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Tiku T. Tanyimboh - One of the best experts on this subject based on the ideXlab platform.
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Active Control of Combined Sewer Systems Based on Flow and Water Quality
New Trends in Urban Drainage Modelling, 2018Co-Authors: Tiku T. TanyimbohAbstract:Discharges from urban wastewater systems are the main source of pollution for inland and coastal waters, and intermittent unsatisfactory discharges from combined Sewer systems have been recognized as a major environmental concern. The aim of the research was to investigate active system control of an Interceptor Sewer system. The dynamic multiobjective optimization approach developed considered the unsteady flow and pollution load in the Sewers and wastewater treatment costs. Contrary to previous approaches in the literature, the combined effect of the various primary contaminants was addressed by means of the effluent quality index.
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Evolutionary Multi-Objective Optimal Control of Combined Sewer Overflows
Water Resources Management, 2015Co-Authors: Upaka S. Rathnayake, Tiku T. TanyimbohAbstract:This paper presents a novel multi-objective evolutionary optimization approach for the active control of intermittent unsatisfactory discharges from combined Sewer systems. The procedure proposed considers the unsteady flows and water quality in the Sewers together with the wastewater treatment costs. The distinction between the portion of wastewater that receives full secondary treatment and the overall capacity of the wastewater treatment works (including storm overflow tanks) is addressed. Temporal and spatial variations in the concentrations of the primary contaminants are incorporated also. The formulation is different from previous approaches in the literature in that in addition to the wastewater treatment cost we consider at once the relative polluting effects of the various primary contaminants in wastewater. This is achieved by incorporating a measure of the overall pollution called the effluent quality index. The differences between two diametrically opposed control objectives are illustrated, i.e. the minimization of the pollution of the receiving water or, alternatively, the minimization of the wastewater treatment cost. Results are included for a realistic Interceptor Sewer system that show that the combination of a multi-objective genetic algorithm and a stormwater management model is effective. The genetic algorithm achieved consistently the frontier optimal control settings that, in turn, revealed the trade-offs between the wastewater treatment cost and pollution of the receiving water.
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Multi-objective optimization of urban wastewater systems
2012Co-Authors: Upaka Rathnayake, Tiku T. TanyimbohAbstract:Combined Sewer overflows (CSOs) are one of the environmental problems in many cities. Damage to the natural environment by these CSOs is considerable. Controlling urban wastewater systems is one possible way of addressing the environmental issues from CSOs. However, controlling urban Sewer systems optimally is still a challenge, when considering the receiving water quality effects. In this study, a multi-objective optimization approach was formulated considering the pollution load to the receiving water from CSOs and the cost of the wastewater treatment. The optimization model was tested using an Interceptor Sewer system. Results from the study show some promising findings.
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Optimal control of combined Sewer systems using SWMM 5.0
Urban Water, 2012Co-Authors: Upaka Rathnayake, Tiku T. TanyimbohAbstract:Combined Sewer networks carry wastewater and stormwater together. Capacity limitation of these Sewer networks results in combined Sewer overflows (CSOs) during high-intensity storms. Untreated CSOs when directly discharged to the nearby natural water bodies cause many environmental problems. Controlling urban wastewater systems is one possible way of addressing the environmental issues from CSOs. However, controlling urban Sewer systems optimally is still a challenge, when considering the receiving water quality effects. In this study, a multi-objective optimization approach was formulated considering the pollution load to the receiving water from CSOs and the cost of the wastewater treatment. The optimization model was tested using an Interceptor Sewer system. The results demonstrate the benefits of the multi-objective optimization approach and its potential to establish the key properties of a range of control strategies through an analysis of the various tradeoffs involved.
Swolkień Justyna. - One of the best experts on this subject based on the ideXlab platform.
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Zastosowanie programu komputerowego "Dyspozytor" jako narzędzia w procesie regulacji rozpływu wody w kolektorze "Olza"
1Co-Authors: Swolkień Justyna.Abstract:Tyt. z nagłówka.Bibliogr. s. [93].Dostępny również w formie drukowanej.STRESZCZENIE: W artykule opisano zastosowanie programu komputerowego "Dyspozytor" do regulowania procesu rozpływu wód kopalnianych odprowadzanych za pośrednictwem kolektora "Olza" do rzeki Odry. Brak regulacji rozpływu powoduje drastyczne skoki stężeń jonów chlorkowych i siarczanowych, co jest zabójcze dla ekosystemu rzeki. Wykonane obliczenia komputerowe pokazują, iż utrzymanie stabilnych stężeń wspomnianych jonów w rzece, przy określonym przepływie, możliwe jest tylko i wyłącznie przy odpowiednio dobranych parametrach pracy wskazanych obiektów systemu. Odpowiednia regulacja pozwala również na zachowanie w miarę niskich ciśnień na wybranych połączeniach sieci kolektora, co znacząco poprawia jego energochłonność. SŁOWA KLUCZOWE: program komputerowy "Dyspozytor", regulacja rozpływu wód, kolektor "Olza", normy czystości, stężenia jonów chlorkowych i siarczanowych, ciśnienia pompowania, wody kopalniane. ABSTRACT: The article treats about the usage of "Dyspozytor" application in mine waters' flow regulation inside the "Olza's" Interceptor Sewer. Lack of its regulation is a main reason for huge variations of chlorides and sulphates concentration in the Odra river what in the end drives its ecosystem to the total destruction. Computer calculations show that in order to remain stable chlorides and sulphates concentration it is necessary for each Interceptor Sewer's object to work with a proper working parameters'. The computer program, together with "Olza's" Interceptor Sewer, helps to regulate water flow from each mine. It determines what kind of water class is possible to obtain taking into consideration river flow and its earlier contamination. Thanks to it is possible to maintain constant chlorides and sulphates concentration due to the exact water class. It is also possible to maintain low pressure in the Interceptor Sewer's pipelines what improves its energy consumption. KEYWORDS: computer program "Dyspozytor", chlorides and sulphates concentration, river flow regulation, "Olza" Interceptor-Sewer, mine waters, water classes, pumping pressure
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Stan zasolenia rzeki Odry za kolektorem "Olza" w zależności od jej przepływu i warunków atmosferycznych
1Co-Authors: Swolkień Justyna.Abstract:Tyt. z nagłówka.Bibliogr. s. [162].Dostępny również w formie drukowanej.STRESZCZENIE: W artykule skupiono się na określeniu zależności zasolenia rzeki Odry od jej przepływu i warunków atmosferycznych. Silne zasolenie rzeki jest wynikiem wprowadzania do niej wód kopalnianych odprowadzanych z obszaru południowo-zachodniej części GZW za pośrednictwem kolektora "Olza". W artykule podzielono przepływy na pięć kategorii i przypisano im możliwe do uzyskania klasy czystości ze względu na jony chlorkowe. Na podstawie wyznaczonych za pomocą programu komputerowego "Dyspozytor" marginesów przepływu i na podstawie przynależności rzeki do danej klasy czystości określono, jaki wpływ na stan zasolenia wywiera proces retencjonowania i dozowania wody kopalnianej z kolektora. Ustalono również, w jakich warunkach można dotrzymać najwyższych, a w jakich najniższych norm czystości w rzece ze względu na jony chlorkowe. SŁOWA KLUCZOWE: stężenie jonów chlorkowych, przepływ rzeki, kolektor "Olza", wody kopalniane, chłonność rzeki. ABSTRACT: This article treats about the state of salinity in Odra river in connection with its flow and atmospheric conditions. Very high chlorides concentration in the river is a consequence of dropping into its water highly contaminated mine waters form the south - western part of Upper Silesian Coal Basin. Mine waters are transported through the Interceptor Sewer called "Olza". The author divides the river flows on the five categories and classifies them due to the exact water classes. Taking into consideration flow margins calculated by using the computer program called "Dyspozytor" and river absorptiveness due to the specific water class, it was possible to estimate the influence of dosing and retaining on the state of river waters salinity. It was also possible to state in which conditions there is a chance to keep the highest water class and in which there is no such a chance. KEYWORDS: chlorides concentration, "Olza" Interceptor-Sewer, river flow, mine waters, river absorptiveness
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Wpływ modernizacji systemu retencyjno-dozującego "Olza" na jakość wód rzeki Odry, Olzy i Leśnicy
1Co-Authors: Swolkień Justyna.Abstract:Tyt. z nagłówka.Bibliografia s.114.Dostępny również w formie drukowanej.ABSTRACT: This article treats about the influence of dropping system "Olza" modernization on the Odra, Lesnica and Olza rivers ecosystem. Both, Leśnica and Olza were the most jeopardize ones, taking into consideration the fact that the mine waters were directly thrown to their waters. Strongly contaminated, mostly with chlorides and sulphates, mine waters, transported through the Interceptor-Sewer, managed to destroy the whole rivers ecosystem. Huge chloride fluctuations were the cause of biological balance dysfunction. Most of animals and plants species were destroyed. The brake through came after the new dropping system was activated. The new system was placed in the bottom of Odra river and was equipped with 51 nozzles settled down between two river banks. The new system allowed to eliminate the contamination of the Leśnica and Olza rivers and prevented their flora and fauna from total distraction. It also allowed to mix the mine and the river waters just after the drop. It led to the elimination of huge chloride fluctuation in the Odra river and had a huge impact on its quality improvement. KEYWORDS: "Olza" retaining-dose system, Interceptor-Sewer, river ecosystem, water quality, mine waters, odra river contamination, chlorides, sulphates, dropping system modernization, water classes. STRESZCZENIE: W artykule przedstawiono zagadnienia związane z wpływem przeprowadzonej modernizacji sytemu retencyjno-dozującego (kolektora) "Olza" na jakość wód rzeki Odry, Olzy i Leśnicy. Silnie zanieczyszczone jonami chlorkowymi, siarczanowymi wody kopalniane odprowadzane z kopalń południowo-zachodniej części Górnośląskiego Zagłębia Węglowego (GZW), za pośrednictwem kolektora, wywierają niekorzystny wpływ na ekosystem rzeczny. Szczególnie groźne są silne wahania stężeń jonów chlorkowych, które zaburzają równowagę biologiczną eko-systemu, narażając na wyginięcie różne gatunki roślin i zwierząt. Uruchomienie bezpośredniego odprowadzania wód kopalnianych do rzeki Odry za pomocą systemu zrzutowego zainstalowanego w dnie rzeki zapewniło odpowiednie wymieszanie wód kopalnianych z jej wodami na krótkim 100-metrowym odcinku. System wyposażony jest w 51 dysz rozmieszczonych między prawym i lewym brzegiem rzeki. Takie rozwiązanie pozwoliło uniknąć silnych wahań stężeń, przede wszystkim jonów chlorkowych, i uchroniło florę i faunę rzeki Odry przed wyniszczeniem. Uruchomienie zmodernizowanego odcinka kolektora wyeliminowało również konieczność odprowadzania wód kopalnianych do Odry za pośrednictwem rzek Leśnicy i Olzy. Przyczyniło się to do znaczącej poprawy jakości wód tych rzek i powolnego odbudowania się ich ekosystemu. SŁOWA KLUCZOWE: system retencyjno-dozujący (kolektor) "Olza", ekosystem rzeczny, wody dołowe, jakość wód, zanieczyszczenia rzeki Odry, stężenia jonów chlorkowych i siarczanowych, modernizacja systemu zrzutowego, instalacja zrzutowa, klasy czystości wód
Richard Ashley - One of the best experts on this subject based on the ideXlab platform.
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erosion mechanisms in combined Sewers and the potential for pollutant release to receiving waters and water treatment plants
Water Science and Technology, 2002Co-Authors: T D Mcllhatton, Richard Ashley, Ruben Sakrabani, R BurrowsAbstract:The problems associated with solids in Sewerage systems result in common difficulties such as blockages and flooding and the subsequent maintenance requirements have been well documented. Concerns regarding pollutant release have also been demonstrated, with the contribution from in-Sewer solids to the quality of the flow during a storm event being especially significant. These events known as “foul flushes” in combined Sewers typically occur in the initial period of storm flows, when the concentration of suspended sediments and other pollutants are significantly higher than at other times. Traditionally impacts from these events have been related to the suspended solids phase of the flow passing through a CSO structure. It is now apparent that much of the suspended load originates from solids eroded from the bed. The “near bed solids” which are re-entrained into the flow, together with solids eroded from the bulk bed, account for large changes in the suspended sediment concentration under time varying flow conditions. The influence of these eroded solids and their potential impact on receiving waters and treatment plants will be reviewed using data obtained from field studies carried out in the main Dundee Interceptor Sewer in Scotland. This paper describes some of the methods employed to investigate the characteristics of the pollutants associated with solids erosion in combined Sewers.
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An Appraisal of Suspended Sediment Transport Modelling Methods for an Interceptor Sewer
Water Science and Technology, 1993Co-Authors: B. P. Coghlan, Richard Ashley, Christopher JefferiesAbstract:The data from a two and a half year field study were used to assess the performance of various suspended sediment transport modelling methods. The models selected for this purpose were those proposed by Ackers-White and by Sonnen and these have been assessed following site specific calibrations. A modified version of the Ackers-White model and a rating curve based on a regressional analysis of flowrate versus total suspended solids were also tried. The calibrated verion of the Ackers-White model was selected as giving the best overall accuracy for storm and dry weather conditions. A validation of the selected model using further data for the same site gave approximately 69% of predicted concentrations between 1/2 and 2 times the observed values.
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The Deposition and Erosion of Sediments in Sewers
Water Science and Technology, 1992Co-Authors: Richard Ashley, D. J. J. Wotherspoon, M. J. Goodison, I. Mcgregor, B. P. CoghlanAbstract:The problems caused by sediments in Sewers are now universally acknowledged. A number of countries have set up comprehensive programmes to study all aspects of Sewer sediments; their occurrence, nature and movement. In the UK the Water Research centre and others have funded a comprehensive study of the sediments in the Dundee Sewer system. The rate of sedimentation and the yield strength of the sediments have been investigated and considered in terms of the subsequent erosion by increasing flows. The sediments have been found to be cohesive in nature and highly resistant to erosion in the main Interceptor Sewer, whereas in the trunk Sewers the sediments are more granular and less cohesive in nature. A Sewer classification system is suggested which is based on physical characteristics, and also relates to the nature of the sediments deposited, and the bed-load material conveyed close to the bed.
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Rheological Measurement of the Yield Strength of Combined Sewer Sediment Deposits
Water Science and Technology, 1992Co-Authors: D. J. J. Wotherspoon, Richard AshleyAbstract:A definition for a working value of yield stress for sediment deposits with a cohesive nature is provided through the application of rheometrical techniques. An applied stress technique was utilised to examine the yield characteristics of sixty-one sediment samples obtained from a combined Interceptor Sewer. Yield strength values obtained were related to the solid/liquid phase relationships for these sediment samples. It is suggested that the yield strength presented can provide a suitable definition for material available for erosion from the sediment bed.
David Butler - One of the best experts on this subject based on the ideXlab platform.
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Self-Cleansing Sewer Design Based on Sediment Transport Principles
Journal of Hydraulic Engineering, 2003Co-Authors: David Butler, Richard May, John AckersAbstract:The need for Sewers to carry sediment has been recognized for many years. Traditionally, a minimum ''self-cleansing'' velocity was specified and, although this approach had been successful in many cases, it was appreciated that a minimum velocity— unrelated to the characteristics and concentration of the sediment or to other aspects of the hydraulic behavior of the Sewer—could not properly represent the ability of Sewer flows to transport sediments. During the 1980's, sediment transport theory had been increasingly applied to the design of Sewers, particularly in major Interceptor Sewer schemes. But, in the absence of any universally recognized guidance, the design methodologies and criteria adopted were developed on a project-by-project basis, building on the increasing experience and understanding of the subject of the designer. In recognition of this, a research project was initiated by the U.K.'s Construction Industry Research and Information Association to develop a new design methodology for Sewers, which would take advantage of the available knowledge ~mostly laboratory derived! on sediment mobility and the effects of sediment deposition on the hydraulic performance of Sewers. This paper describes the main findings of the project and summarizes the recommended design guidance.
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Designing Sewers to Control Sediment Problems
Urban Drainage Modeling, 2001Co-Authors: John Ackers, David Butler, Daniel LeggettAbstract:The need for Sewers to carry sediment has been recognised for many years. Traditionally a minimum 'self-cleansing' velocity was specified in the UK and, although this approach had been successful in many cases, it was appreciated that a minimum velocity unrelated to the characteristics and concentration o f the sediment or to other aspects o f the hydraulic behaviour of the Sewer could not properly represent the ability of Sewer flows to transport sediments. In particular, it was already known that a higher flow velocity would needed to transport a greater concentration of sediment, or to transport a given concentration of sediment in a large Sewer than in a small Sewer. During the 1980s, sediment transport theory had been increasingly applied to the design o f Sewers, particularly in major Interceptor Sewer schemes. But, in the absence o f any universally recognised guidance, the design methodologies and criteria adopted were developed on a project-by-project basis, building on the designers' increasing experience and understanding o f the subject. In recognition o f this, a research project was initiated by CIRIA (Construction Industry Research and Information Association) in 1992, to develop a new design methodology for Sewers, which would take advantage o f the available knowledge on sediment mobility and the effects o f sediment deposition on the hydraulic performance of Sewers. The project culminated with the issue o f CIRIA Report 141 (Ackers, Buffer and May, 1996). This paper describes the main findings o f the project and summarises the design guidance contained in the report.
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In-Sewer biodegradation study at the Costa do Estoril Interceptor system
Urban Water, 2000Co-Authors: Maria Do Céu Almeida, David Butler, José Saldanha MatosAbstract:Abstract Understanding and quantifying the transformations of wastewater during transport in Sewers is an important prerequisite to engineering and improving the performance of the integrated urban wastewater system. This paper describes experiments, which were carried out in a Portuguese Interceptor Sewer to quantify changes in different water quality determinands as a result of the combined activity of suspended and attached biomass. The focus is on dry weather flows under aerobic conditions. The highest reduction was found for dissolved COD, which includes an important fraction of easily biodegradable matter. The results are not directly applicable to other systems but indicate the range of values that can be expected under similar conditions.
John Ackers - One of the best experts on this subject based on the ideXlab platform.
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Self-Cleansing Sewer Design Based on Sediment Transport Principles
Journal of Hydraulic Engineering, 2003Co-Authors: David Butler, Richard May, John AckersAbstract:The need for Sewers to carry sediment has been recognized for many years. Traditionally, a minimum ''self-cleansing'' velocity was specified and, although this approach had been successful in many cases, it was appreciated that a minimum velocity— unrelated to the characteristics and concentration of the sediment or to other aspects of the hydraulic behavior of the Sewer—could not properly represent the ability of Sewer flows to transport sediments. During the 1980's, sediment transport theory had been increasingly applied to the design of Sewers, particularly in major Interceptor Sewer schemes. But, in the absence of any universally recognized guidance, the design methodologies and criteria adopted were developed on a project-by-project basis, building on the increasing experience and understanding of the subject of the designer. In recognition of this, a research project was initiated by the U.K.'s Construction Industry Research and Information Association to develop a new design methodology for Sewers, which would take advantage of the available knowledge ~mostly laboratory derived! on sediment mobility and the effects of sediment deposition on the hydraulic performance of Sewers. This paper describes the main findings of the project and summarizes the recommended design guidance.
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Designing Sewers to Control Sediment Problems
Urban Drainage Modeling, 2001Co-Authors: John Ackers, David Butler, Daniel LeggettAbstract:The need for Sewers to carry sediment has been recognised for many years. Traditionally a minimum 'self-cleansing' velocity was specified in the UK and, although this approach had been successful in many cases, it was appreciated that a minimum velocity unrelated to the characteristics and concentration o f the sediment or to other aspects o f the hydraulic behaviour of the Sewer could not properly represent the ability of Sewer flows to transport sediments. In particular, it was already known that a higher flow velocity would needed to transport a greater concentration of sediment, or to transport a given concentration of sediment in a large Sewer than in a small Sewer. During the 1980s, sediment transport theory had been increasingly applied to the design o f Sewers, particularly in major Interceptor Sewer schemes. But, in the absence o f any universally recognised guidance, the design methodologies and criteria adopted were developed on a project-by-project basis, building on the designers' increasing experience and understanding o f the subject. In recognition o f this, a research project was initiated by CIRIA (Construction Industry Research and Information Association) in 1992, to develop a new design methodology for Sewers, which would take advantage o f the available knowledge on sediment mobility and the effects o f sediment deposition on the hydraulic performance of Sewers. The project culminated with the issue o f CIRIA Report 141 (Ackers, Buffer and May, 1996). This paper describes the main findings o f the project and summarises the design guidance contained in the report.