Abstracts

2012 year


No. 59

 

„Contemporary Problems of Engineering and Protection of Environment”

TABLE OF CONTENTS:

Adam Masłoń, Janusz A. Tomaszek
Trend of use of powdered mineral materials in activated sludge technology – literature review. pp. 5
Keywords: biological wastewater treatment, activated sludge, powdered mineral materials.

SUMMARY

The paper presents literature review of use of powdered mineral materials in order to enhance biological wastewater treatment and aid activated sludge systems. The impact of powdered materials to upgrade the activated sludge process and to improve settling dynamics of activated sludge were demonstrated. The paper determined the mechanism and the improvement effect of activated sludge technology with powdered materials. According to type and chemical composition, powdered materials can act as a weight of activated sludge, sorbent and microcarrier for the biofilm. Zeolites, talc, chlorite, kaolin and bentonite are most often used in activated sludge technology.

Helena Chrzanowska, Jacek Piekarski, Mariusz Kozak
Preliminary studies on the use of ion-selective probes for control of nitrogen removal process from sewage at a municipal Sewage Treatment Plant Jamno in Koszalin. pp. 25
Keywords: Automation of sewage treatment plants, ion-selective probes, removal of nitrogen.

SUMMARY

Properly selected and installed control and measurement equipment facilitates running processes of nitrification and denitrification in a correct and economical way. Measuring devices should be simple; they should not require a large involvement of the staff and should be cheap during operation. That is why the paper presents research carried out on an industrial scale at Sewage Treatment Plant Jamno in Koszalin. It consists of determination of suitability of the application of a compound meter for automatic control of nitrogen removal processes from sewage, based on ion-selective probes for measuring the concentration of ammonium and nitrate ions.

Jacek Piekarski
Analysis of resistance of fluids flow through a porous layer – model investigations. pp. 39
Keywords: gravitational filtration, compressibility of deposit, model investigations.

SUMMARY

Under the influence of various factors, the thickness of porous layer in the process of gravitational filtration is reduced by a small extent, which causes decrease of porosity, and thus values of filtration and permeability coefficients, and the appreciation of the general resistance of the deposit. Most common equations of gravitational filtration found in literature describe this process in partly idealized conditions in which the influence of factors distorting the process is removed. Therefore, they may not always be applied without the introduction of relevant amendments. For example, changing the value of the deposit resistivity can be expressed, inter alia, as presented in this publication, in dependence on change of the deposit compressibility (compression) coefficient as a factor which distorts the gravitational filtration process.

Andrzej Kulig, Elżbieta Gałązka
Influence of three types of the ground on the emission of environmentally hazardous vapours (on the example of hexane) from spills of flammable and toxic liquids. pp. 51
Keywords: oil spill, evaporation of hexane, air pollution.

SUMMARY

The aim of the research was to demonstrate the relationship between the intensity of evaporation of hexane and the soil type on which the liquid pool is located. After determining the methodology of laboratory tests, the characteristics of mass loss and concentration of vapour over the liquid are shown as a function of flow rate of air over the oil spill. Loss of weight was determined using an electronic laboratory balance, Radwag WPS 1200/C/2 model, in the system’s automatic operation. The weight is set in a wind tunnel with a variable power blower. The concentration of hexane vapour over the liquid surface was determined with a gas analyzer GasmetTM DX-4000, containing a spectrometer FT-IR with Fourier transform infrared spectra. Gathered by the spectrum analyzer, the measurement was recorded by the program’s CALCMET Temet©. During the experiments, data on ambient air and liquid temperatures were measured and collected. The authors noted a significant effect of the type of ground and air velocity over the overflow-hexane on the rate of evaporation of the liquid and consequently the vapour concentrations of pollutants in the air.

Beata Górka-Kostrubiec, Elżbieta Król, Maria Teisseyre-Jeleńska
Magnetic susceptibility as an indicator of traffic pollution in some Warsaw localities. pp. 67
Keywords: traffic pollution, magnetic susceptibility, soil pollution.

SUMMARY

Rapid development of motor transport has been observed in Poland during the last 20 years. A quick increase of numbers of vehicles in cities generates an increase of environmental pollution, mainly in atmosphere and in soil. The magnetic method was used for evaluation of soil pollution along the most crowded streets in Warsaw. The method is based on measurements of magnetic parameters of pollution matter which contains strong magnetic iron oxides correlated with heavy metals presence. Magnetic susceptibility is a sensitive parameter for detection of magnetic grains content. Samples were collected in three localities: Toruńska Route, Modlińska street and Służewiecka Valley street. In each locality, samples were collected from the surface and from the depths of 5, 12 and 20 cm from the road shoulders and from the grass strips separating two directions of traffic lanes. The correlation of observed magnetic susceptibility values of polluted soils with the intensity of vehicle traffic has been confirmed. The distribution of susceptibility values in function of the distance from the road edge and in function of depth of profiles has been presented. On the basis of these results, differences in accumulation of traffic pollution in relation to topography of the area, to distance from road-crossing and influence of plants growing close to roads have been indicated.

No. 60

 

„Thermal processes in natural gas compressor station for pipeline system efficiency improvements”

TABLE OF CONTENTS:

Maciej Chaczykowski
Thermal processes in natural gas compressor station for pipeline system efficiency improvements. pp. 3
Keywords: energy efficiency, exergy analysis, gas transmission system, gas compresor station, gas cooling, organic Rankine cycle (ORC).

SUMMARY

This work attempts to characterize thermal processes in natural gas compressor station leading to efficiency improvements in the pipeline transportation system. The processes include cooling of the gas at the discharge of the compressor station and waste energy recovery on the pipeline compressor drive to generate electricity through a Rankine power cycle. Compressor station technology and its characteristics are briefly presented in sections 1 and 2. Next, the two processes allowing for advances in efficiency are discussed, based on the assumption that the gas turbine driven compressors and the aerial coolers were selected for the compressor station. The irreversibility of the processes associated with gas transmission under different compressor station aftercooler power is investigated in section 3. The exergy method is used to determine the amount of work supplied to the components of the pipeline system and the amount of work that is lost during the gas transmission. For the case study, the Yamal-Europe pipeline is chosen, and the performance of the gas transmission system under different cooler operating set points is investigated. Section 4 concentrates on Organic Rankine Cycle (ORC) based power system and its applicability to waste heat to power conversion in natural gas compressor station. Basic ORC and two variants of regenerative cycle have been considered for the recovery of exhaust heat from a gas turbine. The study is aimed at estimating the thermodynamic potential of the utilization of residual heat under different ORC configurations and with several working fluids employed.

 

 

 

 

2010 year


no. 58

„Present-day problems of Engineering and Protection of Environment”

TABLE OF CONTENTS:

Jeremi Naumczyk, Małgorzata Kucharska, Agata Krzysztoszek, Jan Bogacki
Treatment of effluents arising from aluminium finishing processes pp. 5
Keywords: etching effluents, industrial wastewater treatment, chemical precipitation.

SUMMARY

The aim of the study was to choose optimal parameters for the treatment of effluents arising from aluminium finishing processes. There are four streams of effluents: wasted liquors after etching in HF and H2SO4 solution followed by chromate solution treatment (A) effluents from rinsing of aluminium (B), demineralised and returned to rinsing effluents from ion exchangers regeneration (C) combined A + C effluents (D)
The concentrations of pollutants in effluents A were as follows: pH = 1,6÷2,26, conductivity 7020÷39800 μS/cm, fluorides 1605÷13836 mg/l, sulphates 3300÷16940 mg/l, Cr(VI) 17÷84 mg/l, Cr total 82,5÷264 mg/l, Zn 5,1÷19 mg/l, Ni 1,96÷7,6 mg/l, Al 0,87÷1,9 mg/l. The same components are present in effluent B, but their concentrations are a few hundred times lower.
The first step of the process was Cr(VI) reduction with Na2SO3 or FeSO4 solution, followed by neutralization with NaOH or Ca(OH)2 solution to pH = 8,0, 9,0 and 10,0. The best result was achieved with FeSO4, Ca(OH)2, pH = 10,0 and 5 mg/l of Scanpol 55 as a flocculant. The treatment under these conditions resulted in the lowest concentrations of fluorides, sulphates, metals and lowest conductivity. The lowest fluorides concentration was 21 mg/l. All metals concentrations were < 0,1 mg/l. The same processes conducted with effluents D gave slightly higher final concentrations of these ions. The fact that effluent C has very low concentration of pollutants and effluent D is a combination of effluent A and C resulted in efficient dilution of effluent A. Since better effectiveness of precipitation is observed for condensed effluent, separate purification of effluent A and effluent B is more favorable.

Katarzyna Kaczyńska-Sajko
Impact of inoculation on the biodegradation of petroleum derivatives in the process of decontamination of disposal areas for liquid wastes from producing wells of crude oil pp. 17
Keywords: biodegradation, oil-derivative hydrocarbons, remediation of soil contaminated with petroleum products, pollution by oil products.

SUMMARY

The main goal of the research is to develop a method of treatment of water and soil environment polluted with heavy fractions of crude oil. The results of completed laboratory tests can be converted into technical solutions and applied for the recovery of disposal areas belonging to the oil plant located near the town Gorlice (South-East Poland).
The aim of the study was to determine the impact of selected microorganisms on the biodegradation of petroleum derivatives. During the study, two variants of experiment tested the implementation of indigenous microorganisms (Experiment #1) and the application of the biocatalyst with known microbiological contents (Experiment #2). Results of the three months’ long test with application of the biocatalyst (Experiment #2) have shown that the content of oil-derivative hydrocarbons decreased about 90 percent in comparison to entry samples. Nevertheless, due to the fact that a significant amount (10%) of wastes remain untreated, it is necessary to continue the decontamination process to meet the soil quality standards in accordance with the Regulation of the Minister for the Environment (9 Sep 2002, Dz. U. Nr 165, poz.1359).

Piotr Fabijańczyk, Jarosław Zawadzki
Improvement of soil magnetic susceptibility measurements performed with MS2D Bartington sensor by removing organic litter subhorizon pp. 33
Keywords: magnetic susceptibility, MS2D Bartington, Ol subhorizon.

SUMMARY

Field measurements of soil magnetic susceptibility performed with MS2D Bartington sensor can be influenced by many environmental factors. According to previous studies, thick organic soil layers, which consist of leaves, mosses and other organic matter, can significantly affect MS2D Bartington measurements due to its penetration range, limited to 10 cm.
The goal was to investigate the differences between MS2D Bartington measurements performed with and without preparation of the soil surface, and to study some rescaling techniques that enable to use both types of measurements simultaneously. Several series of measurements were performed with MS2D in a forested area located in the Upper Silesian Industrial Area. Additionally, soil samples were collected and used to determine the concentration of particular heavy metals in soil, and several parameters of the soil profile. Results showed that magnetic susceptibility measured without preparation of the soil surface is less correlated with the heavy metals concentration in soil in comparison with magnetic susceptibility measured after the removal of Ol sub-horizon. Furthermore, such measured values may even be misleading and give no information about the potential soil pollution. However, it is possible to recalculate and use such measurements together with those performed after the removal of Ol sub-horizon.

Zdzisław Chłopek, Magdalena Zimakowska
The models of pollutant emissions from average vehicle speed pp. 47
Keywords: vehicle, air pollutant, environment, modelling

SUMMARY

The software INFRAS and COPERT have been compared in the article. Characteristics of pollutant emission from each vehicle category have been presented. There are dependences of the specific distance emission on the average speed, characterizing the model of vehicle traffic. The analysis results of chosen characteristics of pollutant emission from vehicles are presented in the article.

Radosław Barczak
Sampling methods for olfactometry measurement from diffusive sources pp. 61
Keywords: Olfactometry, odour, hood methods, wind tunnel, flux chamber, odour nuisance.

SUMMARY

This article presents the scope of methods of sampling for olfactometry measurement from different diffusive odorant sources. Methodology of sampling for olfactometry measurements is important but there are no standards for all kinds of odour sources. Different passive sources of odorants were described, as well as factors which influenced the emission rate. Moreover, hood devices and equipment for taking off odour samples were featured. A variety of methods and devices for sampling odour samples may cause discrepancy between data obtained from the same source. Odour concentration could differ several times for different hood devices. Such divergences could cause error with classification of the source of odour nuisance. It is very important because the number of complaints about odour impact from neighbours is still rising.

Izabela Kosińska, Zygmunt Kowalski
Evaluation of municipal waste disposal with the method of process analysis with formulation of cumulated calculation pp. 77
Keywords: environmental evaluation method, municipal solid waste (MSW), landfilling

SUMMARY

Landfilling is an unavoidable element of each municipal solid waste (MSW) system. Technologies such as incineration and mechanical-biological treatment (MBT) produce rests which need to be landfilled. Unfortunately, more than 90% of MSW in Poland is landfilled untreated. Due to EU regulations, this must be changed by the end of 2012. This work presents research results of assessing the potential environmental impact of landfilling of untreated MSW and landfilling of rests from MBT. For this purpose, four variants have been defined.
Results of the analysis prove that landfilling of the rests from MBT has lower environmental impact than landfilling of untreated MSW with landfill gas recovery. Including emissions from MBT installation, landfilling the rests from MBT has slightly lower environmental impact than municipal waste landfilling with landfill gas recovery.

Anna Rolewicz-Kalińska
Possibilities of modeling healthcare waste management system pp. 91
Keywords: healthcare waste, waste management, system analysis

SUMMARY

Healthcare activities can lead to the generation of waste that might be infectious (or hazardous in other ways) and impact human health and the environment. Many factors involved in the hospital waste management system are often linked to one another, which requires a comprehensive analysis to determine the role of each factor in the system. This paper provides a review of methods that can be used in the area of healthcare waste management. The selection of methods includes: multicriteria decision analysis (MCDA), life cycle assessment (LCA) and Bayesian networks (BN). The paper presents benefits and limitations of each method in the field of medical waste management. The models identified above can be used separately (then they usually do not cover all aspects), or together and complement one another. For each method there are examples of practical application in healthcare waste (or similar problems) management. An analysis of tools based on mathematical models to healthcare waste management is found as an important element of making sustainable decisions in this area.

Janusz R. Rak, Krzysztof Boryczko
Importance ranking of elements in system reliability structure pp. 105
Keywords: importance measure, ranking of elements, reliability, water pumping station

SUMMARY

The article outlines issues determination of elements ranking in reliability structure using importance measures. Fussell-Vesely and Birnbauma importance measures, which enable to make ranking of elements, were proposed. The paper includes proposition of a measure of this method for a water pumping station for which the reliability block diagram was determined, probability of working states, Fussell-Vesely and Birnbauma importance measures were calculated. Results enable to point to these elements which are fundamental for reliable work of the water pumping station.

2009 year


no. 55

„Present-day problems of Engineering and Protection of Environment”

TABLE OF CONTENTS:

Anna Kołakowska, Marek Mitosek
Assessment of motion type in pressurised pipe under oscillating water flow (in Polish) pp. 5
Keywords: quasi-unsteady flow, pressure oscillation, pressure loss critical Reynolds number

SUMMARY

The type of motion under oscillating water flow is analysed in the paper. Oscillatory liquid flow in pressurised pipes may be considered as a type of alternate or unidirectional motion. Alternate flow involves the phenomenon of water hammer and swinging of mass in a pipe. Flow of blood in arteries, as well as numerous cases of changes in time flows, e.g. in water-pipe networks, may be regarded as oscillation - unidirectional motion. For small amplitudes of stream velocity, flows are treated as quasi-steady flow. In oscillation flows, five types of zones of motion may be distinguished: laminar, distorted laminar, weakly turbulent, conditionally turbulent and fully turbulent. Due to difficulties in determination of phase boundaries of the zones, theoretical and experimental considerations have concentrated on the estimation of critical value of the Reynolds number Rekr when flow becomes fully turbulent. Influence of oscillation frequency on the value of Rekr is analysed in the paper. It has been stated that for small values of frequency, the critical value Rekr is comparable with the critical Reynolds number for steady flow. When the oscillation frequency increases, the critical value Rekr may become higher. An interesting issue is estimation of pressure loss when laminar and turbulent oscillation flows occur. This is particularly important when quasi-steady flow, typical for water-pipe network, is considered. At present, experimental research is carried out to estimate influence of velocity oscillation on the pressure loss in pressurised pipes made of different materials.

Marian Kwietniewski, Julia Trymucha
Evaluation of failure frequency of an open cooling system in a conventional power station, using multifactor analysis (in Polish) pp. 17
Keywords: cooling system, ,multifactor analysis, conventional power industry

SUMMARY

The article outlines the issues of research processes of electricity generation in the conventional power industry from the perspective of their efficient operation, namely their reliability. Failure frequency has been determined on the basis of multifactor analysis. A cooling system has been described, and research based on the analysis of failure frequency of the devices which constitute the cooling system has been conducted. As a result of the research, classification of the observed damage has been presented according to the following types: Uu – device failure (disturbance), Wu – device shutdown, and Wb – unit shutdown. Furthermore, the methodology of log-linear analysis has been presented along with the final results. As a result of multifactor analysis, it has been stated that in case of cooling systems, single-factor and two-factor interactions are involved. Single-factor interactions are involved in case of devices as well as particular types of failures; whereas two-factor interactions arise between devices and types of failure, devices and technological lines, types of failure and technological lines.

Stanisław Biedugnis, Sebastian Zieliński
Modelling of functioning and dependence of modules of a wastewater
treatment plant (in Polish) pp. 33
Keywords: CAD – Computer Aided Designing, sewage (wastewater) treatment, sewage (wastewater) treatment plant, numerical analysis in environmental engineering, treatment process modelling

SUMMARY

The basic construction of a model describing the proper functioning of a wastewater treatment plant and dependence between its modules has been presented in this paper. The model is intended for implementation in future as a computer program for designing and analysing wastewater treatment plants.

Yuan Bai, Bronisław Bartkiewicz
Removal of heavy metals from wastewater using ion exchange resin Amberjet 1200H columns pp. 43
Keywords: heavy metals, ion-exchange, resin, column

SUMMARY

The aim of this study was the removal of Cu2+, Zn2+ by ion-exchange resin Amberjet 1200H in flow condition. The adsorption characteristics of each metal onto the resin were accurately described by Freundlich isotherms. Ion exchange capacities of the heavy metals on the ion exchange resin were studied in single metal solution. The capacities of sorption were 2.13 eq Zn/l, and 2.74 eq Cu/l respectively, and the ion exchange on resin follows pseudo-first-order kinetics.

Zdzisław Chłopek, Magdalena Zimakowska
Characteristics of pollutant emission from vehicle internal combustion engines (in Polish) pp. 53
Keywords: emission, characteristics of pollutant emission, emission from vehicle engines, pollutants

SUMMARY

Characteristics of pollutant emission from each category of vehicle have been represented in the paper. These are the dependencies of specific distance emission on the average speed, characterizing the model of vehicle traffic. Characteristics of pollutants have been obtained on the basis of results from the software of INFRAS AG. The analysis results of chosen characteristics of pollutant emission from vehicles are presented in the paper.

Krystyna Lelicińska-Serafin
Flow resistance of gases through a biofilter filled with stabilized materials from municipal waste (in Polish) pp. 67
Keywords: biofiltration, flow resistance, stabilized municipal waste

SUMMARY

Biofiltration is the most commonly used system on a technical scale among biological methods of gas purification. Operational costs and effectiveness of biofiltration are closely related to flow resistance of gases through the filling material. The aim of the paper has been to study flow resistance of gases through filter bed depending on loading rate and the humidity of the filling material. Stabilized material from municipal waste after the mechanical-biological treatment (DANO system) was used as filling material. This material is characterized by good absorbtion properties, large number of microorganisms, availability in Poland and low costs. In this work the usefulness of this material for filter beds with low pressure drop has also been proved.

Bartosz Wąsikowski
Hydrogels — new material helping in waste disposal recultivation. Literature review (in Polish) pp. 83
Keywords: hydrogels, recultivation, waste disposals

SUMMARY

The paper presents properties of hydrogels and the potential possibilities of utilizing them in the process of waste disposals rehabilitation, namely: techniques of waste disposal recultivation, using hydrogels to protect plants from falling out, predicted influence of hydrogels on plants, possible problems occurring in the process of recultivation.

no. 56

„Present-day problems of Engineering and Protection of Environment”

TABLE OF CONTENTS:

Maria Łebkowska
Occurrence and ecotoxicity of selected pharmaceuticals in water Environment (in Polish) pp. 5
Keywords: drugs, ecotoxicity, water biocenosis

SUMMARY

This article presents a review of ecotoxicity data of selected drugs and the occurrence of pharmaceuticals in water environment. Residues of various drugs and their metabolites are carried with wastewater to municipal wastewater treatment plants, and further to water and drinking water. The majority of these compounds cause no negative acute effects, but trigger strong chronic responses at concentrations close to those found in surface water. It was suggested that the chronic bioassays performed over the life-cycle of various organisms and chronic values of PNEC of the drugs may be the most appropriate basis for risk assessment. An absolute prerequisite to this idea is the execution of long-term testing of potential chronic effects of pharmaceuticals including histopathological and immunohistological criteria.

Ewa Karwowska , Monika Zygmunt, Anna Balik, Jacek Wąsowski
The influence of pre-acidification on the effectiveness of zinc bioleaching from
digested sludge (in Polish) pp. 13
Keywords: digested sludge, pre-acidification, bioleaching

SUMMARY

Bioleaching is an effective method of heavy metals elimination from sludges formed during various stages of wastewater treatment process. In sludge from the methane fermentation process, high amounts of heavy metals occur. This pertains to zinc in particular, whose concentrations reach grams per kilogram of the sludge dry weight.
The aim of this research was to estimate the influence of sludge pre-acidification on zinc bioleaching efficiency. Some organic (citric, lactic and acetic acid) and inorganic (HCl, H2SO4) acids were taken into account. It was revealed that pre-acidification allows to increase the process effectiveness as well as to shorten the process period. The best results were obtained for citric acid. The level of metal elimination was about 80- 90%.

Mirosław Szyłak-Szydłowski, Anna Grabińska-Łoniewska
Neutralization methods of municipal landfills leachates (in Polish) pp. 21
Keywords: BOD, COD, landfill leachates, SBR, municipal landfills, waste, oxidation

SUMMARY

The paper presents the scope of methods used for neutralization of leachates from municipal landfills, such as leachates recirculation in the landfill, carry-of into sewage system, chemical and biological methods in aerobic, anaerobic and aerobic-anaerobic conditions, as well as hybrid solutions.

Andrzej Kulig, Krystyna Ossowska-Cypryk
Comparative analysis of results derived from research into the degree of microbiological air pollution at sampling based on sedimentation and impact or filtration methods (in Polish) pp. 45
Keywords: air sampling, airborne bacteria, airborne moulds, bioaerosols, colony forming unit, fungi, impact (collision) method, method of impingement into a liquid, microorganisms, sedimentation method

SUMMARY

In microbiological examination of air, apart from the need to choose a sampling method, it is also necessary to assess the method in terms of its microorganism capturing effectiveness and errors occurring in the process. The variety of air sampling methods and equipment types used for microbiological examination by individual authors leads to the situation that the results obtained by means of those methods and equipment are not unequivocal. Since the results are far from being homogenous, it is difficult to assess the degree of microbiological air pollution objectively.
For many years of research work carried out at the Warsaw University of Technology, Institute of Environmental Engineering Systems (1970-2007), a lot of attention has been paid to the methodological issues in the microbiology of air. Within the framework of the research activity done initially at the Engineering and Sanitary Environmental Protection Division and, later on, at the Environmental Biology Division and the Urban Environment Protection Division, numerous experiments were conducted to compare the effectiveness of the techniques applied to capture microorganisms from the air in samples collected by means of sedimentation, impact and filtration methods.
The paper shows the results of comparative research carried out in the surroundings of various bioaerosol sources, mainly wastewater treatment plants and animal breeding facilities, in unpolluted air, in buildings and in a laboratory. The results of the analysis point to the need to conduct comparative research, as in diverse environmental conditions the relationships among numerical microorganism concentrations obtained by means of various methods are not constant. Moreover, as a result of technological development of the equipment used in individual research methods (slit samplers, impingers etc.) its microorganism capturing capacity has changed and this change has had a direct influence on the results of the given research.

no. 57

„Present-day problems of Engineering and Protection of Environment: modeling of sewerage systems”
[Ed. Marian Kwietniewski, Jerzy Sawicki, Marek Zawilski]

TABLE OF CONTENTS:

Marek Zawilski, Grażyna Sakson
Topical problems of sewerage systems' model ling (in Polish) pp. 5
Keywords: computer modelling, urban sewerage, calibration
SUMMARY
In the paper the present state-of-art in the field of sewerage systems’ modelling is presented. Models being in use, modelling range, especially considering the so-called integrated option, are reviewed. A special attention is paid on the stage of creation of a model and especially on the necessity to create a database suitable for modelling and calibration. Types of modelling errors and their significance for final results are discussed. Also, practical applications of digital models as well as research aims which should be undertaken in the future, are presented.

Jerzy Sawicki
Selection of sewerage model precision level (in Polish) pp. 19
Keywords: sewerage, hydraulic dimensioning, designing

SUMMARY

The paper is devoted to the question of the proper choice of the mathematical model, describing the sewerage system. The conformity between physical aspects of this system and individual features of the model serves as a criterion of the final decision. The following set of basic model has been considered: unsteady and non-uniform flow, steady and non-uniform flow, steady and uniform flow. The significance of the proper choice of the model has been illustrated by means two examples – determination of characteristic rain run-off and dimensioning of distributing chambers. The meaning of professional qualifications and technical consciousness of specialists was underlined in conclusions.

Marcin Skotnicki, Marek Sowiński
Verification of subcatchment hydraulic width evaluation method exemplified by real urban catchment (in Polish) pp. 27
Keywords: urban catchment, rainfall-runoff model, hydraulic width of subcatchments

SUMMARY

In the framework of analysis presented in the paper an influence of hydraulic width of subcatchment on runoff from urban catchment was investigated. Based on literature review two approaches of hydraulic width evaluation were compared. In the first one a hydraulic width was computed as a function of geometric dimensions of each subcatchment. In the second approach a hydraulic width of a subcatchment was evaluated based on assumed constant (for all subcatchments) length of runoff path from impervious part of its surface. A runoff path length was determined as multiplication of a distance between inlets to sewers. This analysis was performed for real urban catchment which is used for research purpose from several years by our Institute. A rainfall-runoff model based on SWMM5 package was applied for computation of runoff from this catchment. Simulations were performed for historical rainfalls from the period 2007 – 2008. An assessment of approaches of hydraulic width evaluation was based on comparison of computed and measured runoff hygrograms. For both approaches a temporal pattern of computed hygrograms agrees with the pattern of measured hygrograms. The first approach allows for computation of maximal values of runoff with an accuracy of approx. 15 %. The same accuracy was obtained in the second approach for the length of runoff path in the interval 50 – 75 m.

Paweł Licznar, Janusz Łomotowski, Monika Paluch-Puk
Rainfall measurements for canalization design Leeds (in Polish) pp. 45
Keywords: rainfall measurements, hyetographs, sewerage

SUMMARY

Currently applied methods of atmospheric precipitations measurements were described. Own construction raingauges were presented. The studies made with the use of own construction imactometer showed the relationship between rainfall depth and rainfall kinetic energy. It was proved that hyetographs were the random function and their variability depended on assumed calculation conditions.

Marcin Leśniewski
Set-up of flow monitoring system of Warsaw combined sewer system network (in Polish) pp. 59
Keywords: flow measurement, monitoring, sewerage

SUMMARY

In the year 2008 flow monitoring system for combined sewer network was started up. It is first such system in Poland but now exist many similar systems in cities in developed countries. Distinctive feature of Warsaw measurement is that it was implemented in very difficult technical conditions in sewers. In this article process of planning and set-up of flow monitoring system was presented for use in other cities in Poland. It was considered: measurement point placement in the network, choosing right measurement and mounting technology, design and getting permissions process, mounting and start-up monitoring devices, measurement verification.

Maciej Mrowieć
Influence of the spatial variability of the rainfall on the urban drainage systems (in Polish) pp. 67
Keywords: drainage system, rainfalls, spatial variability

SUMMARY

The papers presents results of the investigations focused on dynamic properties of a rainfall events. Influence of rainfall movement on the urban drainage system performance is poorly described in a literature, so methods used by engineers don’t consider the spatial variability of the rainfalls. The main source of the rainfall data for investigations was the Intensity-Duration-Frequency (IDF) curves carried out by Institute of Meteorology and Water Management. Model of virtual catchment, divided in 10 unit subcatchemnts (24ha each), was done using widely-known software EPA SWMM5. Overall, 126 hydrodynamic simulations were done, considering the variable values of the rainfall duration, intensity (based on a return period), direction and speed of rainfall movement over the catchment (2÷10 m/s). Obtained results allow to formulae the conclusion that both: direction and speed of the rainfall have significant influence on the peak values of the flow-rate as well as on the time of concentration. For the rainfalls of the short duration, moving over the catchment in the direction accordant to the general flow direction in the pipes, the peak flow-rates were greater than 100% in comparison to a flow-rates obtained for a static conditions (uniform rainfall over the whole catchment).

Andrzej Kotowski
Credibility of basis of storage unit modelling for storm water (in Polish) pp. 79
Keywords: sewage system, storage unit, modelling

SUMMARY

In this study we demonstrated on examples significant quantitative differences between Polish and German methods used to define the rate of representative rain to model the volume of storage unit. Namely, new formulas developed by IMGW on the height of rainfall, which were based on rain measurement in years 1960-1990, are not sufficient with reference to the frequency of annual rainfall, where the reservoir volume are almost twice lower than those counted with application of Błaszczyk equation and nearly two and a half times lower than those counted from Reinhold equation. It has its consequences in sizing drainage area according to recommendation of PN-EN 752 standard from years 2000 and 2008 – following the example of DIN-EN 752 standard (1996), adjusted to Reinhold equation – influencing directly on major frequency of outflow from sewage system in Poland. In the study we pointed on methods of temporary and future solution of this problem, adapting to the European Committee for Standardization (CEN), unification requirements in the field of protection the area from outflow from sewage systems, what will be obligatory in member states of European Union.

Maria Orłowska-Szostak, Ryszard Orłowski
Dimensioning of pressure sewage system based on carefully selected authoritative situations (in Polish) pp. 93
Keywords: pressure sewage system, authoritative simultaneous operation of the pump stations, extreme operational situations, system dimensioning

SUMMARY

In the paper has been presented a precise method of dimensioning of pressure sewage system. The most essential element of the method is searching of three different groups of operational situations in the system. These are: (1) the situations that are authoritative from the point of view of the size of possible water hammer, (2) the situations that are authoritative from the point of view of the self-cleaning velocities in pipelines, (3) the situations that are authoritative from the point of view of the pump selection. The two first groups of the operational situations (defined individually for each segment between the nodes of the pipeline network) are used for determining the corridor (range) of technically feasible diameters of pipelines along the network in the pressure system. Inside the corridor we are searching the optimum solution. The analysis of the situations (different for individual pump stations) of the third mentioned group leads to evaluating maximum required delivery head of each individual pump station at predetermined, satisfactory high level of reliability. When searching the authoritative combinations of simultaneous operation of the pump stations in all above situations the authors used theory of probability. Finally a case study has been presented.


 

 

 

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