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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.
501

Desempenho de reatores UASB expostos a choques de carga hidráulica e diluição de matéria orgânica devidos a eventos de chuva

Salazar Peláez, Mónica Liliana January 2007 (has links)
Os sistemas de esgotos urbanos são classificados em separador absoluto, separador parcial e unitário, conforme o grau de separação que existe no recolhimento dos esgotos sanitários e das águas de drenagem pluviais. Embora a diretriz das cidades brasileiras seja a adoção do sistema separador, na prática ocorre uma importante contribuição das águas de chuvas nas vazões afluentes às estações de tratamento de esgotos como produto das interconexões existentes, clandestinas ou não, entre as redes de esgotos sanitários e pluviais. Esta pesquisa investigou os impactos causados pelos choques de carga orgânica e hidráulica provocados pela contribuição das águas pluviais no desempenho de reatores UASB e seu tempo de recuperação depois de sofrer estes choques. Três reatores de acrílico de 17 litros foram construídos no Laboratório de Saneamento Ambiental do IPH. Os reatores trataram esgoto sintético simulando a concentração de DQO de esgotos domésticos a uma temperatura de 30 ± 2 °C. Um dos reatores serviu de controle enquanto os outros dois receberam choques de carga hidráulica (aumento de vazão) e diluição de matéria orgânica, simultaneamente. A operação dos reatores foi dividida em três fases: 1°) aclimatação, 2°) choques individuais de carga hidráulica e diluição de matéria orgânica 3°) simulação de uma temporada de chuva. Os choques tiveram um efeito deletério na qualidade do efluente, ocasionando quedas na eficiência de remoção de DQO total de até quase 600% e de 200% na eficiência de remoção de DQO dissolvida nos choques mais severos. Também constatou-se perda de parte da biomassa presente nos reatores devido ao aumento excessivo na velocidade ascensional do fluxo. Esta perda tornou-se menor com o tempo devido à pressão de seleção exercida pelos sucessivos choques. O pH dentro dos reatores manteve-se sempre perto da faixa neutra, porém apresentou-se um consumo de alcalinidade que se prolongou por até três vezes o tempo de detenção hidráulica após o início dos choques, devido provavelmente ao aumento na concentração de ácidos graxos voláteis no efluente. A produção de biogás também diminuiu como conseqüência da diluição da carga orgânica afluente. Os efeitos e o tempo de recuperação após os choques dependeram da sua duração e magnitude, sendo que os choques mais severos (menor concentração de matéria orgânica afluente e TDH) causaram maior deterioração na qualidade do efluente e requereram maior tempo de recuperação.Já no que diz respeito às características físico-químicas e biológicas do lodo, verificou-se que os choques causaram diminuição no tamanho médio dos grânulos do lodo e na sua velocidade de sedimentação, provavelmente devido ao aumento das forças abrasivas v provocado pelo incremento na velocidade ascensional do fluxo. De igual modo, a atividade metanogênica específica também apresentou quedas devidas, provavelmente, à diluição da carga orgânica afluente e à diminuição do tamanho das partículas do lodo. / Sewerage systems are classified as separate, partially separated, or combined, according to the degree of separation that exists in the collection of municipal wastewater and stormwater runoff. Although the official policy of brazilian cities is for adoption of the separate system, the actual scenario shows that there are significant contributions of stormwater to the flows that are transported to the wastewater treatment plants, partly because of the inappropriate interconnections that exist between the systems. This research investigated the impacts that organic and hydraulic shock loads brought by stormwater contributions have on the efficiency of UASB reactors, as well as the recovery time after the ending of the shocks. Three 17-liters acrylic reactors were built in the Environmental Technology Laboratory at IPH. The reactors were fed with synthetic wastewater prepared to resemble the organic content of wastewater. All reactors were operated at a temperature of 30 ± 2ºC. One of the reactors was used as control while the other two received hydraulic shocks with organic matter dilution, simultaneously. Reactor’s operation was divided in three phases: 1º) star-up, 2º) single organic and hydraulic shocks, and 3º) rain season simulation, with multiple shocks.Shocks have a deleterious effect on the reactor effluent quality. In the most severe cases, drops in removal efficiencies reached up to 200% and 600% for dissolved and total DQO, respectively. Reactor biomass washout occurred due to the increasing upflow velocity. This loss was dampened by the selective pressure exerted by successive shocks. pH in the reactors remained in the neutral range, although alkalinity was consumed for as long as three detention times, probably due to an increase in the concentration of volatile fatty acids in the liquid. Dilution also caused a decrease in biogas production. Recovery time depended on the duration and intensity of the shock, with more severe shocks demanding more time for recovery. The impacts of the shocks on the treatment efficiency depended on duration, organic dilution rate and flowrate increase. Longer shocks, with higher flowrates and dilution rate resulted in the worst conditions for the reactor. Shocks loads caused a decrease in the mean size of the sludge granule, as well as in their sedimentation velocities, probably because of an increase in the abrasive forces acting on the granules brought by the upflow velocity. The specific methanogenic activity also decreased with higher dilution and smaller sized sludge granules.
502

Análise do manejo das águas pluviais no município de São Carlos : estudo da bacia do córrego Santa Maria do Leme

Pelissari, Mario Henrique Dias 31 March 2016 (has links)
Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-10-06T14:33:11Z No. of bitstreams: 1 DissMHDP.pdf: 33010393 bytes, checksum: b6d6de78607499f0d4066cfa4b021b63 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:49:59Z (GMT) No. of bitstreams: 1 DissMHDP.pdf: 33010393 bytes, checksum: b6d6de78607499f0d4066cfa4b021b63 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:50:05Z (GMT) No. of bitstreams: 1 DissMHDP.pdf: 33010393 bytes, checksum: b6d6de78607499f0d4066cfa4b021b63 (MD5) / Made available in DSpace on 2016-10-20T13:50:11Z (GMT). No. of bitstreams: 1 DissMHDP.pdf: 33010393 bytes, checksum: b6d6de78607499f0d4066cfa4b021b63 (MD5) Previous issue date: 2016-03-31 / Não recebi financiamento / A major challenge of Brazilian municipalities is to harmonize urban growth with the provision of public service. São Carlos, a municipality in the State of São Paulo also tries to solve this issue. The lack of urban planning coupled with the absence of occupation control measures promotes the soil sealing, which is responsible for the flooding in the valley bottoms. Considering this scenario, the object of study of this dissertation is the creek watershed Santa Maria do Leme. This watershed, even undeveloped, suffers with the occurrence of flooding in the region of its mouth. The aim of this study was to identify the main factors that contribute directly or indirectly with the flooding in the watershed. To this end, the following analyzes were performed: chronological analysis of the evolution of the runoff coefficient and the design flow by Rational Method ; analysis of velocity and capacity of flow in urban crossings; and analysis of the main legal instruments and the direct actions of the municipality in the management of urban drainage. The results indicate a problematic assessment of the region. Were analysed six crossings and only two have enough transport capacity for the flow of current project, and the municipal Master Plan indicates the region free of this basin as a potential area of urban expansion, a fact that may further aggravate the problems. / Um dos grandes desafios dos municípios brasileiros é harmonizar o crescimento urbano com a oferta de serviços públicos. São Carlos, um município do interior Paulista, também busca resolver esta questão. A falta de planejamento urbano aliada a ausência de medidas de controle de ocupação favorecem a impermeabilização do solo, que por sua vez é a responsável pelos alagamentos nos fundos de vale. Considerando esse cenário, apresenta-se como objeto desse estudo a bacia do córrego Santa Maria do Leme, uma bacia que mesmo pouco urbanizada, sofre com a ocorrência de alagamentos na região de sua foz. O objetivo desse trabalho foi identificar os principais fatores que contribuem para a ocorrência dos alagamentos na bacia. Para tanto, foram realizadas as seguintes análises: Análise cronológica da evolução do coeficiente de escoamento superficial e da vazão de projeto pelo Método Racional; Análise da velocidade e da capacidade de escoamento das travessias urbanas; e Análise dos principais instrumentos legais e das ações diretas da municipalidade na gestão da drenagem urbana. Os resultados obtidos apontam um diagnóstico problemático da região, pois das seis travessias analisadas, somente duas possuem capacidade de escoamento suficiente para a vazão de projeto atual, e o Plano Diretor municipal indica a região livre dessa bacia como área de potencial expansão urbana, fato que pode agravar ainda mais os problemas.
503

Desempenho de reatores UASB expostos a choques de carga hidráulica e diluição de matéria orgânica devidos a eventos de chuva

Salazar Peláez, Mónica Liliana January 2007 (has links)
Os sistemas de esgotos urbanos são classificados em separador absoluto, separador parcial e unitário, conforme o grau de separação que existe no recolhimento dos esgotos sanitários e das águas de drenagem pluviais. Embora a diretriz das cidades brasileiras seja a adoção do sistema separador, na prática ocorre uma importante contribuição das águas de chuvas nas vazões afluentes às estações de tratamento de esgotos como produto das interconexões existentes, clandestinas ou não, entre as redes de esgotos sanitários e pluviais. Esta pesquisa investigou os impactos causados pelos choques de carga orgânica e hidráulica provocados pela contribuição das águas pluviais no desempenho de reatores UASB e seu tempo de recuperação depois de sofrer estes choques. Três reatores de acrílico de 17 litros foram construídos no Laboratório de Saneamento Ambiental do IPH. Os reatores trataram esgoto sintético simulando a concentração de DQO de esgotos domésticos a uma temperatura de 30 ± 2 °C. Um dos reatores serviu de controle enquanto os outros dois receberam choques de carga hidráulica (aumento de vazão) e diluição de matéria orgânica, simultaneamente. A operação dos reatores foi dividida em três fases: 1°) aclimatação, 2°) choques individuais de carga hidráulica e diluição de matéria orgânica 3°) simulação de uma temporada de chuva. Os choques tiveram um efeito deletério na qualidade do efluente, ocasionando quedas na eficiência de remoção de DQO total de até quase 600% e de 200% na eficiência de remoção de DQO dissolvida nos choques mais severos. Também constatou-se perda de parte da biomassa presente nos reatores devido ao aumento excessivo na velocidade ascensional do fluxo. Esta perda tornou-se menor com o tempo devido à pressão de seleção exercida pelos sucessivos choques. O pH dentro dos reatores manteve-se sempre perto da faixa neutra, porém apresentou-se um consumo de alcalinidade que se prolongou por até três vezes o tempo de detenção hidráulica após o início dos choques, devido provavelmente ao aumento na concentração de ácidos graxos voláteis no efluente. A produção de biogás também diminuiu como conseqüência da diluição da carga orgânica afluente. Os efeitos e o tempo de recuperação após os choques dependeram da sua duração e magnitude, sendo que os choques mais severos (menor concentração de matéria orgânica afluente e TDH) causaram maior deterioração na qualidade do efluente e requereram maior tempo de recuperação.Já no que diz respeito às características físico-químicas e biológicas do lodo, verificou-se que os choques causaram diminuição no tamanho médio dos grânulos do lodo e na sua velocidade de sedimentação, provavelmente devido ao aumento das forças abrasivas v provocado pelo incremento na velocidade ascensional do fluxo. De igual modo, a atividade metanogênica específica também apresentou quedas devidas, provavelmente, à diluição da carga orgânica afluente e à diminuição do tamanho das partículas do lodo. / Sewerage systems are classified as separate, partially separated, or combined, according to the degree of separation that exists in the collection of municipal wastewater and stormwater runoff. Although the official policy of brazilian cities is for adoption of the separate system, the actual scenario shows that there are significant contributions of stormwater to the flows that are transported to the wastewater treatment plants, partly because of the inappropriate interconnections that exist between the systems. This research investigated the impacts that organic and hydraulic shock loads brought by stormwater contributions have on the efficiency of UASB reactors, as well as the recovery time after the ending of the shocks. Three 17-liters acrylic reactors were built in the Environmental Technology Laboratory at IPH. The reactors were fed with synthetic wastewater prepared to resemble the organic content of wastewater. All reactors were operated at a temperature of 30 ± 2ºC. One of the reactors was used as control while the other two received hydraulic shocks with organic matter dilution, simultaneously. Reactor’s operation was divided in three phases: 1º) star-up, 2º) single organic and hydraulic shocks, and 3º) rain season simulation, with multiple shocks.Shocks have a deleterious effect on the reactor effluent quality. In the most severe cases, drops in removal efficiencies reached up to 200% and 600% for dissolved and total DQO, respectively. Reactor biomass washout occurred due to the increasing upflow velocity. This loss was dampened by the selective pressure exerted by successive shocks. pH in the reactors remained in the neutral range, although alkalinity was consumed for as long as three detention times, probably due to an increase in the concentration of volatile fatty acids in the liquid. Dilution also caused a decrease in biogas production. Recovery time depended on the duration and intensity of the shock, with more severe shocks demanding more time for recovery. The impacts of the shocks on the treatment efficiency depended on duration, organic dilution rate and flowrate increase. Longer shocks, with higher flowrates and dilution rate resulted in the worst conditions for the reactor. Shocks loads caused a decrease in the mean size of the sludge granule, as well as in their sedimentation velocities, probably because of an increase in the abrasive forces acting on the granules brought by the upflow velocity. The specific methanogenic activity also decreased with higher dilution and smaller sized sludge granules.
504

Eventos pluviais extremos e risco de inundações na cidade de Aracaju/SE

Brazil, João Luiz Santana 31 May 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The disorderly growth of cities has caused a continuous process of environmental degradation in urban centers, providing a setting for risks caused by climatic factors. It is in this context that, from the 70s, the city of Aracaju has grown considerably. The process of occupation of environmentally fragile areas, for socially vulnerable populations is critical to the formation of areas of risk, exposed to more intense rainfall events. This research aims to analyze the extreme rainfall events in the areas of risk to flooding from the urban development of the city of Aracaju / SE. To achieve the proposed objectives was made using different procedures, emphasizing the theoretical review, covering theory and urban climate, cartographic survey and field work to show and record the areas at risk of flooding. The methodology allowed the crossing of social and environmental variables to identify the level of risk to flooding. The results achieved in this research led to the acceptance of the rain is the main cause of the risk of formation to flooding in Aracaju / SE, but that comes from overlapping with the pace of urbanization in the city. In addition, the study also demonstrated that an adequate sanitation service, if the urban drainage service contributes directly to improving the health of the population. The risk to flooding can be analyzed and verified in comparison of existing typological patterns in Aracaju in 2004, compared to the current typological standards in 2014. The city is another and their relationships as well. Thus, the extreme rainfall events that occur in the city of Aracaju occur in the autumn and winter period, between the months of March to July, and cause the exposure condition of the risk to the resident, varies according to their socioeconomic standard population / O crescimento desordenado das cidades tem causado um contínuo processo de degradação ambiental nos centros urbanos, propiciando um cenário para riscos causados pelos fatores climáticos. É nesse contexto que, a partir da década de 70, a cidade de Aracaju cresceu consideravelmente. O processo de ocupação de áreas ambientalmente frágeis, por populações socialmente vulneráveis, é decisivo para a formação de espaços de riscos, mais expostos a eventos pluviais intensos. Esta pesquisa tem como objetivo analisar os eventos pluviais extremos nas áreas de risco à inundações a partir do desenvolvimento urbano da cidade de Aracaju/SE. Para o alcance dos objetivos propostos fez-se uso de procedimentos distintos, priorizando a revisão teórica, levantamento cartográfico e trabalho em campo para evidenciar e registrar as áreas de risco de inundações. A metodologia utilizada permitiu o cruzamento das variáveis socioambientais para identificação do nível de risco a inundações. Os resultados alcançados nesta pesquisa conduziram para a aceitação de que a chuva é a principal causa da formação de risco a inundações em Aracaju/SE, mas que advém das imbricações com os ritmos da urbanização na cidade. Além disso, o estudo demonstrou ainda que um serviço de saneamento adequado, no caso o serviço de drenagem urbana contribui diretamente para a melhoria da qualidade de vida da população. O risco a inundações pode ser analisado e constatado em comparativos dos padrões tipológicos preexistentes em Aracaju em 2004, frente aos atuais padrões tipológicos em 2014. A cidade é outra e suas relações também. Assim, os eventos pluviais extremos que registrados na cidade de Aracaju estão concentradas no período de outono e inverno, entre os meses de março a julho, e ocasionam a condição de exposição a riscos para a população residente, variável conforme seu padrão socioeconômico. Conclui-se, portanto, que para que as políticas públicas sejam eficazes, é fundamental que as autoridades públicas considerem as peculiaridades e particularidades naturais da cidade de Aracaju, remanejando as pessoas das áreas propensas às inundações, além de garantir investimentos na educação ambiental, visando diminuir a quantidade de despejo de lixo nos rios e buscar soluções de engenharia mais adequadas.
505

Metodologia para apoio à decisão na gestão das águas pluviais urbanas combinando métodos multicriterial e multidecisor

ARAÚJO, Danniel Cláudio de 19 April 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-27T14:52:11Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_Danniel_Araujo_Versão_Final_CORRIGIDA_19_12.pdf: 7286311 bytes, checksum: 340b8aee0cbc2095c53a285cd4de9012 (MD5) / Made available in DSpace on 2017-04-27T14:52:11Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_Danniel_Araujo_Versão_Final_CORRIGIDA_19_12.pdf: 7286311 bytes, checksum: 340b8aee0cbc2095c53a285cd4de9012 (MD5) Previous issue date: 2016-04-19 / CAPES / CNPQ / A urbanização altera significativamente os processos de escoamento natural da bacia hidrográfica, com aumento do volume das águas pluviais escoadas superficialmente, incremento das vazões de pico dos corpos hídricos, degradação da qualidade da água e geração de sedimentos. Neste contexto, a gestão das águas pluviais surge como uma alternativa para resolução de conflitos relativos a quantidade/qualidade destes recursos (conflitos de primeira ordem). No entanto, devido essa gestão exigir a participação de vários setores da sociedade, pode vir a gerar conflitos devido à falta/inadequação do arranjo institucional responsável por essa gestão (conflitos de segunda ordem). Diante desta problemática, é possível observar a importância exercida pelo contexto legal, institucional e socioeconômico e da visão global do sistema envolvido para a tomada de decisão. Esta tese, portanto, concebe uma metodologia para apoio à decisão na gestão das águas pluviais urbanas combinando métodos multicriterial e multidecisor, a qual se constitui em quatro etapas: (i) investigação dos parâmetros iniciais; (ii) avaliação dos métodos multicriteriais AHP (Analytic Hierarchy Process) e o PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations) (iv) avaliação do método multidecisor COPELAND simulando a gestão participativa com a implantação do comitê de rio urbano; (iv) obtenção do subconjunto de alternativas potenciais como resultado final da aplicação do modelo. A metodologia foi aplicada na sub-bacia do canal da Sanbra, que é um dos contribuintes do rio Jiquiá situado em Recife-PE. Nesse sentido, foi avaliado a seleção da melhor técnica compensatória para este riacho considerando aspectos ambientais, sociais, econômicos e hidráulicos. Os resultados obtidos demonstraram que a metodologia desenvolvida pode apoiar a tomada de decisão na gestão das águas pluviais, de modo a consubstanciar resultados mais satisfatórios dessa realidade, seja através do entendimento e ampliação da gestão participativa, quanto no aperfeiçoamento técnico dos tomadores de decisão. / Urbanization significantly alters the processes of natural drainage of the river basin, increasing the volume of rainwater drained superficially, increasing peak flows of water bodies, degradation of water quality and sediment generation. In this context, rainwater management appears as an alternative for resolving conflicts regarding the quantity / quality of these resources (first order conflicts). However, because this management requires the participation of several sectors of society, it can generate conflicts due to the lack / inadequacy of the institutional arrangement responsible for this management (second order conflicts). Faced with this problem, it is possible to observe the importance exerted by the legal, institutional and socioeconomic context and the global vision of the system involved for the decision making.This thesis, therefore, devises a methodology for decision support in urban stormwater management combining multicriterial and multidecisor methods, which consists of four steps: (i) investigation of the initial parameters; (Ii) evaluation of the multi-criteria methods AHP (Analytic Hierarchy Process) and PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations) (iv) evaluation of the COPELAND multidecisor method simulating participatory management with the implementation of the urban river committee; (Iv) obtaining the subset of potential alternatives as a final result of the application of the model. The methodology was applied in the sub-basin of the Sanbra channel, which is one of the contributors of the Jiquiá river situated in Recife-PE. In this sense, it was evaluated the selection of the best compensatory technique for this stream considering environmental, social, economic and hydraulic aspects. The obtained results demonstrated that the developed methodology can support the decision making in rainwater management, in order to substantiate more satisfactory results of this reality, be it through the understanding and expansion of the participatory management, as well as in the technical improvement of the decision makers.
506

Biorretenção: tecnologia ambiental urbana para manejo das águas de chuva / Bioretention urban environmental technology for stormwater management

Newton Celio Becker de Moura 10 March 2014 (has links)
Em caráter experimental, a tese examina o desempenho de sistemas de biorretenção na mitigação da poluição difusa ocasionada pelas águas de chuva. A avaliação dessa tecnologia ambiental urbana partiu da construção de um modelo de manejo dos escoamentos pluviais, utilizando uma matriz orgânica composta por vegetação, solo e agregados para retenção e tratamento inicial localizados. O protótipo, em escala 1:1, implementado na Cidade Universitária Armando Salles de Oliveira (CUASO-USP), São Paulo, SP, é composto por dois canteiros isolados entre si, que recebem as vazões através da sarjeta na via adjacente. Com preenchimentos iguais, os canteiros receberam coberturas vegetais distintas: gramado (G), com uma única espécie de gramínia, e jardim (J), com forrações, herbáceas e arbustos diversos, predominantemente nativos. O experimento foi monitorado por um ano, entre março de 2012 e março de 2013, quando foram coletados os dados referentes ao seu funcionamento e eficiência em sete eventos chuvosos paulistanos. A compilação dessas informações permitiu a análise comparativa da qualidade da água dos escoamentos antes e depois da passagem pelos canteiros. Com recursos da FUNDEP, FCTH e LabVERDE, a pesquisa interdepartamental e interdisciplinar, desenvolvida numa cooperação entre a FAU-USP e a Escola Politécnica-USP, busca oferecer respostas às hipóteses com que trabalha a Arquitetura da Paisagem ao propor soluções naturalizadas de manejo dos escoamentos pluviais em complementação às técnicas convencionais atualmente empregadas nas cidades brasileiras, tomando a cidade de São Paulo como cenário. Como efeito do processo histórico de canalização do seu patrimônio hídrico, ocupação das áreas de várzea e impermeabilização, a população paulistana e da RMSP tem sofrido com enchentes que se agravam com o crescimento urbano e com a intensificação das chuvas. As soluções imediatistas para essa situação crítica seguem a práxis das obras convencionais de engenharia, que segregam a drenagem urbana dos processos ecológicos e hidrológicos e não contribuem para melhoria da qualidade ambiental dos escoamentos antes de destiná-los aos corpos hídricos superficiais, o que agrava o quadro generalizado de poluição dos rios e córregos urbanos. Os resultados do experimento prático atestam o desempenho da biorretenção na mitigação da poluição difusa, com reduções médias das cargas poluidoras acumuladas de 89,94% para o gramado e 95,49% para o jardim, que foi comprovadamente mais eficiente. Aliados ao estudo de tipologias paisagísticas já utilizadas com sucesso em outras cidades do mundo, esses resultados poderão corroborar o processo de transição na infraestrutura de São Paulo, respaldando tecnicamente e cientificamente as soluções investigadas de manejo das águas de chuva através da biorretenção no tratamento dos espaços abertos e na conformação de uma Infraestrutura Verde na cidade. / This thesis experimentally assesses the performance of bioretention systems in mitigating nonpoint-source pollution caused by runoff. A 1:1 scale experiment of a stormwater management facility was built in USP Campus based in São Paulo, SP. This prototype has been evaluated for one year, since March 2012, over its technical efficiency to improve water quality by analyzing runoff samples collected in its inlet and outlet. Combining landscape architecture and hydraulic engineering knowledge, this experiment consists of two independent vegetated plots connected to the gutter through a concrete channel, which drives the runoff into the facility from the avenue next to it. Each plot has its own spillway, where samples were collected for laboratory analysis under 22 water quality parameters and thus compared to gutter runoff. Regarding construction techniques, it was decided to apply simplified solutions without unnecessary expenses, but that ensured feasibility, solidity and isolation to the plots from the ground on all faces. As for filling the model, it was chosen to use the same material for both facilities, laid out from bottom to surface: 60cm of broken rocks, 15cm of gravel, coconut geotextile fabric, 5cm of coarse sand and, finally, 45 to 75cm of planting substrate with side slopes and covered with mulch. Regarding vegetation cover, two sets of plants have been used in the bioretention cells as a research strategy to compare the efficiency among different models in stormwater management, considering other issues in addition to improving the environmental quality of water, such as maintenance, adaptation and development of species and visual interest. Thus, the experiment plots were filled with the same substrate but with different vegetable toppings, according to the following configuration: mixed garden (M) - ground covers with predominance of native shrubs and herbaceous vegetation, and lawn (L) - covered only with emerald grass carpet (Zoysia japonica), which has been extensively used for lawns all over the country. This experimental model has provided scientific answers that attest the effectiveness of techniques using vegetated surfaces to retain and treat stormwater. Its results have attested the performance of bioretention for diffuse pollution mitigation, with average reductions of accumulated pollutant loads of 89.94% in the lawn (L) and 95.49% in the mixed garden (M), which wasproven to be more efficient. This research developed by USP Faculty of Architecture and Urbanism in partnership with Polythecnic School, does not aim to threat conventional methods of urban drainage in local cities, but to join them in the efforts of reaching solutions and technical knowledge that are suitable for urban ecosystems and harmless to environment and landscape.
507

Colonisation végétale des basins d’infiltration et de rétention : caractérisation de la flore et évolution des caractéristiques physico-chimiques de l’horizon de surface végétalisé / Vegetation of stormwater basins : flora inventory and physico-chemical characterization of vegetated surface

Saulais, Muriel 15 November 2011 (has links)
Les bassins de gestion des eaux pluviales, dont l’horizon de surface est parfois fortement contaminé, peuvent être naturellement ou volontairement colonisés par la végétation. L’objectif de ce travail est de mieux comprendre le rôle de la végétation dans le contrôle de la mobilité des métaux lourds comme le Zinc, le Cuivre et le Cadmium. Le premier volet de ces travaux, consacré à la caractérisation de la végétation se développant dans ces bassins, a montré que ces ouvrages abritaient une flore diversifiée, allant d’une végétation rudérale éparse à une végétation dense caractéristique de zones humides. Ensuite, une analyse physico-chimique multiparamétrique d’échantillons prélévés à la surface de bassins colonisés par des espèces végétales dominantes a été réalisée. Nous avons montré que les carbonates et la matière organique contrôlaient particulièrement la mobilité du Cu, Cd et Zn dans ces milieux. Les paramètres les plus variables temporellement et spatialement, sont essentiellement liés au cycle de la matière organique (nitrates, fraction métallique lié à la matière organique) mais également à l’apport de particules anthropiques (texture, métaux). Lorsque la plante est à son maximum de croissance, la mobilité potentielle des métaux est la plus élevée alors que la phase de sénescence de la plante semble conduire à un meilleur piégeage de ces contaminants. Cette thèse invite à considérer la végétation comme un agent de transformation de l’horizon de surface et à intégrer cette composante dans les futurs travaux sur la contamination des ouvrages d’assainissement urbain. / Urban stormwater basins surfaces can be highly contaminated and can be spontaneously or intentionaly vegetated. The aim of this work is to better characterize the role of the vegetation on heavy metal (Zn, Cd, Cu) mobility. Firstly, vegetation inventory has pointed out the high species diversity in these devices (from ruderal vegetation to wetland plants). Then, a physico-chemical characterization of surface samples vegetated by dominant species has been carried out. We have shown that carbonates and organic matter play a major role in the control of heavy metal mobility. The parameters which are the most spatially and temporally variable are essentially related to organic matter cycle (nitrate, heavy metal fraction bound to organic matter), and to the introduction of stormwater suspended matter (heavy metals, texture). At the maximum of plant growth phase, heavy metal mobility is enhanced and the period of plant death leads to a better heavy metal retention in the basin surface. This thesis invites us to consider plants as agents of surface stormwater basin transformation and to include plants in future research work.
508

Traitement et analyse de séries chronologiques continues de turbidité pour la formulation et le test de modèles des rejets urbains par temps de pluie / Treatment and analysis of continuous turbidities series for the test of urban stormwater quality models

Métadier, Marjolaine 14 February 2011 (has links)
Des approches parcimonieuses sont aujourd'hui développées pour la modélisation de la qualité des rejets urbains par temps de pluie, e adéquation avec la quantité de données disponibles. De plus, l'analyse des incertitudes apparaît comme un outil incontournable pour le test des modèles. Parallèlement, le développement des techniques de mesure en continu en réseau, spectrométrie et turbidité, permet l'obtention de données continues de flux de matières en suspension et de demande chimique en oxygène en grand nombre, apportant une information riche. Ce travail constitue une des premières études en hydrologie urbaine basée sur l'exploitation d'une grande base de données acquises par la mesure de la turbidité. Des mesures sur la période 2004-2008 ont été exploitées sur deux sites. Après traitement et validation, 263 et 239 événements pluvieux ont été retenus. L'analyse des données a permis la formulation d'hypothèses sur la génération des flux pour la proposition de modèles adaptés. Le test de l'approche multi-régression a confirmé la nécessité de construire des modèles locaux, basés sur une analyse approfondie des données. Les meilleurs modèles obtenus sont ceux pour la masse événementielle qui parviennent à reproduire en tendance la variabilité des observations. La méthode bayésienne a été utilisée pour le test d'un modèle d'Accumulation-Erosion-Transfert simple à l'échelle du bassin versant. Les premiers résultats mettent e défaut la structure du modèle testé. Cependant ces premiers tests ont démontré l'efficacité de la procédure d'analyse bayésienne, dont l'application du principe d'apprentissage permet d'améliorer de manière significative les structures des modèles. / More and more urban water managers are tackling the issue of water quality modelling. Current research works focus on parsimonious modelling approaches that match the amount of data available for calibration. Moreover uncertainties analysis now appears as an integrated step and a powerful tool in models testing. In parallel, development of in sewer continuous measurements based on spectrometry and turbidimetry techniques, provides large data base of continuous total suspended solids and chemical oxygen demand concentrations, providing much information on fluxes dynamics. This research work is one of the first studies in urban hydrology based on a large turbidity data base. Data from two sites have been treated and validated, with measurements over the period 2004-2008. 263 and 239 stormwater events were selected for the modelling work for the two sites. Data analysis provided insights for making assumptions on the pollutant fluxes generation and proposing adapted models. Test of multi-regression approach that it is necessary to build local approaches based on detailed data analysis. Best models were obtained for event mass, data variability could be reproduced in trend. Formal Bayesian approach was used for testing a simple global Accumulation-Erosion-Transfer model for Chassieu. First results evidenced the difficulties of the model to reproduce the dynamics variability. This may be due to the simple structure. However these first tests have demonstrated the efficiency of the Bayesian analysis procedure. ln particular, the application of the learning principle showed that model structure can be significantly and efficiently improved.
509

Amélioration des connaissances sur le colmatage des systèmes d’infiltration d’eaux pluviales / Improvement of knowledge about clogging stormwater infiltration systems

Gonzalez-Merchan, Carolina 15 May 2012 (has links)
Les ouvrages d’infiltration sont utilisés aujourd’hui comme alternative au réseau d’assainissement pluvial. Ils réduisent les risques d’inondation, contribuent au piégeage de polluants permettant ainsi de limiter la détérioration des milieux aquatiques superficiels et sont reconnus pour recharger la nappe. Cependant leur fonctionnement est affecté à long terme par le colmatage réduisant leur performance hydraulique. Par ailleurs, lorsque ces systèmes sont munis de surverses, le colmatage limite les capacités d’interception des flux d’eau et des polluants. Le colmatage constitue donc un facteur clé dans le fonctionnement de ces systèmes tant sur un plan hydraulique qu’environnemental. Cette thèse a pour but de mesurer et de comprendre l’évolution spatio-temporelle du colmatage à une échelle mégascopique (l’échelle d’un ouvrage extensif type) et diachronique (sur le moyen terme). Pour cela une approche expérimentale a été menée au sein de l’Observatoire de Terrain en Hydrologie Urbaine (OTHU) selon trois niveaux d’investigation sur un même ouvrage en conditions réelles de fonctionnement. Un premier niveau (échelle globale) a consisté à mesurer l’évolution temporelle du système pris dans son ensemble grâce au calage de la résistance hydraulique au sens du modèle de Bouwer. Cette étape a nécessité de mesurer et d’exploiter des données en continu de flux d’eau, de sédiments, de matière organique apportés au système, les facteurs environnementaux comme la température d’air et d’eau, l’ensoleillement, le rythme, la nature des événements pluvieux, la saisonnalité, etc., sur un historique de 8 ans. Cette étape nous a mis en évidence la dynamique d’évolution du colmatage et le rôle bénéfique du développement de la végétation sur le maintien de la capacité d’infiltration globale d’un ouvrage de ce type. Un deuxième niveau (échelle semi globale) nous permettant de distinguer l’évolution temporelle du colmatage du fond et des parois, a montré leur dynamique respective (rapide pour le fond, très lente voire inexistante pour les parois). Un troisième niveau (échelle locale) a tenté d’explorer la répartition spatiale et temporelle du colmatage sur le fond des ouvrages sur des échelles de temps plus courtes. L’approche expérimentale a consisté à caractériser la couche colmatante en terme physico chimique et dans une moindre mesure biologique (conductivité hydraulique à saturation, granulométrie, porosité, masse volumique apparente, masse volumique des particules solides, matière organique, biomasse). Elle a analysé également le rôle de la végétation spontanée sur la capacité d’infiltration vis-à-vis des caractéristiques de l’horizon de surface et la structure aérienne et racinaire des espèces présentes. Enfin des analyses statistiques de l’évolution du colmatage à chaque échelle a mis en évidence la part potentiellement importante du colmatage biologique sur ces systèmes alors que, pour la gestion des eaux pluviales ce facteur est généralement négligé. / Infiltration systems are widely used in urban stormwater management. Infiltration systems can significantly reduce stormwater discharges to sewer systems and may therefore contribute to the mitigation of flooding problems. In addition infiltrations systems also help to reduce stormwater pollution, contribute to groundwater recharge and to water course protection. However, the hydraulic performance of infiltration systems decreases with time due to clogging effects. A clogged layer limits the transfer of water and pollutants in infiltrations systems. The clogging has a significant impact on the long-term performance of a system. The aim of this PhD study is to better understand spatio-temporal evolution of clogging on large infiltration systems involving different scales: (i) global scale, (ii) semi - global (the whole bottom and the sides), (iii) local scale (different part of the bottom). An experimental approach has been carried out in the OTHU project (Field Observatory on Urban Hydrology, www.othu.org). An infiltration basin studied with three investigations scales under real operation conditions. In a global scale, the temporal clogging evolution of the system was evaluated in terms of hydraulic resistance. This clogging indicator was calibrated from Bouwer’s model. Water inflow, TSS, COD, climatic factors (air temperature and solar energy), stormwater events and season variations were measured. The results describe the clogging evolution over 8 years. It indicates that vegetation may have a beneficial effect on infiltration capacity. In a semi global scale study, clogging evolution at the bottom and the sides, of the infiltration basin was evaluated. It proved that the clogging mainly occurs at the bottom, that is, the bottom was clogged fast and the clogging at the sides was slow. Local scale study, spatial distribution and temporal evolution of clogging at the bottom with in situ measurements during 2 years were investigated. The study characterised the clogged layer, with bio physic-chemical parameters (i.e., were investigated hydraulic conductivity, porosity, grain size, dry bulk density, organic matter and biomass content). This analyze compared also the role of different types of spontaneous vegetation. The result showed the high spatio-temporal heterogeneity on the infiltration surface. Statistical analysis of clogging evolution in each scale showed the significant impacts of biological activity in the stormwater infiltration basins, which was often neglected
510

Bassin de retenue des eaux pluviales en milieu urbain : performance en matière de piégeage des micropolluants / Urban stormwater detention basin : performance in terms of micropollutant trapping

Sebastian, Christel 27 November 2013 (has links)
Les bassins de retenue des eaux pluviales constituent des éléments importants de gestion des rejets urbains de temps de pluie (RUTP). De nombreuses études montrent que, lorsqu’ils sont bien conçus, ils permettent de lutter contre les inondations et de décanter efficacement la pollution métallique et les hydrocarbures fortement fixés aux matières en suspension (MES). Le travail se propose d’étudier les performances de ce type de système afin d’en mesurer et d’en modéliser leur efficacité en termes d’abattement de micropolluants à une échelle évènementielle. Pour cela, il a été développé un suivi expérimental d’un bassin en service sec et étanche de grande taille localisé à l’exutoire d’un bassin versant drainé par un réseau d’assainissement séparatif pluvial faisant partie de l’Observatoire de Terrain en Hydrologie Urbaine (OTHU). Ainsi un total de 100 micropolluants (MP) a–t-il été suivi : 22 éléments traces métalliques (ETM), 16 hydrocarbures aromatiques polycycliques (HAP), 2 alkylphénols (AP), 5 alkylphénols éthoxylates (APEO), Bisphénol A, 9 polybromodiphényléthers (PBDE) et 45 pesticides. Dans les eaux, ils ont été analysés en phase dissoute et particulaire en entrée et en sortie. 67 % des MP recherchés ont été détectés au moins une fois en entrée ou en sortie. Les concentrations moyennes évènementielles à l’exutoire du bassin versant alimentant l’ouvrage sont comparables aux données de la littérature quand elles existent et montrent une grande variabilité. L’efficacité massique évènementielle (EME) de piégeage des MP a été évaluée selon différentes méthodes, prenant en compte les incertitudes totales. L’efficacité est avérée pour la majorité des ETM et HAP, sur un nombre limité de campagnes pour les PBDE et les APEO, très limité pour le 4-Tert-Octylphénol et le 4-Nonyphénol (1 sur 5). Les performances de l’ouvrage ont été mises en avant pour 7 pesticides (sur 15 détectés) mais des efficacités négatives témoignent d’un relargage possible des polluants. L’étude des sédiments accumulés dans le bassin depuis 6 ans montre qu’ils sont assez chargés tant en métaux, HAPs qu’en 4-Nonylphénol, BDE209 et Diuron. Enfin, nous avons expérimenté 3 niveaux de modèles afin d’identifier des pistes pertinentes pour la suite des travaux dans ce domaine. / Detention basins are at stake in urban stormwater discharges (USWD) management strategies. If well designed, they are not only used to mitigate stormwater flood impacts but also to trap metals and hydrocarbon compounds strongly bounded to total suspended solids (TSS). An experimental monitoring, in the framework the Field Observatory on Urban Hydrology (OTHU), was developed on a large dry detention basin located at the outlet of a catchment drained by a separate stormwater system. This basin presents a rather classical and current configuration.A sum of 100 substances was studied: 22 metals (ETM), 16 polycyclic aromatic hydrocarbons (PAH), 2 alkylphenols (AP), 5 ethoxylate alkylphenols (APEO), Bisphénol A, 9 polybromodiphenylethers (PBDE) and 45 pesticides. They were analyzed in both dissolved and particulate phases in water at the inlet and outlet of the device. 67% of MP studied was detected at least once at the inlet or outlet. Event mean concentrations were in the same range as literature data when available and showed an important variability.Event mass efficiency (EME) in trapping MP was assessed by different methods taking account for global uncertainties. Acceptable efficiency was found for most of ETM and PAH and in a lesser extent for PBDE and APEO on a limited number of campaign. The detention basin had only a positive impact on alkylphenols (4-Tert-Octylphenol and 4-Nonylphenol) for one campaign out 5. Negative values for 7 pesticides (among 15 detected) indicated possible pollutant release. Accumulated sediments study showed high MP concentrations in particular for metals, PAH, 4-Nonylphenol, BDE209 and Diuron. Lastly, different levels of models were tested to try to identify relevant ones for further work.

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