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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

Materiais de tubulações utilizadas em sistemas de coleta e transporte de esgotos sanitários: estudo de caso da área norte de São Paulo. / Pipes materials used in sanitary sewer systems: case study of the northern area of São Paulo.

Bevilacqua, Nelson 06 October 2006 (has links)
Este trabalho descreve os diversos materiais que podem ser utilizados nas tubulações de sistemas de esgotos sanitários, apresenta suas principais características, a hidráulica das tubulações, principais fabricantes, aspectos construtivos, operação e manutenção e comentam-se as normas técnicas referentes a esses materiais. Os dados apresentados foram obtidos através de pesquisa na área norte de São Paulo cujo sistema é operado pela Sabesp, consultando-se as unidades funcionais de projeto, apoio técnico, operação, manutenção e obras da Sabesp. Destaca-se a preferência pelo uso das tubulações de PVC para a implantação e manutenção das ligações prediais e redes coletoras devido às vantagens de sua aplicação, tais como: facilidade de transporte e manuseio, maior produtividade, menos problemas operacionais, praticidade e segurança. Para coletores de maiores diâmetros e interceptores há preferência pelos tubos de PRFV, PVC e PEAD e pelo sistema de tubo de concreto cravado. Na escolha do melhor material a ser utilizado, deve-se considerar além das características dos esgotos, a resistência, a disponibilidade, a facilidade de transporte, e custos desse material . Deve-se, também se levar em conta, o método aplicado na construção e as condições locais da obra. Como principais conclusões, destaca-se a viabilidade econômica da utilização do PVC em relação ao tubo cerâmico nas obras de redes e ligações, e a tendência da utilização de PRFV e PEAD na implantação de novos coletores com diâmetro de 300 a 500mm. Recomenda-se a utilização de juntas elásticas nas tubulações cerâmicas e a especificação do tipo de material precedida de estudos amplos de viabilidade que considerem a sua vida útil, praticidade de aplicação, custos, aspectos ambientais, operação, manutenção, segurança e rapidez na implantação da obra. / This dissertation describes the various materials used in sanitary sewer systems, presents their main characteristics, pipeline hydraulics and manufacturers. It also features construction, operational and maintenance aspects for the different materials as well as the technical regulations concerning these materials. Data were collected in the Northern area of São Paulo, whose sewer system is operated by Sabesp, through research in the following functional units: project, technical support, operations, maintenance and construction. This study highlights the operation area\'s preference for PVC pipes for building and maintenance of sewage connections and sewers because its advantages such as: ease of transportation and handling, greater productivity, less operational problems, practicity and safety. For large diameter trunk sewers and interceptors, FRP (Fiberglass reinforced plastic), PVC (Polyvinyl chloride) and PE (Polyethylene) pipes and Jacking Pipe system are usually the choice. In the selection of the best material, one should consider the wastewater characteristics and the material resistance, availability, ease of transportation and cost. The construction methods and local conditions should also be taken into account in this process. In conclusion, this study stresses the economical viability of PVC pipes over ceramical pipes in sewers and connections, the tendency to use FRP and PE in new 300 - to 500- mm- diameter trunk sewers and recommendation for the use of elastic joints with ceramical pipes. Lastly, the specification of the type of material to be used should be preceded by broad viability studies that consider its required life, practicity, cost, environmental aspects, operational and maintenance aspects and safety in the building process.
2

Sewer Overflows and the Vector Mosquito Proximity to Human West Nile Virus Infections

Bowers, Andrea Simone 01 January 2015 (has links)
DeKalb and Fulton Counties, which share the metropolitan Atlanta area, have seen an increase in West Nile infected vector mosquitoes; the increase is associated with close proximity to combined sewer overflow facilities. Despite completion of the remediation system in 2008, the mosquito population testing positive for West Nile virus has increased each year from 2010 through 2012. Guided by the Geographical Information System framework and using spatial analysis and regression analyses, this study described and quantified the relationship between sewer system overflows and amplification of vector mosquitoes; an additional goal was to investigate their proximity to human cases of West Nile VIrus (WNV) infections. Comparing the prominence of all WNV vectors revealed how different mosquito species occupy the area. The Culex species was not detected in adult surveillance in 2012; however, the infection rate of mosquito pools increased by 15% and the human infection more than doubled. The influence of sewer system overflows became pronounced when this study analysis also identified that a proportion of West Nile-virus positive mosquito pools was significantly higher in approximately 58% of trap sites within 1 km of sewer overflow events and 30% over 1 km distance from sewer overflow events. Thus, the research contributes to shared information both in support of previous findings and considering novel sources that contribute to the proliferation of WNV. This research can help reduce the rate of WNV infection and decrease the resources needed to protect the public.
3

Development of Analytical Probabilistic Models for the Estimation of Rainfall Derived Inflow/Infiltration Frequency

Mikalson, Daley Travis 14 December 2011 (has links)
Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.
4

Development of Analytical Probabilistic Models for the Estimation of Rainfall Derived Inflow/Infiltration Frequency

Mikalson, Daley Travis 14 December 2011 (has links)
Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.
5

Materiais de tubulações utilizadas em sistemas de coleta e transporte de esgotos sanitários: estudo de caso da área norte de São Paulo. / Pipes materials used in sanitary sewer systems: case study of the northern area of São Paulo.

Nelson Bevilacqua 06 October 2006 (has links)
Este trabalho descreve os diversos materiais que podem ser utilizados nas tubulações de sistemas de esgotos sanitários, apresenta suas principais características, a hidráulica das tubulações, principais fabricantes, aspectos construtivos, operação e manutenção e comentam-se as normas técnicas referentes a esses materiais. Os dados apresentados foram obtidos através de pesquisa na área norte de São Paulo cujo sistema é operado pela Sabesp, consultando-se as unidades funcionais de projeto, apoio técnico, operação, manutenção e obras da Sabesp. Destaca-se a preferência pelo uso das tubulações de PVC para a implantação e manutenção das ligações prediais e redes coletoras devido às vantagens de sua aplicação, tais como: facilidade de transporte e manuseio, maior produtividade, menos problemas operacionais, praticidade e segurança. Para coletores de maiores diâmetros e interceptores há preferência pelos tubos de PRFV, PVC e PEAD e pelo sistema de tubo de concreto cravado. Na escolha do melhor material a ser utilizado, deve-se considerar além das características dos esgotos, a resistência, a disponibilidade, a facilidade de transporte, e custos desse material . Deve-se, também se levar em conta, o método aplicado na construção e as condições locais da obra. Como principais conclusões, destaca-se a viabilidade econômica da utilização do PVC em relação ao tubo cerâmico nas obras de redes e ligações, e a tendência da utilização de PRFV e PEAD na implantação de novos coletores com diâmetro de 300 a 500mm. Recomenda-se a utilização de juntas elásticas nas tubulações cerâmicas e a especificação do tipo de material precedida de estudos amplos de viabilidade que considerem a sua vida útil, praticidade de aplicação, custos, aspectos ambientais, operação, manutenção, segurança e rapidez na implantação da obra. / This dissertation describes the various materials used in sanitary sewer systems, presents their main characteristics, pipeline hydraulics and manufacturers. It also features construction, operational and maintenance aspects for the different materials as well as the technical regulations concerning these materials. Data were collected in the Northern area of São Paulo, whose sewer system is operated by Sabesp, through research in the following functional units: project, technical support, operations, maintenance and construction. This study highlights the operation area\'s preference for PVC pipes for building and maintenance of sewage connections and sewers because its advantages such as: ease of transportation and handling, greater productivity, less operational problems, practicity and safety. For large diameter trunk sewers and interceptors, FRP (Fiberglass reinforced plastic), PVC (Polyvinyl chloride) and PE (Polyethylene) pipes and Jacking Pipe system are usually the choice. In the selection of the best material, one should consider the wastewater characteristics and the material resistance, availability, ease of transportation and cost. The construction methods and local conditions should also be taken into account in this process. In conclusion, this study stresses the economical viability of PVC pipes over ceramical pipes in sewers and connections, the tendency to use FRP and PE in new 300 - to 500- mm- diameter trunk sewers and recommendation for the use of elastic joints with ceramical pipes. Lastly, the specification of the type of material to be used should be preceded by broad viability studies that consider its required life, practicity, cost, environmental aspects, operational and maintenance aspects and safety in the building process.
6

Quantifying and Modeling Surface Inflow and Groundwater Infiltration into Sanitary Sewers in Southern Pinellas County, FL

Long, Megan E. 20 June 2017 (has links)
Following large rain events, excess flow in sanitary sewers from inflow and infiltration (I/I) cause sanitary sewer overflows (SSO), resulting in significant problems for Pinellas County and the Tampa Bay area. Stormwater enters the sanitary sewers as inflow from improper or illegal surface connections, and groundwater enters the system as infiltration through cracks in subsurface infrastructure. This pilot study was designed to develop methods to separate and quantify the components of I/I and to build a predictive model using flowmeter and rainfall data. To identify surface inflow, daily wastewater production and groundwater infiltration patterns were filtered from the flow data, leaving a residual signal of random variation and possible inflow. The groundwater infiltration (as base infiltration, BI) was calculated using the Stevens-Schutzbach method, and daily wastewater flow curves were generated from dry weather flow (DWF) data. Filtered DWF values were used to construct a range of expected residuals, encompassing 95% of the variability inherent in the system. Filtered wet weather flows were compared to this range, and values above the range were considered significant, indicating the presence of surface inflow. At all 3 flow meters in the pilot study site, no surface inflow was detected, and the I/I was attributed to groundwater infiltration (as BI). Flow data from 2 smaller sub-sewersheds within the greater sewershed allowed analysis of the spatial variability in BI and provided a method to focus in on the most problematic areas. In the sub-sewershed with the shallowest water table and most submerged sanitary sewer infrastructure, an average of 56% of the average daily flow consisted of groundwater, compared to 44% for the entire study site. Cross-correlation analysis suggests that rain impacts the water table for up to 9 days, with the highest impact 1 to 3 days after rain events, and the water table, in turn, impacts infiltration for up to 6 days. The highest correlation between rainfall and infiltration occurs 3 to 5 days after a rain event, which corroborates observations from Pinellas County that severe flows to the reclamation facility continue for 3 to 5 days after severe storms. These results were used to build a linear regression model to predict base infiltration (per mile of pipeline) during the wet season using the previous 7 days of daily rainfall depths. The model tended to under-predict infiltration response to large storm events with a R2 value of 0.52 and standard error of regression of 5.3. The results of the study show that inflow can be detected using simple time series analysis instead of traditional smoke and dye testing. In this study site, however, groundwater infiltration is the only significant source of I/I. Additionally, water table and sewer invert elevations serve as useful indicators of potential sites of groundwater infiltration. Infiltration can be modeled as a function of the previous 7 days of rainfall, however simple linear regression cannot fully capture the complexity of the system response.
7

Prioritizing Rehabilitation of Sanitary Sewers in Pinellas County, FL

Hillman, Jesse T. 20 June 2019 (has links)
Following large rain events, extraneous freshwater contributions known as inflow and infiltration (I/I) bypass the storm sewer and enter the sanitary sewer system. In areas with a high water table, like Pinellas County and the surrounding Tampa Bay area, a majority of the wastewater infrastructure is submerged year round exacerbating the rate of groundwater infiltration. This excess flow overloads the existing wastewater infrastructure leading to sanitary sewer overflows (SSOs). These SSOs result in serious problems for municipalities and utilities across the country. This study was performed in order to assist Pinellas County Utilities in rehabilitating their southern sewer system. To do this, 59 sub-basins across 8 sewer zones were monitored through Pinellas County’s Phase 1 Flow Monitoring Program accounting for over 150 miles of gravity pipe. For each sub-basin, a flow meter was utilized to measure the flow from May to October, 2017. This data was analyzed to separately quantify the amount of infiltration and inflow in each sub-basin, respectively. Once quantified, a Severity Index (SI) was developed in order to give each sub-basin a score from 1-100 as it relates to the condition of the gravity mains in the sub-basin. The SI was a function of locational features available with the use of a Geographic Information System (GIS), such as the distance to water bodies and the soil hydrologic group (SHG), as well as intrinsic pipe properties including the type of pipe material and the age of pipe. Once validated with additional flow monitoring data, the developed SI framework can serve as an additional tool utilized by Pinellas County Utilities to identify areas in need of sanitary sewer rehabilitation. Being that the model only requires easily attainable information, this approach is less time consuming and is inexpensive as compared to traditional flow monitoring efforts. The study also examined the required monetary investment by Pinellas County Utilities in order to abate the 17 sub-basins observed in the study with an infiltration rate greater than the marginal threshold put forth by the Environmental Protection Agency (EPA). The study indicated that gravity pipe rehabilitation does not make a significant impact on groundwater infiltration until at least 30% of the gravity pipes in the sub-basin are lined. This is due to the groundwater table submerging a majority of the wastewater infrastructure. Once this threshold is met, lining was observed to abate groundwater infiltration linearly. The results found that $4.4 million will be required to rehabilitate the affected sub-basins to a marginal rate of infiltration and reduce the flow to South Cross Bayou Water Reclamation Facility (SCBWRF) by an average of 0.72 mgd (million gallons per day). On an annual basis, this reduction in flow will result in approximately $650,000 in treatment costs savings.
8

Planejamento operacional para execução dos sistemas prediais hidráulicos, sanitários e de gás combustível / Planning for implementation of operating systems hydraulic building, fuel gas and sanitary

Matos, Adriano Oliveira 30 June 2011 (has links)
Made available in DSpace on 2016-06-02T20:09:14Z (GMT). No. of bitstreams: 1 3951.pdf: 4065471 bytes, checksum: 6bca7e3049841545a8e51fd8370f8cca (MD5) Previous issue date: 2011-06-30 / Financiadora de Estudos e Projetos / In an increasingly competitive civil construction market affected by the ever greater shortage of skilled construction labor, the correct calculation of work team size based on labor productivity data that are feasible and representative of each construction company is an important strategy for overcoming today s challenges. Construction work includes hydraulic and sanitary sewer systems and piped cooking gas installations for buildings, due to the fact that work team size is often calculated empirically. Thus, the objective of this work is to propose a method to calculate the size of teams for the execution of these systems, based on goals of labor productivity and operational planning for the execution of these services, by allocating the members of the teams to the jobs programmed within the timetable foreseen in the work schedule. The proposed method is divided into three main stages: (a) diagnosis of current labor productivity; (b) calculation of work team size and planning at operational level, involving programming of the activities of each work team over the period stipulated for the execution of the work; and (c) control of productivity according to the established goals. The method was applied at a construction site, specifically during the execution of the cold water supply systems and the sanitary sewer systems located in the wet environments of two multistorey residential towers. The method produced satisfactory results, improving labor productivity in the execution of the cold water supply systems by 20.1% and in that of the sanitary sewer systems by 27.7%. / Num mercado de construção civil cada vez mais competitivo e potencializado com o crescente aumento da escassez de mão de obra qualificada para a execução dos serviços, o correto dimensionamento das equipes de execução destes com base em dados de produtividade da mão de obra factíveis e representativos de cada empresa construtora torna-se uma estratégia importante na superação destes desafios impostos atualmente. Dentre os serviços de construção, merecem destaques aqueles relacionados aos sistemas prediais hidráulicos, sanitários e de gás combustível pelo fato de, muitas vezes, as equipes de trabalho serem dimensionadas de forma empírica. Assim, este trabalho tem como objetivo a proposição de um método para o planejamento operacional da execução destes serviços com base no estabelecimento de metas de produtividade da mão de obra e da programação das atividades das equipes dentro dos prazos previstos de acordo com o cronograma da obra. O método proposto é dividido em três etapas principais: (a) diagnóstico da produtividade da mão de obra vigente; (b) dimensionamento das equipes de execução e planejamento ao nível operacional contendo a programação das atividades de cada equipe ao longo do prazo estipulado para execução dos serviços e (c) controle da produtividade em função das metas estabelecidas. O método foi aplicado em um canteiro de obras, especificamente na execução dos ramais de água fria e na execução dos ramais de esgoto sanitário localizados nos ambientes molháveis de duas torres de edifício residencial de múltiplos pavimento. Os resultados obtidos com a aplicação do método nestes dois serviços foram satisfatórios, ocasionando uma melhoria da produtividade da mão de obra (RUP cumulativa) na execução destes serviços na ordem de 20,1% e 27,7%, respectivamente.
9

Avaliação da qualidade virológica do efluente doméstico tratado e disponibilizado para reúso na cidade de São Paulo. / Evaluation of virological quality of treated wastewater available for urban reuse in Sao Paulo city.

Garrafa, Patricia 25 May 2009 (has links)
O objetivo deste estudo foi avaliar a qualidade virológica da água de reúso produzida em uma das estações de tratamento de esgoto da cidade de São Paulo. Para tanto, foram coletadas concomitantemente 177 amostras de esgoto tratado (100L) e bruto (15L) e os vírus concentrados utilizando método Viradel-ultracentrifugação. Em seguida as amostras foram tratadas com Vertrel XF e os ácidos nucléicos extraídos para a detecção de adenovírus (HAdV), rotavírus (RV-A), norovírus e vírus da hepatite A (VHA). A detecção por PCR e/ou RT-PCR evidenciou RV-A (G1-G5), VHA e HAdV incluindo os da espécie F tanto no esgoto bruto quanto no tratado, no entanto norovírus não foram detectados em ambos os efluentes. A infectividade de RV-A e HAdV foi avaliada por cultivo celular e os rotavírus RV-A foram também quantificados por reação de imunoperoxidase direta. PCR em tempo real foi padronizada para quantificação de vírus não cultiváveis ou de difícil cultivo como os VHA. Com base nos resultados obtidos foi verificada a ocorrência e a distribuição anual de cada vírus nas águas de reúso. / The aim of the study was to evaluate the virological quality from one Sewage Treatment Plant in the state of São Paulo. From January/2005 to November/2006, 177 samples (15L) of raw sewage were collected at the entrance and another 177 (100L) at the end of treatment, twice a week. Viruses were concentrated by filtration through positively charged microporous filters, followed by ultracentrifugation. Virus concentrates were treated by using Vertrel-XF and the viral genomes extracted for detection of adenovirus (HAdV), rotavirus (RV-A), norovirus and hepatitis A virus (HAV). PCR and RT-PCR revealed RV-A (G1-G5), HAV and HAdV, including the enteric ones (species F) in sewage and treated wastewater samples. Norovirus was not detected in any samples. The infectivity of HAdV and RV-A was assayed by inoculating onto suitable cell line. Immunoperoxidase assay was used to calculate the rotavirus FFU/L in the samples. Real time-PCR was standardized for enumeration of non-cultivable virus. The occurrence and annual distribution of each virus in reuse water were analyzed.
10

O lixiviado dos aterros sanitários em estações de tratamento dos sistemas públicos de esgotos / The leachate from landfill in wastewater treatment systems public sewers

Bocchiglieri, Miriam Moreira 11 May 2010 (has links)
O presente trabalho discute o recebimento de lixiviado de aterros sanitários em estações de tratamento do sistema público de esgotos para tratamento conjunto. Descreve os processos de geração do lixiviado nos aterros e faz uma avaliação desse recebimento em quatro estações de tratamento em operação no Estado de São Paulo que empregam processos biológicos de tratamento por lodos ativados convencional e por batelada, lagoas de estabilização (anaeróbia seguida de facultativa) e lagoas aeradas. Também apresenta a variação da produção de lixiviado em aterros sanitários em função dos períodos de chuva e seca, estabelecidos pela precipitação observada no período avaliado. Conclui que o tratamento conjunto de lixiviado de aterro é uma alternativa a ser considerada no planejamento dos sistemas de resíduos sólidos e de esgotos sanitários. A adoção do tratamento conjunto traz benefícios a esses sistemas e à sociedade, pois pode representar economia de escala, atendimento às exigências legais e conformidade ambiental, promovendo melhores condições de saúde pública / This work discuss the receipt of sanitary landfill leachate by public wastewater treatment plants for joint treatment. It describes the processes theough which leachate is generated in landfills and assesses its receipt in four wastewater treatment plants in the state of São Paulo that employ biological processes such as conventional and batch activated sludge and stabilization ponds (anaerobic pond followed by facultative pond). Additionally, the work shows the variation in the production of leachate during the dry and rainy seasons, which were established based on the volume of rainfall during the period of study. The conclusion is that the joint treatment of landfill leachate by wastewater treatment plants with the appropriate technical and operational criteria is na alternative to be considered in the planning of solid waste and sanitary sewer systems and the society because it would result in economy of scale, compliance with legal and environmental legislation, and improvement of public health

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