requires accurate representation in a computational model of soil and water conditions, which are determined by the geological structure. This is particularly important in areas which have been tectonically active or subject to intensive geodynamic processes in their geological history [e.g4567]. This is due to the potential occurrence of peculiar geological features, such as soil layers with reduced strength parameters [e.g8], layering associated with strength anisotropy [e.g9] and the presence of fault or discontinuity zones in the soil or rock mass [e.g1011]. For this reason, numerical models often do not adequately replicate real geological conditions. As a consequence, the modelled equilibrium state may not accurately correspond to reality and the computational geometry of the mass movement slip surface may be incorrect.

Moreover, in numerical modelling there are various consequences deriving from the calculation method selected for slope stability analysis, as discussed in [1] and [12]. Appropriate definition of the slope numerical model is also important (including: right type, sufficient number and proper size of finite elements). These aspects of modelling were discussed by the authors in an earlier publication [13].

This paper presents universal multistep significance analyses of the impact of individual specific soil and water conditions of a theoretical slope on its stability, expressed in terms of safety factor (SF). An evaluation of this type should be conducted in each case where there is a complex geological structure, on the basis of a properly planned parametric analysis, taking into account different cases of selected geological features.

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Piotr Marcinowski1, Jan Bogacki1, Maciej Majewski, Jarosław Zawadzki, Sridhar Sivakumar

Pollution released into the environment as the result of the combustion of energy fuels is a significant global threat. For instance, wastewater in coal–fired power plants is often heavily polluted by organic compounds, heavy metals and boron. Therefore, there is an urgent need for efficient flue gases and wastewater treatment. However, to be industrially implemented, the treatment processes have to be simultaneously effective and inexpensive. This research systematically studied the efficiency of inexpensive coagulation processes using aluminum-based coagulants applied to flue gas desulfurization (FGD) wastewater treatment. Additionally, the differences in the efficiency of total organic carbon (TOC) and chemical oxygen demand (COD) removal between sedimentation and coagulation processes were systematically studied. It was found that coagulation with the appropriate dose of PAX19XL coagulant achieved a satisfactory effect with significant boron removal and almost complete heavy metals removal. The polyelectrolyte use did not improve coagulation effectiveness and did not accelerate sludgesedimentation and volume decreasing. The detailed statistical analyses did not confirm the positive, pronounced effect of coagulation compared to sedimentation, although there were observed exceptions that should be considered separately. The results obtained suggest that inexpensive aluminum-based coagulants may be effective in improving the efficiency of flue gas desulfurization wastewater treatment in coal–fired power plants.

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J. Sowa, J. Hendiger, M. Maziejuk, T. Sikora, Ł. Osuchowski, H. Kamińska

Plants are the planet’s source of oxygen and the sink that removes carbon dioxide produced by burning, respiration and decay of organisms. The studies performed in small chambers indicated that plants also reduce volatile organic compounds (VOC’s). All these phenomena result in a fact that potted plants have a potential to improve IAQ and to some extent to support ventilation. Trends to “go green” increase the growing interest in the introduction of a large number of plants to offices. One should remember that work in modern offices is often associated with a high level of stress. Ornamental plants give highly significant reductions in negative mood states – reductions in anger, anxiety, depression, confusion, fatigue and stress. Leaves provide also additional sound attenuation and cooling effect due to evaporation. The paper summarises the R&D project devoted to the development of the efficient, safe and competitive systems of biofiltration based on the properties of potted plants. The paper presents examples of laboratory tests and describes first experiences from applications in two pilot office buildings.

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Adam Muszyński, Piotr Marcinowski, Justyna Maksymiec, Klaudia Beskowska, Ewa Kalwarczyk, Jan Bogacki

Wastewater from a cosmetic factory, with an initial chemical oxygen demand (COD) of 1140 mg/L, was treated using a combined light/Fe0/H2O2 process followed by biological treatment. The light/Fe0/H2O2 process, with 1000/2280 mg/L Fe0/H2O2 doses and 120 min process time, resulted in 70% COD removal, to final COD of 341 mg/L. The chemically treated wastewater was successfully subjected to biological treatment in a sequencing batch reactor (SBR), with up to 20% volume fraction in the influent, without significant deterioration of COD, nitrogen and phosphorus removal, but with possible small negative effects on polyphosphate accumulating organisms (PAOs), nitrifiers and other bacteria present in the microbial community. The COD of the effluent was in the range of 14–28 mg/L, resulting in overall COD removal of up to 97.7%. Untreated cosmetic wastewater, subjected to biological treatment in SBR, caused crucial changes in the microbial community structure, leading to a significant decrease in the efficiency of organic carbon, nitrogen and phosphorus removal.

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Arkadiusz Weglarz, Pawel Gilewski

In the changing world, the construction sector undergoes significant changes. New innovative technologies must be introduced, so this sector meets the requirements of sustainable development. In this article, we provide a comprehensive overview of various aspects of methods and techniques that when applied help to achieve the ambitious goals in terms of sustainability. Those aspects are methods applied to the support the design process of buildings, innovative building materials, modern installation systems, building management systems, and systems for managing the process of building operation.

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Beata Karolinczak

The paper presents the methodology and results of cost-effectiveness analysis of selected methods of wastewater treatment: activated sludge and biofi lter. The analysis concerns small municipal wastewater treatment plants with capacity of 10 to 500 m3d-1 in Poland (~100 to 5000 PE). It is based on data on total investment outlays, annual operating costs and total average annual costs. It has been shown that, in the case of investment outlays, there are no statistically signifi cant differences between technologies. However, the annual operating costs and the total average annual cost of wastewater treatment are the lowest when applying the biofi lter technology. The models presented in the paper can be used for costs estimation at the initial stage of designing municipal wastewater treatment plants. The total average annual cost of wastewater treatment determines the charges for sewerage services. This charge, alongside technological and environmental factors, as well as local conditions, should be one of the criteria for choosing a method for wastewater treatment.

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Ryszard Zwierzchowski, Olgierd Niemyjski

This paper deals with different operating conditions of a District Heating and Cooling (DHC) System and its influence on heat transportation losses of a District Heating Network (DHN). The different operating conditions of the DHC System’s mean different flow rate and temperature of the network water flowing in the DHN. These different operating conditions of the DHC System result in the DHNs having variable transportation losses. The analyzed DHC System consists of the Heat Only Boilers (HOB) plant and the DHN with substations and chambers. The DHNs in Poland are usually installed as underground, traditionally insulated piping placed in concrete ducts (large diameter and main pipelines) or pre-insulated piping placed directly in the ground. The result of the analysis was used to verify calculation methods of fluid flow and heat transportation losses of the DHN, when cold for consumers is generated using either absorption or adsorption chillers. The total heat transportation losses of the DHN differ according to individual systems and depend on the size of the DHC System, its heating loads and quality of insulation of the piping. This paper presents the results of the numerical calculation of the temperature distribution in the soil around the piping channel using an FDA model. The results of the numerical simulation of water and heat flow through the DHN allow to determine the total heat transportation losses of the DHN for different operating conditions of the DHC System.

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Marian Kwietniewski, Katarzyna Miszta-Kruk, Kaja Niewitecka, Mirosław Sudoł, Krzysztof Gaska

The security of water delivery of the required quality by water supply networks is identified with the concept of reliability. Therefore, a method of reliability evaluation of water distribution of the required quality was developed. The method is based on the probabilistic character of secondary water contamination in the water supply network. Data for the method are taken from monitoring of the water distribution system. The method takes into consideration the number and locations of individual measurement points and the results of the tests of water quality indicators at these points. The sets of measurement points and water quality indicators constitute a matrix research (observation) field in the model. The proposed method was implemented to assess the reliability of a water distribution process with respect to water with the required microbiological quality indicators in a real distribution system.

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Marta Wiśniewska, Andrzej Kulig, Krystyna Lelicińska-Serafn

Anaerobic digestion of the organic fraction from municipal solid waste offers the possibility of producing alternative energy from the produced biogas. Currently, there are eight biogas plants in Poland, where municipal waste is the feedstock for the fermentation process, but in the future, it is likely that much more will be built. For this reason, it is very important to characterise the sources of odour emissions in the plants in order to prevent complaints from residents of the region. The paper presents results of preliminary research in the field of identification and characteristic of odour sources in two selected biogas plants processing municipal waste in Poland: Wólka Rokicka-WR and Stalowa Wola-SW. The basic sources of odour were identified in relation to the biological treatment process and the pre-treatment of waste. The odour intensity and the concentration of odour and leading impurities were analysed. Results of the research of various technological solutions carried out in biogas plants were compared. The majority of big concentrations of odour and odorants are related to the operation of the biological part of both plants. The study revealed a strong dependency between the applied operation procedures, technological regime and the obtained measurement results. The highest correspondence between the results was obtained in both tested installations in the case of odour intensity and odour concentration, and in the case of concentration of NH3 and VOC.

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Ferdinand Evert Uilhoorn

In this work, we introduce a multiobjective optimization approach that seeks the optimal process noise statistics in the extended Kalman filter (EKF). The bi‐objective Mesh Adaptive Direct Search (BMADS) algorithm was used to minimize a performance index based on state estimate errors. The EKF estimated the gas flow dynamics in a pipeline system. Simulations were conducted with outflow boundary conditions for the flow model that contain gradual changes and discontinuities. To ensure shock‐capturing properties, the model was approximated with a semidiscrete finite volume scheme using Roe’s SUPERBEE limiter. The knee point in the Pareto front was based on normal boundary intersection approach and selected to compute the flow estimates. Numerical experiments demonstrated that BMADS is suitable for tuning the EKF and, compared to the normalized weighted sum method and nondominated sorting genetic algorithm, it showed to be superior in terms of computation time and most effective in finding Pareto optimal solutions.

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M. Rogulski, A. Badyda

Air quality is a serious problem in modern cities due to the significant impact of air pollution on the health of the population, the global environment and economy. Recent studies point to the crucial role of information about pollution on micro level, which translates into direct exposure of people to air pollutions. To provide such information, it is necessary to create real-time systems with large spatio-temporal resolution, since such information cannot provide conventional measurement systems performing measurements according to the legislative regulations of particular countries. Current researches focus on the concept of a next-generation air pollution monitoring systems that use new measurement technologies and techniques for communicating and delivering data. These systems can be complementary to traditional air quality monitoring systems. The article presents current trends in the world in this area – the example of static, social and vehicle measurement systems. There are also shown Polish initiatives related to environmental quality monitoring.

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Paweł Marcinkowski, Adam Kiczko, Tomasz Okruszko

Multi-channel rivers support diverse and productive ecological communities, and their rareness in the developed world places a great importance on their conservation. The design of side channel restoration projects remains poorly informed by theory or empirical observations. One of the last examples of anastomosing rivers in Europe is a stretch of River Narew in Poland protected as a national park. Park Authorities face a problem of side channels extinction in last few decades and therefore a dedicated plan of protection measures (submerged weir construction, dredging and mowing of side channels) was established aimed at anastomosing system conservation. The objective of this study was an ex-ante assessment of the impact of proposed protection measures on discharge distribution, flow velocity and sediment transport potential in the anastomosing section of the river, using a hydraulic, one-dimensional model. Among the tested measures, more invasive dredging and damming were significantly more efficient than less invasive vegetation removal. Compared to other restoration projects of multi-channel rivers (Narew and Rhône cases), supported by extensive post-restoration monitoring, efficiency level was comparable reaching on maximum tenfold increase in discharge and fivefold increase in reach-averaged flow velocity in restored side channels. Post-conservation alterations of hydraulic properties in the anabranches resulted in a significant increase in sediment transport potential for measures changing channel geometry. Such change could potentially ensure the stability of restoration eliminating the main cause of channels extinction i.e. excessive sediment deposition.

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Jeremi Hubert Naumczyk, Małgorzata Anna Kucharska, Joanna Agnieszka Ładyńska, Dominik Wojewódka

This study on tannery wastewater treatment showed that indirect electrooxidation by chlorine generated at a Ti/SnO2/PdO2/RuO2 (SPR) anode led to full ammonia removal and a decrease in chemical oxygen demand (COD) up to 58.9%. Summarized current efficiency of ammonia removal and apparent current efficiency of COD removal was very high and (up to 127.2%). Individual compounds present in raw and electrochemically treated wastewater and in synthetic tannin solutions were identified by GC-MS method. Dibutyl phthalate was determined in all samples of raw and/or wastewaters treated by electrooxidation and also in tannin solutions. For the wastewater sample D, current density of 1.0 A/dm2 values of adsorbable organically bound halogens were: 15.7, 19.8 and 12.9 mg/L after 15, 30 and 46 min, respectively. Additionally, a cost evaluation of this process was established. At a current density of 1.5 A/dm2, the energy consumption was in range from 78.2 to 171 kWh/kg of N–NH4+.

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Marta Dudek, Kacper Świechowski, Piotr Manczarski, Jacek A. Koziel, Andrzej Białowiec

Biochar (BC) addition is a novel and promising method for biogas yield increase. Brewer’s spent grain (BSG) is an abundant organic waste with a large potential for biogas production. In this research, for the first time, we test the feasibility of increasing biogas yield and rate from BSG digestion by adding BC, which was produced from BSG via torrefaction (low-temperature pyrolysis). Furthermore, we explore the digestion of BSG with the presence BCs produced from BSG via torrefaction (low-temperature pyrolysis). The proposed approach creates two alternative waste-to-energy and waste-to-carbon type utilization pathways for BSG: (1) digestion of BSG waste to produce biogas and (2) torrefaction of BSG to produce BC used for digestion. Torrefaction extended the short utility lifetime of BSG waste turned into BC. BSG was digested in the presence of BC with BC to BSG + BC weight ratio from 0 to 50%. The study was conducted during 21 days under mesophilic conditions in n = 3 trials. The content of dry mass 17.6% in all variants was constant. The kinetics results for pure BSG (0% BC) were: reaction rate constant (k) 1.535 d−1, maximum production of biogas (B0) 92.3 dm3∙kg−1d.o.m. (d.o.m. = dry organic matter), and biogas production rate (r), 103.1 dm3∙kg−1d.o.m.∙d−1. his preliminary research showed that the highest (p < 0.05) r, 227 dm3∙kg−1d.o.m.∙d−1 was due to the 5% BC addition. This production rate was significantly higher (p < 0.05) compared with all other treatments (0, 1, 3, 8, 10, 20, 30, and 50% BC dose). Due to the high variability observed between replicates, no significant differences could be detected between all the assays amended with BC and the variant 0% BC. However, a significant decrease of B0 from 85.1 to 61.0 dm3∙kg−1d.o.m. in variants with the high biochar addition (20–50% BC) was observed in relation to 5% BC (122 dm3∙kg−1d.o.m.), suggesting that BC overdose inhibits biogas production from the BSG + BC mixture. The reaction rate constant (k) was not improved by BC, and the addition of 10% and 20% BC even decreased k relatively to the 0% variant. A significant decrease of k was also observed for the doses of 10%, 20%, and 30% when compared with the 5% BC (1.89 d−1) assays. 

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Jan Bogacki, Jarosław Zawadzki

Magnetic material may be added to proppant, as the magnetic marker allows to determine the range and efficiency of hydraulic fracturing. However, magnetic proppant may be also used in flowback fluid treatment and monitoring of environmental pollution. As a result of shale gas hydraulic fracturing, large volume of flowback fluid is created. Flow back fluid have similar properties to fracturing fluid, but it is potentially enriched with large amount of salts and organic compounds leached from shale. Magnetic proppant may serve as a heterogeneous catalyst during organic pollutants decomposition. Additionally, in case of leakage and consequently the fracturing fluid pollution, magnetic proppant is placed into the soil environment. It can be detected using magnetometric methods. This article discusses the above-mentioned issues based on the knowledge and experience of the authors and the literature review.

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Apoloniusz Kodura, Katarzyna Weinerowska-Bords, Wojciech Artichowicz, Michał Kubrak, Paweł Stefanek

This paper presents a numerical model of transient flow in a pressure slurry pipeline network with verification based on in situ measurements. The model, primarily verified in laboratory conditions, has been extended and applied to the case of a large and complex slurry pipeline network in Poland. In the model, the equivalent density concept was applied. In situ experiments were performed for various unsteady flow episodes, caused by different pump operation strategies in the industrial pipeline network. Based on the measurements of slurry concentration and pressure variations, the numerical model was tested and verified. A satisfactory coincidence between the calculated and the observed pressure characteristics was achieved. Additional numerical tests led to important conclusions concerning safe pump and valve operation and system security threats.

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Michał Sobieraj, Marian Rosiński

Carbon dioxide, a natural refrigerant, is attracting attention as a direct solution to the legal restrictions on hydrofluorocarbon (HFC) refrigerants. The use of carbon dioxide as a refrigerant is limited by the triple point temperature of −56.5 °C. However, used along with a carrier fluid, carbon dioxide can provide refrigeration to temperatures lower than the triple point. A blend composed of carbon dioxide (R744) and isobutane (R600a) is experimentally studied. An experimental setup was designed, built, and verified in order to obtain the sublimation heat transfer coefficients of R744/R600a mixtures at temperatures lower than −56.5 °C. The test section comprises a horizontal copper tube with an inner diameter of 10 mm and length of 1 m. The tube is electrically heated by a copper wire heater wrapped uniformly around the tube. The tests were conducted with a novel refrigerant blend at heat fluxes from 3630 W m−2 to 8480 W m−2. The heat transfer coefficient decreases with increasing heat flux. Furthermore, a heat transfer coefficient calculation correlation has been developed.

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Andrzej Białowiec, Karolina Sobieraj, Grzegorz Pilarski, Piotr Manczarski

There are insufficient data for the development of process design criteria for constructed wetlands systems based on submerged plants as a major treatment agent. The aim of the study was to evaluate the oxygen transfer capacity (OTC) of E. densa, in relation to wet plants’ mass (w.m.), and the influence of E. densa on the oxygen concentration and contaminants’ removal efficiency from municipal wastewater. The obtained oxygen concentration and temperature data allowed to calculate the OTC values (mg O2·L−1·h−1), which had been related to wet plants’ mass unit (mg O2·L−1·h−1·g w.m.−1). The efficiency of wastewater treatment was determined in relation to initial wastewater content in the mixture of wastewater and tap water (0%, 25%, 50%, and 100%) during 3 days of the experiment duration. The simulation of day and night conditions was done by artificial lighting. Before and after finishing the second experiment, the COD, Ntotal, and P-PO4 concentration were analyzed in wastewater solutions. The OTC ranged from 3.19 to 8.34 (mgO2·L−1·h−1·g w.m.−1), and the increase of OTC value was related to the increase of wet plant’s mass. The research showed that E. densa affected positively on the wastewater treatment efficiency, and the highest efficiency was achieved in 25% wastewater solution: 43.6% for COD, 52.9% for Ntotal, 14.9% for P-PO4.

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Aniela Glinicka, Szymon Imiełowski

In aggressive environments structural steel components
of engineering structures may become affected by
corrosion. Even with corrosion protection, their critical load
capacity and stability are seriously affected by the consequences
of corrosion in aggressive environments due to impurities and
possible failures. In this paper a critical state analysis of corroded
struts is presented. The input data for the analysis was taken from
laboratory corrosion tests in which steel pipes of a few different
diameters were subjected to the attack of sulphuric and
hydrochloric acids and placed in salt spray tester. The loss of
material due to corrosion was determined and graphs, presenting
the loss of material as a function of pipe diameter and the
corrosion rate over time, were determined. The relative decrease
of the maximum elastic strain energy which can be stored in the
strut and the relative decrease of the critical load of elastic
buckling were calculated for a series of corroded pipes. The
curves of the relative change of the maximum elastic strain energy
and the relative change of critical load over the time of corrosion
progression were found to follow a similar path. For determining
the critical load for a given strut, boundary conditions are taken
into consideration. However, it is not necessary in the case of
maximum elastic strain energy, which makes it a more convenient
stability measure of the critical load capacity of strut.

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Marta Chludzińska

The aim of this study was to find the most favourable shape of the front panel perforation shape, which would allow us to obtain the greatest cooling effect and – at the same time – be positively perceived by the people. The capacity of the personalized ventilation (PV) system to affect human thermal sensation, with different shapes of front panel perforation used, was analyzed.

Once the pilot study was conducted, it used a rectangular nozzle of front pattern size 320 mm × 125 mm and six different front patterns perforation shapes with round holes were tested. Operational parameters such as: airflow 20 l/s, supply air temperature at 24 °C or ambient temperature at 28 °C were invariable. The experiment consisted of a two-stage analysis of air jets characteristics and of tests in which people participated. Twenty-five male volunteers, at the age of 22–23 were engaged. They their assessed thermal sensation and completed relevant questionnaires.

On the basis of the results of the above study, differences in jet characteristics depending on the pattern shapes and their different impact on thermal sensation of the volunteers were demonstrated. The biggest cooling effect was obtained using front panels with small hole size (d = 5 mm). These perforations allowed us to obtain a more even air outflow from the entire panel. This ensured a broader airflow of lower velocity, reaching and affecting a larger area. With holes of larger size (d = 15 mm), air outflow occurred mainly through the central part, which produced narrow jets of higher velocity.

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Jacek Wąsowski, Dariusz Kowalski, Beata Kowalska, Marian Kwietniewski, Małgorzata Zawilska

This research focused on a model setup fed with underground water pumped into a water supply network. The scope of the research included a long- and a short-term stagnation of water in the setup and a water flow of 0.1 m/s. The water supplied into the system gradually lost its corrosive properties and developed calcium carbonate precipitation capability. These processes indicated that cement components migrate from the lining into the water. Apart from the primary components, the presence of the following trace elements was found: iron (399.6 ppb), magnesium (17.8 ppm), zinc (26.9 ppb), barium (22.6 ppb), boron (21.6 ppb), sodium (10.8 ppm), gallium (2.1 ppb). At early stages of the operation, recorded quantities were not significant. Leaching of the trace elements from cement increased after water was chlorinated. In turn, the highest percent increases were observed in the case of zinc (217%), boron (19%) and gallium (12%), whereas the increase for sodium, iron, barium and magnesium in water was insignificant (reaching a few percent). A repeated analysis of samples of stagnant water in the setup showed that most of trace elements were below the detectability level. Final concentrations of all elements identified in the water after its contact with internal cement mortar lining were much lower than the limit values set out for drinking water

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Sonam Wangchuk, Tobias Bolch, Jarosław Zawadzki

The majority of glacial lakes around the world are located in remote and hardly accessible regions. The use of remote sensing data is therefore of high importance to identify and assess their potential hazards. However, the persistence of cloud cover, particularly in high mountain areas such as the Himalayas, limits the temporal resolution of optical satellite data with which we can monitor potentially dangerous glacial lakes (PDGLs). The ability of Synthetic Aperture Radar (SAR) satellites to collect data, irrespective of weather and at day or night, facilitates monitoring of PDGLs by without compromising temporal resolution. In this study, we present a semi-automated approach, based on a radar signal intensity threshold between water and non-water feature classes followed by post-processing including elevations, slopes, vegetation and size thresholds, to delineate glacial lakes in Sentinel-1 SAR images in Bhutan Himalaya. We show the capability of our method to be used for delineating and monitoring glacial lakes in Bhutan Himalaya by comparing our results to 10 m resolution Sentinel-2 multispectral data, field survey data, meteorological data, and a time series of monthly images from January to December 2016 of two lakes. Sentinel-1 SAR data can, moreover, be used for detecting lake surface area changes and open water area variations, at temporal resolution of six days, providing substantial advantages over optical satellite data to continuously monitor PDGLs.

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Jakub Pulka, Piotr Manczarski, Jacek A. Koziel, Andrzej Białowiec

We propose a ‘Waste to Carbon’ thermal transformation of sewage sludge (SS) via torrefaction to a valuable product (fuel) with a high content of carbon. One important, technological aspect to develop this concept is the determination of activation energy needed for torrefaction. Thus, this research aimed to evaluate the kinetics of SS torrefaction and determine the effects of process temperature on fuel properties of torrefied products (biochars). Torrefaction was performed using high ash content SS at six (200~300 °C) temperatures and 60 min residence (process) time. Mass loss during torrefaction ranged from 10~20%. The resulting activation energy for SS torrefaction was ~12.007 kJ·mol−1. Initial (unprocessed) SS higher heating value (HHV) was 13.5 MJ·kg−1. However, the increase of torrefaction temperature decreased HHV from 13.4 to 3.8 MJ·kg−1. Elemental analysis showed a significant decrease of the H/C ratio that occurred during torrefaction, while the O/C ratio fluctuated with much smaller differences. Although the activation energy was significantly lower compared with lignocellulosic materials, low-temperature SS torrefaction technology could be explored for further SS stabilization and utilization (e.g., dewatering and hygienization).

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Andrzej Białowiec, Jacek A. Koziel, Piotr Manczarski

In this research, we explore for the first time the use of leaf stomatal conductance (gs) for phytotoxicity assessment. Plants respond to stress by regulating transpiration. Transpiration can be correlated with stomatal conductance when the water vapor pressure gradient for transpiration is constant. Thus, our working hypothesis was that the gs measurement could be a useful indicator of the effect of toxic compounds on plants. This lab-scale study aimed to test the measurement of gs as a phytotoxicity indicator. Our model plants were two common hydrophytes used in zero-effluent constructed wetlands for treating landfill leachate. The toxic influence of two types of leachate from old landfills (L1, L2) on common reed (Phragmites australis (Cav.) Trin. ex Steud.) and sweet flag (Acorus calamus L.) was tested. The gs measurements correlated well with plant response to treatments with six solutions (0 to 100%) of landfill leachate. Sweet flag showed higher tolerance to leachate solutions compared to common reed. The estimated lowest effective concentration (LOEC) causing the toxic effect values for these leachates were 3.94% of L1 and 5.76% of L2 in the case of reed, and 8.51% of L1 and 10.44% of L2 in the case of sweet flag. Leachate L1 was more toxic than L2. The leaf stomatal conductance measurement can be conducted in vivo and in the field. The proposed approach provides a useful parameter for indicating plant responses to the presence of toxic factors in the environment.

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Agnieszka Tabernacka, Ewa Zborowska, Katarzyna Pogoda, Marcin Żołądek

A one-step technological system containing activated sludge fed with synthetic domestic wastewater was applied to treat waste air polluted with tetrachloroethene (PCE). In the first stage of the experiment, air passed through a bioscrubber; in the second and third stages, it passed through the bioreactor containing activated sludge and bacteria immobilised in oak chips. These bacteria are active in PCE biodegradation. Process efficiency in the final stage of the experiment was high; the elimination capacity was 0.23 g m−3 h−1 with the PCE mass loading rate of 0.58 g m−3 h−1. It has been shown that in the activated sludge bioreactor, bacteria adapted to PCE biodegradation and the wood chips protected microorganisms from the toxic effects of pollution. The dominant strains of bacteria immobilised in wood chips have been identified. Most of them were Gram-negative rods – Pseudomonas aeruginosaPseudomonas putidaRalstonia pickettii and Ochrobactrum anthropii. Only one strain was Gram-positive and of cylindrical shape. The results of the study indicate the potential of immobilised bacteria capable of degrading chlorinated aliphatic hydrocarbons for the air and wastewater treatment. The low cost of the treatment process is an advantage.

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Grzegorz Kubicki, Izabela Tekielak-Skałka, Marcin Cisek

Purpose: The aim of the analysis was to investigate how smoke would spread in the building in the case of fire, and how to protect staircases without
a pressure differential system (PDS). It was assumed that a ventilation system should:
– prevent the staircase against complete smokiness. The part of the staircase located below the level covered by the fire should be smoke-free to the
extent allowing the evacuation of people from the fire compartments;
– remove smoke from the staircase as fast as possible to prevent a significant increase in the level of pressure in the staircase.
Project and methods: Research was conducted in a full-scale 9-storey building. Three real fires were simulated. Typical apartment furnishings were
used in the fires. A smoke ventilation system was installed in the staircase with variable make-up air supply. Tests were carried out for the following
configurations of smoke ventilation systems:
– natural smoke exhaust with natural/gravitational make-up air;
– natural smoke exhaust with a mechanical (fixed volume of 14000 m3/h) make-up air inlet;
– natural smoke exhaust with a variable mechanical make-up air inlet.
The position of the door between the staircase and the apartment was used as an additional variable.
The measurements included temperature, light transmittance in the staircase, pressure difference between the staircase and the external environment,
and the flow of the air and smoke through the smoke damper.
Results: The results of the research show that the system of gravitational smoke ventilation is susceptible to ambient conditions such as temperature.
In some tests, it was observed that smoke could descend below the storey covered by the fire. The conducted research helped determine the best way
to reduce the amount of smoke in the staircase. The use of mechanical air supply in the smoke ventilation system facilitated fast smoke removal from
the staircase, and the proper air and smoke flow direction (from the test room to smoke exhaust devices).
The use of mechanical make-up air supply in the smoke ventilation system prevented the smoke from descending below the storey covered by the fire, so
that the staircase on the floor covered by the fire could remain free from smoke in the lower part, providing a way of escape from the level covered by the fire.
Conclusions: The conducted tests have revealed that the best solution to protect staircases without PDSs is to use a smoke ventilation system comprising
a smoke vent mounted at the top and mechanically adjusted make-up air supply on the ground level.

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Anna Sosnowska

Riverbed under the influence of natural and anthropogenic factors is constantly being transformed. The changes of the channel parameters related to natural phenomena are rarely dynamic. Contrarily it is in the case of human activity. The introduction of river engineering structures to the riverbed aims to quickly adapt the river to the requirements. If construction of such forms is designed taking account of natural conditions prevailing in the riverbed, then negative effects cannot be observed. The situation is different when the river’s characteristics were not considered in the design process. The article discusses the changes that the riverbed has undergone due to its intensive contraction at the ferry crossing at km 488 of Vistula, in Gassy. Current and archival aerial photographs were analyzed in terms of the transformation of the riverbed width, as well as the size of the mid-channel islands. The focus was concentrated on a section of the river 2 km above and 4 km below the ferry crossing. In particular, the parameters of the channel bar located directly below the narrowing and their change over the last decades were analyzed. Conclusions were drawn regarding the case study and recommendations for designing analogous solutions ensuing from the analysis were formulated.

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Jan Bogacki, Piotr Marcinowski, Balkess El-Khozondar

One of the major environmental concerns associated with waste disposal is the large amount of generated landfill leachates (LL), which are considered a type of wastewater with a complex composition. There is an urgent need to find an effective LL treatment method. LL were subjected to pretreatment followed by the Fe0/H2O2 process. Pretreatment efficiency was coagulation at pH 6.0 >> coagulation at pH 9.0 > acidification at pH 3.0. Coagulation at pH 6.0 in an optimal Fe3+ dose of 1000 mg/L decreased total organic carbon (TOC) from the initial concentration of 1061 mg/L to 491 mg/L while acidification to pH 3.0 decreased TOC to 824 mg/L. After acidification, the Fe0/H2O2 process with 8000/9200 mg/L Fe0/H2O2 reagent doses decreased TOC to 499 mg/L after a processing time of 60 min. Performance of the Fe0/H2O2 process after coagulation at pH 6.0 for optimal Fe0/H2O2 8000/5540 mg/L reagent doses decreased TOC to 268 mg/L (75% TOC removal). Treatment of landfill leachates with combined process coagulation and Fe0/H2O2 also increased their susceptibility to biodegradation, expressed as the biochemical oxygen demand/chemical oxygen demand (BOD5/COD) ratio from 0.13 to 0.43, allowing LL to be considered as susceptible to biodegradation. Fe0/H2O2 process kinetics was described. A statistical analysis confirmed the obtained results. The proposed method can be successfully applied for LL treatment.

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Damian Zasina, Jarosław Zawadzki

Emission mapping distinctly facilitates observations and analysis of the anthropogenic CO2 emission impact, and the population data is frequently used for preparing spatial distributions of the CO2 emissions and also its precursors. Spatial analysis of the emissions or e.g. carbon footprint estimated for the spatially scattered sector such as residential combustion (IPCC sector 1A4bi) can be very hard to carry out, especially if in particular location considerable part of population is supplied with the heat from the district heating infrastructure. In this paper we propose the algorithm for spatial split between dwellings supplied from the district heating (CO2 emission in the sector 1A1a) and not supplied – emitting CO2 in the sector 1A4bi. Applying of the proposed algorithm changes distinctly the CO2 emission’s spatial distribution. The emissions are corrected only in grid cells which have non empty intersection with the district heating arteries. Validation of the model indicated 6% difference between the actual number of dwellers supplied from the heating system, and modelled. The authors suggest applicability of the algorithm for the CO2 emissions inventoried together with its precursors.

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A. Rozmysłowska-Wojciechowska, E. Karwowska, S. Poźniak, T. Wojciechowski, L. Chlubny, A. Olszyna, W. Ziemkowska, A. M. Jastrzębska

The number of investigations regarding the application of 2D nanosheets of MXenes in different technological areas is growing rapidly. Different surface modifications of MXenes have been introduced to date in order to tailor their properties. As a result, surface-modified MXenes could be released in the environment from filtration membranes, adsorbents, or photocatalysts. On the other hand, assessment of their environmental impact is practically unexplored. In the present study, we examined how modification of the antimicrobial Ti3C2 MXene with ceramic oxide and noble metal nanoparticles affects its toxic behavior. The expanded 2D sheets of the Ti3C2 MXene phase were modified with Al2O3/Ag, SiO2/Ag, and SiO2/Pd nanoparticles using the sol–gel method and extensively characterized. The obtained 2D nanocomposite structures were characterized by antibacterial properties. The ecotoxicological assays considered green algae (Desmodesmus quadricauda) as well as two higher plants: sorghum (Sorghum saccharatum) and charlock (Sinapis alba). Our results revealed that obtained nanomaterials can cause both stimulating and inhibiting effects towards algae, and the ecotoxicity depended on the concentration and the type of modification. The study reveals the intriguing property of pristine Ti3C2 which highly stimulated green algae growth at low concentrations. It also shows that modification of pristine Ti3C2 MXene with different nanoparticles changes the ecotoxicological effects of the resulting nanocomposite 2D structures. We have also indicated nanocomposite structures that does not revealed the toxic effect on tested organisms i.e. the Ti3C2 MXene surface-modified with Al2O3/Ag was not phyto- and eco-toxic. This work helps with better understanding of the reactivity of surface-modified MXenes towards chosen organisms, giving more information concerning the potential impact of tested nanocomposites on the ecosystems.

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Piotr O. Czechowski, Piotr Dąbrowiecki, Aneta Oniszczuk-Jastrząbek, Michalina Bielawska, Ernest Czermański, Tomasz Owczarek, Patrycja Rogula-Kopiec and Artur Badyda

This article marks the first attempt on Polish and European scale to identify the relationship between urban and industrial air pollution and the health conditions of urban populations, while also estimating the financial burden of incidence rates among urban populations for diseases selected in the course of this study as having a causal relation with such incidence. This paper presents the findings of a pilot study based on general regression models, intended to explore air pollutants with a statistically relevant impact on the incidence of selected diseases within the Agglomeration of Gdańsk in the years 2010–2018. In discussing the city’s industrial functions, the study takes into consideration the existence within its limits of a large port that services thousands of ships every year, contributing substantially to the volume of emissions (mainly NOx and PM) to the air. The causes considered include the impact of air pollution, seasonality, land- and sea-based emissions, as well as their mutual interactions. All of the factors and their interactions have a significant impact (p ≤ 0.05) on the incidence of selected diseases in the long term (9 years). The source data were obtained from the Polish National Health Fund (NFZ), the Agency for Regional Monitoring of Atmosphere in the Agglomeration of Gdańsk (ARMAAG), the Chief Inspectorate of Environmental Protection (GIOŚ), and the Port of Gdańsk Harbourmaster. The study used 60 variables representing the diseases, classified into 19 groups. The resulting findings were used to formulate a methodology for estimating the financial burden of the negative health effects of air pollution for the agglomeration, and will be utilized as a reference point for further research in selected regions of Poland.

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Agnieszka Maria Jastrzębska, Ewa Karwowska, Tomasz Wojciechowski, Wanda Ziemkowska, Anita Rozmysłowska, Leszek Chlubny, Andrzej Olszyna

The expanded Ti2C and Ti3C2 MXene phases were synthesized from their parent Ti2AlC and Ti3AlC2 MAX phases using the same conditions of the classical acidic aluminum extraction method. The assumption for the study was that the expanded Ti2C and Ti3C2 MXenes are composed of the same atoms and if are synthesized from MAX phases using the same conditions of the classical acidic aluminum extraction method, the observed bio-effects can be related only to the changes in their structures. The scanning electron microscope investigations indicated that the expanded Ti2C and Ti3C2 sheets formed the specific network of slit-shaped nano-pores. The x-ray photoelectron spectroscopy for chemical analysis (ESCA-XPS) showed almost no difference in surface chemistry of Ti2C and Ti3C2 MXenes. The high-resolution transmission electron microscope investigations revealed, however, differences in atomic structure of the individual Ti2C and Ti3C2 sheets. Measured distance between Ti-C atomic layers in Ti2C was 9.76 Å and was larger by 0.53 Å in comparison with Ti3C2 (9.23 Å). Our investigations of bioactive properties toward model gram-negative Escherichia coli bacterial strain showed that the Ti2C MXene did not influence the viability of bacteria. Contrarily, the Ti3C2 MXene showed antibacterial properties. The results of the study indicate that the structure at the atomic scale may play a key role in the bioactivity of MXenes of the same chemical composition, but different stoichiometry, just like in case of Ti2C and Ti3C2.

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Kwestarz Małgorzata, Osiadacz Andrzej J., Kotyński Łukasz

Leak detection in transmission pipelines is important for safe operation of pipelines. The probability of leaks may be occurred at any time and location, therefore pipeline leak detection systems play a key role in minimization of the occurrence of leaks probability and their impacts. During the operation of the network there are various accidents or intentional actions that lead to leaks of gas pipelines. For each network failure, a quick reaction is needed before it causes more damage. Methods that are used to detect such network failures are three-staged-: early identification of leakage, an accurate indication of itslocation and determine the amount of lost fluid. Methods for leak detection can be divided into two main groups: external methods (hardware) and internal methods (software). External leak detection methods require additional, often expensive equipment mounted on the network, or use systems that could display only local damage on the pipeline. The alternative are the internal methods which use available network measurements and signalling gas leakage signal based on the mathematical models of the gas flow. In this paper, a new method of leak detection based on a mathematical model of gas flow in a transient state has been proposed.

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Barbara Błaszczak, Kamila Widziewicz-Rzońca, Natalia Zioła, Krzysztof Klejnowski, Katarzyna Juda-Rezler

Air pollution by particulate matter (PM) is recognized as a one of the most important environmental issue. A particular attention is being paid to fine PM fraction (PM2.5, PM1.0) due to its detrimental impact on human health and long-term persistence in the air. Presented work is an in-depth bibliometric study on the concentrations and chemical composition of PM2.5 among 27 rural and 38 urban/urban background stations dispersed across the Europe. Obtained results indicate that the chemical composition of PM2.5, in terms of mass concentrations and percentage contribution of main chemical constituents, is relatively different in various parts of Europe. Urban and urban background stations are typically characterized by higher share of total carbon (TC) in PM2.5, compared to rural background sites, mostly pronounced during the heating periods. The share of the secondary inorganic aerosol (SIA) is typically higher at rural background stations, especially in North-Western Europe. In general, the relative contribution of SIA in PM2.5 mass, both at rural and urban background stations, showed more or less pronounced seasonal variation, opposite to Polish measurement sites. Moreover, Poland stands out from the majority of the European stations by strong dominance of total carbon over secondary inorganic aerosol.

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