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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Generalized, Steady-State Simulation of Wastewater Treatment Plants

Tan, Patrick 01 1900 (has links)
<p> Laboratory and field measurements were combined with theory in developing models for the various wastewater treatment processes. Some assumptions were made, both in an attempt to simplify the complex mechanisms encountered and to explain known experiences and observations. </p> <p> Models for a primary settling tank, a secondary settling tank, a generalized aerobic biological sludge treatment scheme, an anaerobic digestion system and several other unit processes have been developed. The generalized aerobic biological sludge treatment scheme is an attempt to describe in one physical package, all the various activated sludge process modifications. </p> <p> The executive system used is GEMCS · together with its library of subroutines, such as CONTLl, SEPAOl, JUNCOl and SETSPI, some of which have been modified slightly. </p> <p> The models have been tested on the Drury Lane and the Skyway, Burlington, Sewage Treatment Plants, and have been found to agree very well with plant data. The former has a conventional activated sludge process, whilst the latter employs the extended aeration modification. </p> <p> An inter-active version has been developed, which requires the minimum knowledge of GEMCS for its use. This can be applied as a training and teaching tool for plant operators and students in the field. </p> / Thesis / Master of Engineering (MEngr)
2

Decantação acelerada: alternativa para o tratamento de vazão excedente de esgoto - estudo na ETE Martim de Sá (Caraguatatuba/SP). / Lamella sedimentation: alternative for treatment of overflow sewage - study in ETE Martim de Sá (Caraguatatuba/SP).

Gomes, Fernanda Cavalcante 12 April 2010 (has links)
Este estudo foi motivado pela necessidade de se tratar o excesso de vazão afluente às estações de tratamento de esgoto, que ocorre em dias de chuvas intensas. A hipótese central deste estudo é a de que a adoção de processo físico-químico para o tratamento de esgoto excedente diluído, pode ser vantajosa em relação ao aumento da capacidade com a ampliação dos sistemas exclusivamente biológicos. A pesquisa foi desenvolvida na ETE Martim de Sá da SABESP, localizada em Caraguatatuba/SP, onde o esgoto é tratado por lodos ativados em bateladas sequenciais. Estudou-se a variação da vazão de esgoto afluente na época de chuvas, bem como o funcionamento das bateladas. Além disso, foi avaliado o emprego da coagulação, floculação e sedimentação em decantador laminar para tratar o excesso de vazão com aplicação de sulfato de alumínio, cloreto férrico e polímero catiônico em uma estação piloto, após a realização de ensaios em escala de bancada em aparelho de Jar Test. O monitoramento da vazão afluente mostrou que em dias de chuvas e com ocorrência de desvios, a vazão máxima foi 220 L/s, ou seja, até 6 vezes maior que a vazão média de tempo seco. Para esta situação, o processo físico-químico pode tornar-se uma alternativa promissora, devido à sua capacidade de trabalho sob altas vazões em instalações de menor porte. Nos ensaios para se avaliar o tratamento físico-químico utilizou-se esgoto bruto pertencente a duas faixas de DBO: 50 e 100 mg/L e taxa de aplicação superficial no decantador de 76,82 m³ / m² / dia. A melhor dosagem de produto químico utilizada para tratar o esgoto bruto da faixa de DBO igual a 50 mg/L foi 40mg/L de cloreto férrico mais 0,5mg/L de polímero catiônico resultando em efluentes com DBO média de 26mg/L. Para o esgoto bruto da faixa de DBO igual a 100 mg/L a melhor dosagem foi a de 60mg/L de cloreto férrico, com DBO média dos efluentes igual a 44mg/L. Para esta faixa de trabalho é recomendável prever a aplicação de polímero. Por esta pesquisa concluiu-se que é possível atender aos limites legais de qualidade do esgoto tratado com o emprego do tratamento físico-químico, além disso produziu elementos importantes para subsidiar a avaliação econômica para a implantação desta tecnologia em paralelo ao sistema de lodo ativado nas situações de sobrecarga hidráulica. No entanto, a análise do fluxograma do funcionamento da estação com o processo de lodos ativado em bateladas, indicou que é possível efetuar o tratamento da vazão de 220 L/s pelo processo biológico. Assim, é recomendável a implantação do tratamento físico-químico somente se, após a realização do teste em escala real do funcionamento das bateladas com a vazão de 220 L/s, o tratamento biológico não atender aos padrões estabelecidos. / This study was motivated by the need to treat high wastewater influent exceeding in sewage treatment plants, which occurs on days of heavy rain. The central hypothesis of this study is that the physical-chemical process to treat dilute sewage overflow, it can be advantageous with respect to increased capacity and expansion of biological systems. The research was conducted in ETE Martim de Sá (SABESP), located in Caraguatatuba / SP, where the sewage is treated by sequencing batch reactor. It was studied the variation of the flow of wastewater during the rainy season, and the operation of the batch. Furthermore, it was evaluated the use of coagulation, flocculation and sedimentation in plate settler with application of aluminium sulfate, ferric chloride and cationic polymer in a pilot plant, after the testing of bench scale apparatus in Jar Test. Monitoring the inflow showed that on days of rainfall and bypass, the maximum flow was 220 L/s, up to 6 times the dry weather average flow. For this situation, the physico-chemical process may become a promising alternative, due to its ability to work under high flow rates in smaller facilities. In tests to evaluate the physical-chemical treatment was used two kinds of raw sewage: 50 and 100 mg/L BOD, overflow rate used in the plated settling tank was 76.82 m³/m² / day. The best dosage of chemical used to treat the raw sewage BOD of 50 mg/L was 40 mg/L ferric chloride plus 0.5 mg/L of cationic polymer, resulting in average effluent with BOD of 26 mg/L. For the raw sewage of the range BOD of 100 mg/L, 60 mg/L ferric chloride was the best dosage with an average BOD of effluent equal to 44 mg/L. For this range of work is recommended to provide for the application of polymer. This research concluded that it is possible to comply with the legal standard of treated sewage with physical-chemical treatment, also produced evidence that can help in the economic evaluation for the implementation of this technology in parallel with the activated sludge system in hydraulic overload situations. However, analysis of the flow diagram of operation of the station with the sequencing batch reactor, indicated that it is possible to make the treatment of flow of 220 L/s by the biological process. Therefore, is recommend the implementation of physical-chemical treatment only if after the test-scale operation of the batches with the flow rate of 220 L/s, the biological treatment doesn\'t meet the established standards.
3

Decantação acelerada: alternativa para o tratamento de vazão excedente de esgoto - estudo na ETE Martim de Sá (Caraguatatuba/SP). / Lamella sedimentation: alternative for treatment of overflow sewage - study in ETE Martim de Sá (Caraguatatuba/SP).

Fernanda Cavalcante Gomes 12 April 2010 (has links)
Este estudo foi motivado pela necessidade de se tratar o excesso de vazão afluente às estações de tratamento de esgoto, que ocorre em dias de chuvas intensas. A hipótese central deste estudo é a de que a adoção de processo físico-químico para o tratamento de esgoto excedente diluído, pode ser vantajosa em relação ao aumento da capacidade com a ampliação dos sistemas exclusivamente biológicos. A pesquisa foi desenvolvida na ETE Martim de Sá da SABESP, localizada em Caraguatatuba/SP, onde o esgoto é tratado por lodos ativados em bateladas sequenciais. Estudou-se a variação da vazão de esgoto afluente na época de chuvas, bem como o funcionamento das bateladas. Além disso, foi avaliado o emprego da coagulação, floculação e sedimentação em decantador laminar para tratar o excesso de vazão com aplicação de sulfato de alumínio, cloreto férrico e polímero catiônico em uma estação piloto, após a realização de ensaios em escala de bancada em aparelho de Jar Test. O monitoramento da vazão afluente mostrou que em dias de chuvas e com ocorrência de desvios, a vazão máxima foi 220 L/s, ou seja, até 6 vezes maior que a vazão média de tempo seco. Para esta situação, o processo físico-químico pode tornar-se uma alternativa promissora, devido à sua capacidade de trabalho sob altas vazões em instalações de menor porte. Nos ensaios para se avaliar o tratamento físico-químico utilizou-se esgoto bruto pertencente a duas faixas de DBO: 50 e 100 mg/L e taxa de aplicação superficial no decantador de 76,82 m³ / m² / dia. A melhor dosagem de produto químico utilizada para tratar o esgoto bruto da faixa de DBO igual a 50 mg/L foi 40mg/L de cloreto férrico mais 0,5mg/L de polímero catiônico resultando em efluentes com DBO média de 26mg/L. Para o esgoto bruto da faixa de DBO igual a 100 mg/L a melhor dosagem foi a de 60mg/L de cloreto férrico, com DBO média dos efluentes igual a 44mg/L. Para esta faixa de trabalho é recomendável prever a aplicação de polímero. Por esta pesquisa concluiu-se que é possível atender aos limites legais de qualidade do esgoto tratado com o emprego do tratamento físico-químico, além disso produziu elementos importantes para subsidiar a avaliação econômica para a implantação desta tecnologia em paralelo ao sistema de lodo ativado nas situações de sobrecarga hidráulica. No entanto, a análise do fluxograma do funcionamento da estação com o processo de lodos ativado em bateladas, indicou que é possível efetuar o tratamento da vazão de 220 L/s pelo processo biológico. Assim, é recomendável a implantação do tratamento físico-químico somente se, após a realização do teste em escala real do funcionamento das bateladas com a vazão de 220 L/s, o tratamento biológico não atender aos padrões estabelecidos. / This study was motivated by the need to treat high wastewater influent exceeding in sewage treatment plants, which occurs on days of heavy rain. The central hypothesis of this study is that the physical-chemical process to treat dilute sewage overflow, it can be advantageous with respect to increased capacity and expansion of biological systems. The research was conducted in ETE Martim de Sá (SABESP), located in Caraguatatuba / SP, where the sewage is treated by sequencing batch reactor. It was studied the variation of the flow of wastewater during the rainy season, and the operation of the batch. Furthermore, it was evaluated the use of coagulation, flocculation and sedimentation in plate settler with application of aluminium sulfate, ferric chloride and cationic polymer in a pilot plant, after the testing of bench scale apparatus in Jar Test. Monitoring the inflow showed that on days of rainfall and bypass, the maximum flow was 220 L/s, up to 6 times the dry weather average flow. For this situation, the physico-chemical process may become a promising alternative, due to its ability to work under high flow rates in smaller facilities. In tests to evaluate the physical-chemical treatment was used two kinds of raw sewage: 50 and 100 mg/L BOD, overflow rate used in the plated settling tank was 76.82 m³/m² / day. The best dosage of chemical used to treat the raw sewage BOD of 50 mg/L was 40 mg/L ferric chloride plus 0.5 mg/L of cationic polymer, resulting in average effluent with BOD of 26 mg/L. For the raw sewage of the range BOD of 100 mg/L, 60 mg/L ferric chloride was the best dosage with an average BOD of effluent equal to 44 mg/L. For this range of work is recommended to provide for the application of polymer. This research concluded that it is possible to comply with the legal standard of treated sewage with physical-chemical treatment, also produced evidence that can help in the economic evaluation for the implementation of this technology in parallel with the activated sludge system in hydraulic overload situations. However, analysis of the flow diagram of operation of the station with the sequencing batch reactor, indicated that it is possible to make the treatment of flow of 220 L/s by the biological process. Therefore, is recommend the implementation of physical-chemical treatment only if after the test-scale operation of the batches with the flow rate of 220 L/s, the biological treatment doesn\'t meet the established standards.
4

Kritisk sedimenteringshastighet / Critical sedimentation velocity

Mohlander, Max January 2023 (has links)
Mellansedimenteringsbassänger är inte sällan flaskhalsen för flödeskapaciteten vid reningsverk. För höga flöden kan leda till slamflykt, vilket påverkar efterkommande reningssteg negativt. Om en stor mängd slam från systemet försvinner kan detta även påverka det biologiska reningssteget negativt. Att förstå dynamiken av slamkvalitet och flödeskapaciteten är därmed viktigt både för att veta hur nya bassänger ska dimensioneras och för att bestämma belastningen för befintliga bassänger. Syftet med denna studie var att utvärdera flödeskapaciteten för mellansedimenteringen för det biologiska reningssteg C vid Kungsängsverket, Uppsala Vatten och Avfall AB:s största reningsverk. Syftet var också att studera hur temperaturen påverkade flödeskapaciteten. Genom att utföra sedimenteringstester med slam från Biosteg C vid olika koncentrationer och temperaturer kunde slammets kvalitet kvantifieras och användas för beräkningar och simuleringar för utvärdering av flödeskapaciteten. Sedimenteringstesterna visade på en tydlig skillnad i sedimenteringshastiget vid de olika temperaturerna. I Stokes lag användes olika värden på densiteten och viskositeten, vilka är parametrarna som förändras med temperaturen, för att undersöka en förväntad förändring i sedimenteringshastiget. Kvoten mellan 20 och 5° C var cirka 2 och kvoten mellan 10 och 5° C var cirka 1,2. Kvoterna mellan sedimenteringstesten varierade, men resultatet visade på en liknande trend som för Stokes lag. Bürger-Diehls och Takács sedimenteringsmodeller användes i den här rapporten med Takács sedimenteringsfunktion. Bürger-Diehlmodellen användes för att kalibrera parametrarna i Takács sedimenteringsfunktion, vilket gjordes genom att simulera sedimenteringstest och minimera felet mot den verkliga slamnivån vid sedimenteringstesten. Parametern 𝑣0 minskade med ökande temperatur vilket är en omvänd trend jämfört med litteratur. Parametern 𝑟h minskade med temperaturen vilket stämmer överens med litteratur. Flödeskapaciteten utvärderades vid konstant och dynamiskt flöde. För det konstanta flödet användes olika modeller, State Point-analys, Takács sedimenteringsmodell samt Bürger-Diehls sedimenteringsmodell med 10 och 30 lager. Alla modeller visade på ökande flödeskapacitet med ökande temperatur. Takács och Bürger-Diehl med 10 lager gav mindre noggranna resultat på grund av den låga mängden lager så för det dynamiska flödessimuleringarna användes bara Bürger-Diehlmodellen med 30 lager. Dessa simuleringar visade liknade resultat som för det konstanta flöden vid 6° C och 12° C. Vid 22° C visade däremot det dynamiska resultatet på en lägre kapacitet än för det konstanta flödet. Trots att sedimenteringstesten och de skattade modellparamterarna visade på en icke försumbar temperaturpåverkan ingår inte temperaturen i de använda sedimenteringsmodellerna. Detta kan leda till överskattning av flödeskapaciteten vintertid, exempelvis vid snösmältning. I framtiden bör därför detta tas hänsyn till vid dimensionering/modellering av mellansedimenteringsbassänger. / Secondary sedimentation tanks are usually the bottleneck of the flow capacity for wastewater treatment plants. High flows risk sludge escaping the system, which can negatively affect the following treatment steps. If a greater amount of the activated sludge escapes, the treatment efficiency could greatly decrease. Understanding the dynamic of sludge quality and flow capacity is detrimental to designing new secondary settling tanks and determining capacity of existing ones. The purpose of this study was to evaluate the flow capacity of the secondary settling tank for the biological treatment step C at Kungsängsverket, Uppsala Vatten och Avfall AB’s biggest wastewater treatment plant. The purpose was to study how different temperatures affected the flow capacity as well. By performing batch settling tests with sludge from the biological treatment step C, with different concentrations and temperatures, the sludge quality was quantified and could be used for calculations and simulations to evaluate the flow capacity. A clear distinction in the zone settling velocity could be observed between the different temperatures. Different values for the density and viscosity, correlated to the different temperatures used for the batch tests, were used in Stoke’s law to get an expected change of velocity. Between 20° and 5° C the quota was roughly 2 and between 10° and 5° C it was around 1,2. The quota for the batch tests differed randomly for the different concentrations, but the result indicated a similar trend as for Stokes law. The Bürger-Diehl and Takács sedimentation models were used for this study with the sedimentation function of Takács. The Bürger-Diehl model was used to calibrate the parameters in Takács function. This was done by simulating a batch test and minimizimg the sum of squared error compared to the actual sludge level from the batch test. The parameter 𝑣0 decreased in value with increasing temperature, which is a reversed trend seen from the literature. The parameter rh decreased with increasing temperature, which follows literature trends. The flow capacity was evaluated for a constant and dynamic flow. Constant flow was used with different models for comparison, which were, State point analysis, the Takács sedimentation model and the Bürger-Diehl sedimentation model with 10 and 30 layers. The result from all models indicated a higher flow capacity the higher the temperature. The flow capacity with Takács and Bürger-Diehl models with 10 layers gave a lower flow capacity than expected, which was because of the low resolution, therefore, the Bürger-Diehl model with 30 layers was used for the dynamic flow. The dynamic flow gave a similar result for 6° and 12° C, however, for 22° C the flow capacity was lower for the dynamic flow. Even though the batch tests and the estimated parameters showed a difference with temperature, it’s not included in any sedimentation model. This could lead to an overestimation of the flow capacity during wintertime, for example during snowmelt. Further research should be conducted to confirm these results and possibly be interpreted for future modelling of secondary sedimentation tanks.
5

Revitalizace malého vodního toku / The Revitalization of a Small Watercourse

Svědínková, Renáta January 2013 (has links)
My diploma thesis deals with the issue revitalization of a small stream. Assessment and design of revitalization is done on Kuřimka stream which flows through the cadastral territory of the Moravian Knínice - Chudčice - Kníničky. In the diploma thesis were designed several of revitalization measures: stabilization of longitudinal tilt with the use of stone steps in the bottom and wooden thresholds, sedimentation reservoir for capturing sediment and slope stabilization using willow fences and gabions. Proposal of revitalization measures does not deteriorate runoff conditions.

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