O presente trabalho teve como objetivo principal avaliar a performance e a estabilidade operacional de uma nova configuração de um reator anaeróbio híbrido (RAH) que combina um filtro anaeróbio de fluxo descendente seguido de uma câmara de manta de lodo de fluxo ascendente comparativamente ao reator UASB nas mesmas condições operacionais aplicados ao tratamento de esgoto sanitário. A avaliação da eficiência de remoção de remoção da matéria orgânica e dos sólidos suspensos nos reatores piloto foi por meio de testes da DQO, DBO, sólidos em suspensão totais (SST) e dos sólidos em suspensão voláteis (SSV).Os reatores UASB e RAH foram operados por um período de 240 dias na fase 1 e 150 dias na fase 2 com vazão afluente de 1,6 m3/h e TDH de 11,8 h. O TDH médio na câmara de entrada do RAH foi de 2,7h e de 9,1h na câmara ascendente de manto de lodo. Os reatores piloto apresentaram capacidade de tratamento para suportar os choques de carga orgânica devido à variabilidade do esgoto bruto. A eficiência de remoção de matéria orgânica em termos de DQO foi de 66% e 59% para o UASB e RAH, a eficiência de remoção de SST atingiu valores de 65% e 63% respectivamente, aliás, o reator UASB apresentando valores superiores de desempenho operacional em quase todos os parâmetros de monitoramento dos processos de digestão anaeróbia os valores médios dos parâmetros DQO, DBO5, SST e SSV não tiveram diferenças estatisticamente significativas. O pH para os sistemas piloto esteve na faixa ideal para o desenvolvimento dos microorganismos anaeróbios (6,5 a 7,5) e a alcalinidade e os AGVs demonstraram estabilidade dos reatores, corroborados pela estabilidade do pH no interior de cada sistema. A velocidade ascensional na câmara de manta de lodo (0,45 m/h) não causou efeito adverso na qualidade do efluente em termos de SST, com valor médio de 39,8 mg/L, na mesma faixa observada no reator UASB (41,6 mg/L). Foi observada menor concentração de biomassa no reator RAH (distribuição vertical) comparativamente ao reator UASB segundo os perfis verticais de lodo, entretanto, este fato não comprometeu a sua eficiência de remoção de matéria orgânica e dos sólidos suspensos. A retirada do lodo de excesso dos sistemas piloto foi baseada na relação STV/ST para estimar a fração de biomassa, a freqüência do descarte foi de 1 vez por mês retirando o equivalente aos 10% do volume de lodo das tomadas que apresentaram uma fração de STV menor que 50%. É viável a implementação da turbidez como parâmetro de detenção de perdida de lodo no efluente dos reatores anaeróbios devido a que a turbidez e os SST apresentaram uma relação direta o que ajudaria a simplificar mecanismos de controle operacional para a toma de decisões nas estações de tratamento, sendo que a turbidez é um parâmetro de leitura rápida “in situ” e poderia advertir do excesso de lodo ao interior do reator. Foram empregados diferentes métodos titrimétricos para a determinação dos AGVs no efluente do RAH e UASB. Após análise dos resultados, recomenda-se o uso do método de KAPP e RIPLEY para a determinação dos AGVs pela simplicidade metodológica e pela rapidez na obtenção do resultado. / This study aimed to evaluate the performance and operational stability of a new configuration of a hybrid anaerobic reactor (RAH) combining an anaerobic filter downflow followed by a sludge blanket chamber upflow compared to UASB in same operating conditions applied to sewage treatment. The evaluation of organic matter removal and removal efficiency of suspended solids in the pilot reactor was by testing COD, BOD, total suspended solids (TSS) and volatile suspended solids (VSS). The RAH and UASB reactors were operated for a period of 240 days in the first phase and 150 days in phase 2 with the inlet flow of 1,6 m3/h and 11,8h TDH. The average TDH RAH in the inlet chamber was 2.7h and 9,1h in ascending chamber sludge blanket. Pilot reactors showed treatment capacity to support organic shock loads due to the variability of raw sewage. The organic matter removal efficiency in terms of COD was 66% and 59% for the UASB and RAH, the TSS removal efficiency reached values of 65% and 63% respectively, by the way, the UASB presenting performance values higher operational in almost all parameters of the monitoring anaerobic digestion processes mean values of the parameters COD, BOD5, TSS and VSS were not statistically significant differences. The pH for the pilot systems was in the ideal range for the development of anaerobic microorganisms (6,5 to 7,5) and alkalinity and Volatile Fatty Acids (VFA) demonstrated stability of reactors corroborated by the pH stability within each system. The upflow velocity in the sludge blanket chamber (0,45 m/h) caused no adverse effect on effluent quality in terms of TSS, with an average of 39,8 mg/L, in the same range observed in UASB (41,6 mg/L). It was observed lower concentration of biomass in the reactor RAH (vertical distribution) compared to UASB second vertical sludge profiles, however, this fact did not compromise its removal efficiency of organic matter and suspended solids. The withdrawal of the pilot systems excess sludge was based on TSV/TS ratio to estimate the biomass fraction, the frequency of disposal was 1 once a month by removing the equivalent of 10% of the outlets sludge volume that had a fraction of TSV less than 50%. The implementation of turbidity as sludge lost detention parameter is viable in the effluent of the anaerobic reactors due to turbidity and TSS showed a direct relationship which would help simplify operational control mechanisms for decision making in treatment plants, wherein the turbidity is a quick read parameter "in situ" and could warn of excess sludge inside the reactor. Different titrimetric methods were employed for the determination of VFA and the effluent from the UASB and RAH. After analyzing the results, we recommend the use of KAPP and RIPLEY method for the determination of VFA by methodological simplicity and speed in obtaining results.

Orientador: Francisco Sekiguchi de Carvalho e Buchmann / Resumo: Estuários são ambientes heterogêneos, altamente complexos, e condicionados por diversos fatores ambientais. Nenhum estuário é igual a outro, e é esta diversidade que os torna tão importantes do ponto de vista da conservação. A grande quantidade de recursos naturais disponíveis nesses ambientes favorece o desenvolvimento de assentamentos urbanos nas suas margens, podendo comprometer o equilíbrio natural. A partir do conhecimento detalhado dos sistemas estuarinos é possível traçar metas assertivas para a conservação e gestão destes ambientes tão singulares. O presente estudo visa a caracterização e comparação dos estuários dos rios Itaguaré e Guaratuba (Bertioga, SP) quanto aos seus parâmetros geo-físico-químicos. A área de estudo está localizada na planície costeira da Bacia Hidrográfica da Baixada Santista e inserida no Parque Estadual Restinga de Bertioga. Foram realizados levantamentos semestrais de batimetria e imageamento com sonar de varredura lateral, com o intuito de conhecer as profundidades e feições de fundo dos estuários, avaliando a dinâmica de processos erosivos e deposicionais. Medições mensais de salinidade, temperatura e turbidez foram realizadas ao longo de um ano, visando avaliar o comportamento sazonal da intrusão salina e da zona de máxima turbidez. Para verificar variações na granulometria, foram coletadas amostras de sedimentos nos mesmos pontos de medição das variáveis físico-químicas da água. Os resultados foram avaliados de forma integrada, utilizando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Estuaries are highly complex heterogeneous environments, conditioned by different environmental factors. Every estuary has particular characteristics, and this diversity makes them so important for conservation. The great amount of available natural resources in these environments contributes to urban settlement developments on their surroundings, which may compromise their natural balance. Detailed knowledge of estuarine systems helps establish assertive goals for the conservation and management of these unique environments. This study aims to characterize and compare Itaguaré and Guaratuba estuaries (Bertioga, SP) regarding their geophysical-chemical characteristics. The study area is located on the Baixada Santista Basin’s coastal plain, and inserted in the Restinga of Bertioga State Park. Biannual bathymetry and side scan sonar surveys were carried in order to evaluate erosive and depositional processes affecting depths and bottom features of the estuaries. Salinity, temperature and turbidity measurements were carried out monthly over a period of one year to evaluate seasonal behavior of saline intrusion and the estuarine turbidity maximum. Sediment samples were collected in order to verify granulometry variations. Results were evaluated in an integrated manner, using geoprocessing and spatial analysis techniques, coupled with secondary data of mareography and precipitation, analyzing the influence of meteoceanographic factors in the water column and the background config... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-12-17T15:01:27Z (GMT). No. of bitstreams: 1 BrunoCB_DISSERT.pdf: 4196751 bytes, checksum: 815046ef78a951368bb3e92819e92b89 (MD5) Previous issue date: 2012-05-04 / The pegmatite rocks in Rio Grande do Norte are responsible for much of the production of industrial minerals like quartz and feldspar. Quartz and feldspar are minerals from pegmatite which may occur in pockets with metric to centimetric dimensions or as millimetric to sub millimetric intergrowths. The correct physical liberation of the mineral of interest, in case of intergrowths, requires an appropriate particle size, acquired by size reduction operations. The method for treating mineral which has a high efficiency fines particles recovery is flotation. The main purpose of the present study is to evaluate the recovery of quartz and potassium feldspar using cationic diamine and quaternary ammonium salt as collectors by means of dissolved air flotation DAF. The tests were performed based on a central composite design 24, by which the influence of process variables was statistically verified: concentration of the quaternary ammonium salt and diamine collectors, pH and conditioning time. The efficiency of flotation was calculated from the removal of turbidity of the solution. Results of maximum flotation efficiency (60%) were found in the level curves, plotted in conditions of low concentrations of collectors (1,0 x 10-5 mol.L-1). These high flotation efficiencies were obtained when operating at pH 4 to 8 with conditioning time ranging from 3 to 5 minutes. Thus, the results showed that the process variables have played important roles in the dissolved air flotation process concerning the flotability of the minerals. / No Rio Grande do Norte os pegmatitos respondem por grande parte da produ??o dos minerais industriais quartzo e feldspato. O quartzo e feldspato dos pegmatitos podem ocorrer em bols?es com dimens?es centim?tricas a m?tricas ou na forma de intercrescimentos milim?tricos a submilim?tricos. No caso dos intercrescimentos, a libera??o f?sica correta do mineral de interesse envolve a adequa??o granulom?trica atrav?s de opera??es de redu??o de tamanho. O m?todo no tratamento mineral que apresenta alta efici?ncia na recupera??o de finos ? a flota??o. O presente trabalho tem como objetivo principal avaliar a recupera??o de quartzo e feldspato pot?ssico utilizando os coletores cati?nicos diamina e sal quatern?rio de am?nio no processo de flota??o por ar dissolvido FAD. Os testes foram realizados baseados em um planejamento central composto 24, atrav?s do qual verificou-se estatisticamente a influ?ncia das vari?veis de processo: concentra??o dos coletores sal quatern?rio de am?nio e diamina, pH e tempo de condicionamento. A efici?ncia de flota??o foi calculada a partir do grau de remo??o de turbidez da solu??o. Resultados de m?xima efici?ncia de flota??o (60%) foram encontrados nas curvas de n?vel, plotadas nas condi??es de baixas concentra??es dos coletores (1,0x10-5 mol.L-1). Estas altas efici?ncias de flota??o foram obtidas operando-se na faixa de pH 4 8 com tempo de condicionamento variando de 3 a 5 minutos. Sendo assim, os resultados obtidos mostraram que as vari?veis de processo desempenharam pap?is importantes no processo de flota??o por ar dissolvido em rela??o ? flotabilidade dos minerais.

O presente trabalho teve como objetivo principal avaliar a performance e a estabilidade operacional de uma nova configuração de um reator anaeróbio híbrido (RAH) que combina um filtro anaeróbio de fluxo descendente seguido de uma câmara de manta de lodo de fluxo ascendente comparativamente ao reator UASB nas mesmas condições operacionais aplicados ao tratamento de esgoto sanitário. A avaliação da eficiência de remoção de remoção da matéria orgânica e dos sólidos suspensos nos reatores piloto foi por meio de testes da DQO, DBO, sólidos em suspensão totais (SST) e dos sólidos em suspensão voláteis (SSV).Os reatores UASB e RAH foram operados por um período de 240 dias na fase 1 e 150 dias na fase 2 com vazão afluente de 1,6 m3/h e TDH de 11,8 h. O TDH médio na câmara de entrada do RAH foi de 2,7h e de 9,1h na câmara ascendente de manto de lodo. Os reatores piloto apresentaram capacidade de tratamento para suportar os choques de carga orgânica devido à variabilidade do esgoto bruto. A eficiência de remoção de matéria orgânica em termos de DQO foi de 66% e 59% para o UASB e RAH, a eficiência de remoção de SST atingiu valores de 65% e 63% respectivamente, aliás, o reator UASB apresentando valores superiores de desempenho operacional em quase todos os parâmetros de monitoramento dos processos de digestão anaeróbia os valores médios dos parâmetros DQO, DBO5, SST e SSV não tiveram diferenças estatisticamente significativas. O pH para os sistemas piloto esteve na faixa ideal para o desenvolvimento dos microorganismos anaeróbios (6,5 a 7,5) e a alcalinidade e os AGVs demonstraram estabilidade dos reatores, corroborados pela estabilidade do pH no interior de cada sistema. A velocidade ascensional na câmara de manta de lodo (0,45 m/h) não causou efeito adverso na qualidade do efluente em termos de SST, com valor médio de 39,8 mg/L, na mesma faixa observada no reator UASB (41,6 mg/L). Foi observada menor concentração de biomassa no reator RAH (distribuição vertical) comparativamente ao reator UASB segundo os perfis verticais de lodo, entretanto, este fato não comprometeu a sua eficiência de remoção de matéria orgânica e dos sólidos suspensos. A retirada do lodo de excesso dos sistemas piloto foi baseada na relação STV/ST para estimar a fração de biomassa, a freqüência do descarte foi de 1 vez por mês retirando o equivalente aos 10% do volume de lodo das tomadas que apresentaram uma fração de STV menor que 50%. É viável a implementação da turbidez como parâmetro de detenção de perdida de lodo no efluente dos reatores anaeróbios devido a que a turbidez e os SST apresentaram uma relação direta o que ajudaria a simplificar mecanismos de controle operacional para a toma de decisões nas estações de tratamento, sendo que a turbidez é um parâmetro de leitura rápida “in situ” e poderia advertir do excesso de lodo ao interior do reator. Foram empregados diferentes métodos titrimétricos para a determinação dos AGVs no efluente do RAH e UASB. Após análise dos resultados, recomenda-se o uso do método de KAPP e RIPLEY para a determinação dos AGVs pela simplicidade metodológica e pela rapidez na obtenção do resultado. / This study aimed to evaluate the performance and operational stability of a new configuration of a hybrid anaerobic reactor (RAH) combining an anaerobic filter downflow followed by a sludge blanket chamber upflow compared to UASB in same operating conditions applied to sewage treatment. The evaluation of organic matter removal and removal efficiency of suspended solids in the pilot reactor was by testing COD, BOD, total suspended solids (TSS) and volatile suspended solids (VSS). The RAH and UASB reactors were operated for a period of 240 days in the first phase and 150 days in phase 2 with the inlet flow of 1,6 m3/h and 11,8h TDH. The average TDH RAH in the inlet chamber was 2.7h and 9,1h in ascending chamber sludge blanket. Pilot reactors showed treatment capacity to support organic shock loads due to the variability of raw sewage. The organic matter removal efficiency in terms of COD was 66% and 59% for the UASB and RAH, the TSS removal efficiency reached values of 65% and 63% respectively, by the way, the UASB presenting performance values higher operational in almost all parameters of the monitoring anaerobic digestion processes mean values of the parameters COD, BOD5, TSS and VSS were not statistically significant differences. The pH for the pilot systems was in the ideal range for the development of anaerobic microorganisms (6,5 to 7,5) and alkalinity and Volatile Fatty Acids (VFA) demonstrated stability of reactors corroborated by the pH stability within each system. The upflow velocity in the sludge blanket chamber (0,45 m/h) caused no adverse effect on effluent quality in terms of TSS, with an average of 39,8 mg/L, in the same range observed in UASB (41,6 mg/L). It was observed lower concentration of biomass in the reactor RAH (vertical distribution) compared to UASB second vertical sludge profiles, however, this fact did not compromise its removal efficiency of organic matter and suspended solids. The withdrawal of the pilot systems excess sludge was based on TSV/TS ratio to estimate the biomass fraction, the frequency of disposal was 1 once a month by removing the equivalent of 10% of the outlets sludge volume that had a fraction of TSV less than 50%. The implementation of turbidity as sludge lost detention parameter is viable in the effluent of the anaerobic reactors due to turbidity and TSS showed a direct relationship which would help simplify operational control mechanisms for decision making in treatment plants, wherein the turbidity is a quick read parameter "in situ" and could warn of excess sludge inside the reactor. Different titrimetric methods were employed for the determination of VFA and the effluent from the UASB and RAH. After analyzing the results, we recommend the use of KAPP and RIPLEY method for the determination of VFA by methodological simplicity and speed in obtaining results.

Made available in DSpace on 2014-07-29T15:01:52Z (GMT). No. of bitstreams: 1 dissertacao daniela camplesi.pdf: 1230668 bytes, checksum: 56ed1f54e5e43d735ad2b69bff069adc (MD5) Previous issue date: 2009-12-18 / The present work has evaluated the efficiency of an MSF system for treating supplying water on a pilot scale. A MSF pilot plant was located in the Water Treatment Station (WTS) area in Goianápolis- GO and fed by Sozinha stream. The plant was comprised of a dynamic prefilter (DPF) and a vertical upflowing pre-filter (VUF) in layers, both of them with different granular compositions; a slow sand filter (SSF); and a slow sand filter with activated carbon (SSFAC), which was called SEQ. 1. The second sequence of the trial, SEQ. 2, was comprised of a dynamic pre-filter (DPF) and a slow sand filter (SSF-2). The filtration rates in use were 24 and 48 m3/m2 a day for DPF, 12 e 24 m3/m2. day for APF; 3 e 6 m3/m2. day for SSF and SSFAC. The efficiency was evaluated by analyzing turbidity, apparent color, total suspended solids (TSS), as well as total thermo tolerant coliforms. The following items were evaluated: the filtration rates ranging effect onto the MSF unit trial system efficiencies; the MSF system efficiency comparison to the WTS complete cycling treatment; and the correlations between turbidity, color, and coliforms removals and the TSS removals. The results obtained from the trials have shown that DPF and VUF are important units for microorganisms and solid particles retaining, for it prepares the effluent in order to submit it into slow filtration. They have also shown that they make it possible for the roughing filtration to last longer. Generally put, it presents that the slow filters are significantly and above 90% efficient in removing TSS, color and turbidity, and 99% efficient in removing total coliforms and thermotolerant coliforms in all roughing filtration. After comparing the quality of both the water produced by MSF and the one by the complete cycling WTS, it was noticed that MSF produces water with quality similar to the complete cycling WTS. The range for the filtration rates has had significant influence only in the removal efficiencies of color and turbidity. There isn t correlation among the removals of the parameters color, turbidity, TSS and coliforms but for the correlation among apparent color and true color. The experiment results suggest that MSF technology, when suitably operated, it is a viable system for the treatment of supplying water and produced water with low levels of color, turbidity, TSS and coliforms is that 40% of the samples, provided drinking water under conditions compatible to those established by Decree 518/2004 of the Ministry of Health (BRAZIL, 2004) for human consumption / O presente trabalho avaliou a eficiência de um sistema de FiME no tratamento de águas de abastecimento em escala piloto. A instalação piloto FiME, localizada na área da Estação de Tratamento de Água (ETA) de Goianápolis, GO e alimentada pelo Ribeirão Sozinha, era composta de um pré-filtro dinâmico (PFD), um pré-filtro com escoamento vertical ascendente (PFA) em camadas, ambos com composições granulométricas diferenciadas, um filtro lento de areia (FLA) e um filtro lento de areia com carvão ativado (FLAC) e foi denominada SEQ 1. A SEQ 2 do experimento era constituída de um pré-filtro dinâmico (PFD) e um filtro lento de areia (FLA-2). As taxas de filtração utilizadas foram 24 e 48 m3/m2. dia para PFD, 12 e 24 m3/m2. dia para PFA, 3 e 6 m3/m2. dia para FLA e FLAC. A eficiência foi avaliada por meio das análises de turbidez, cor aparente, sólidos suspensos totais (SST) e coliformes totais e termotolerantes. Foi avaliado também o efeito da variação das taxas de filtração nas eficiências das unidades do sistema FiME, a comparação da eficiência do sistema FiME com o tratamento de ciclo completo da ETA e as correlações entre as remoções de turbidez, cor, coliformes e a remoção de SST. Os resultados obtidos nos experimentos demonstraram que o PFD e PFA são unidades importantes para a retenção de partículas sólidas e microorganismos, preparando o afluente para ser submetido à filtração lenta e possibilitam maior duração das carreiras de filtração. De maneira geral, os filtros lentos apresentaram eficiências significativas e superiores a 90% para remoção de cor, turbidez, SST e 99,9% de eficiência para remoção de coliformes totais e termotolerantes em praticamente todas as carreiras de filtração. Quando comparada a qualidade da água produzida pelo sistema FiME com a ETA de ciclo completo, verificou-se que a FiME produz água com qualidade similar à ETA de ciclo completo. As variações das taxas de filtração influenciaram significativamente nas eficiências de remoção de cor e turbidez. Não há correlação entre as remoções dos parâmetros cor, turbidez, SST e coliformes mas há correlação para cor aparente e cor verdadeira. Os resultados obtidos nos experimentos sugerem que a tecnologia de FiME, quando operada adequadamente, é um sistema viável para o tratamento de águas de abastecimento e produziu água com baixos teores de cor, turbidez, SST e coliformes sendo que em 40% das amostras analisadas, proveu água potável em condições compatíveis às estabelecidas pela Portaria 518/2004 do Ministério da Saúde (BRASIL, 2004) para consumo humano

The government of Ethiopia has initialized an investment in the agricultural sector in order to secure food production for a growing population. The Koga Irrigation and Water Management Project is a pilot project and hopes are that crop production will double. Water quality is an important factor to meet these expectations. The aim of this study is to assess the irrigation water’s biological and chemical quality by using locally available methods and compare the results with international water quality standards pertaining to agricultural use as well as human and animal consumption. The water was sampled and analyzed for biological, chemical and physical parameters. The most important parameters were thermotolerant coliforms, electrical conductivity and turbidity. The first part of the thesis was a literature study dealing with the Koga project and the water use in the area. The second part focuses on 17 water samples that were taken within an individual command area: irrigation canals, fish pond and drinking water well. The samples were then analyzed at the water quality and treatment lab at the University of Bahir Dar. The results were compared to guideline values for livestock, crop, fish and human use recommended by the World Health Organization (WHO). All water samples, including the drinking water from the groundwater well, were contaminated with thermotolerant coliforms and had a relatively high turbidity. Additionally, the irrigation water contained levels of boron which were higher than recommended for crop production. Electrical conductivity values were overall satisfactory. These results give only an idea of the overall water quality within the Koga Irrigation Project. More samples need to be taken in order to draw any concrete conclusions and provide any recommendations.

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.

Les estuaires macrotidaux tels que l'estuaire de la Charente sont le siège d'une interaction constante entre la marée et le débit fluvial. L'objectif de ce travail est d'étudier le comportement de l'estuaire en fonction de ces forçages, et de déterminer leur impact sur les distributions horizontale et verticale de la salinité et des sédiments fins cohésifs. Un modèle tridimensionnel hydrosédimentaire a été mis en place sur l'estuaire afin de reproduire la dynamique estuarienne observée dans la Charente. Ce modèle a été validé via l'obtention de mesures in-situ venant également appuyer et compléter les simulations de réponse aux forçages effectuées. Dans l’estuaire de la Charente, l'asymétrie de la marée présente la particularité de s’inverser en fonction du cycle morte-eau/vive-eau. Le modèle a permis de déterminer l'influence de la marée incidente et de la morphologie de l'estuaire sur ce comportement, et d'évaluer son impact sur la salinité et la dynamique sédimentaire de l'estuaire. L'évolution globale de la marée lors de sa propagation dans l'estuaire a été étudiée, ainsi que l'influence du débit fluvial sur la circulation estuarienne, l'intrusion saline, et la stratification. Les résultats montrent que l'embouchure de l'estuaire reste dominée par la marée même en cas de crue, et que la stratification est inversement proportionnelle au débit fluvial. Le bouchon vaseux est reproduit par le modèle hydrosédimentaire, et ses variations en fonction des cycles de marée flot/jusant et morte-eau/vive-eau sont étudiées. La marée est le processus dominant dans la formation et le déplacement du bouchon vaseux. Les simulations montrent cependant une forte influence du débit fluvial sur sa géométrie et sa concentration, particulièrement en crue où il est plus compact et se déplace sur une distance plus courte. Les flux sédimentaires et les observations faites sur le terrain suggèrent que les sédiments sont importés dans l'estuaire en régime fluvial moyen et d'étiage, et qu'un envasement se produit. En crue, le bouchon vaseux est maintenu à 10 km en aval de l'embouchure et un export de sédiments vers la baie de Marennes-Oléron est obtenu. / Macrotidal estuaries such as the Charente estuary are characterized by a constant interaction between the tides and the river runoff. The aim of this work is to study the estuary behavior in function of these forcings, and to determine their impact of the horizontal and vertical distributions of salinity and fine cohesive sediments. A three-dimensional model was developed to reproduce the estuarine dynamics observed in the Charente estuary. This model was validated using in-situ measurements, which can also confirm and provide additional information when compared to the different forcing simulations. In the Charente estuary, the tidal asymmetry is characterized by its inversions in function of the neap/spring tidal cycle. The model was used to determine the influence of the incident tide and the estuarine morphology on this behavior, and to evaluate its impact on salinity and sediment dynamics in the system. The overall evolution of the tide during its propagation in the estuary was studied, together with the river runoff influence on the estuarine circulation, the saline intrusion and stratification. Results show that the estuary mouth stays tide-dominated even in the event of a flood, and that stratification is inversely proportional to the river runoff. The turbidity maximum is well reproduced by the hydrosedimentary model, and its variations infunction of the flood/ebb and neap/spring tidal cycles are studied. Tidal forcing is the main mechanism leading to the formation and movement of the turbidity maximum. However, simulations show a strong influence of the river runoff on its geometry and concentration, especially when the runoff is high. The turbidity maximum is then more compact and moving on shorter distances. Calculated sedimentary fluxes and observations made on the field suggest that sediments are imported in the estuary for low and medium river runoffs, and that siltation is occurring. In the event of a flood, the turbidity maximum is maintained 10km upstream of the mouth and sediments are exported into the Marennes-Oléron bay.

Les courants de turbidité dans les canyons sous-marins contribuent largement au transfert sédimentaire à travers des marges continentales. L’étude géologique des canyons sous-marins et des systèmes turbiditiques associés a permis des avancées fondamentales dans la compréhension de l’évolution des courants de turbidité.Ces études sont cependant limitées à des interprétations a posteriori, basées sur la répartition des dépôts et des évidences morphologiques. Cette thèse vise à l’application de la modélisation numérique des courants de turbidité, sur la base des processus physiques, à deux canyons sous-marins de la côte Méditerranée Occidentale.Des courants de turbidité liés au chalutage de fond sont modélisés dans le canyon de La Fonera. Les résultats du modèle permettent de spatialiser ce transport; ainsi le modèle peut être un point de départ pour l’identification de zones de pêche au chalut avec un moindre impact. L’absence d’un plateau continental au niveau de Nice a permis une alimentation continue du système turbiditique du Var indépendamment des variations du niveau marin. Ainsi ce système s’avère un laboratoire naturel pour l’étude du contrôle climatique sur l’activité turbiditique. L’influence des forces de Coriolis dans l’évolution spatiale des courants de turbidité et dans la construction de la Ride sédimentaire du Var est modélisée et mise en évidence pour la première fois.La modélisation numérique des courants de turbidité ne peut pas fournir à présent des résultats de qualité prédictive du fait de la quantité limitée d’information disponible pour établir les conditions initiales de l’écoulement qui impactent largement son évolution et dépôts. Malgré ce fait, la modélisation numérique permet d’élargir les interprétations du fonctionnement sédimentaire des canyons étudiés, d’identifier les chemins empruntés par les écoulements et leur dépôt final et de mieux préparer des cibles (mouillages et carottage) lors des campagnes à la mer. / Turbidity currents in submarine canyons are the main contribution for sediment transfer across the continental margins. Geological studies of submarine canyons and associated turbiditic systems for more than 30 years led to an extraordinary breakthrough in the understanding of how turbidite systems evolve. However, these studies remain limited to a posteriori interpretations, based on the distribution of deposits and morphological evidences. The overarching aim of this thesis is to apply a 2DH process-based model to simulate large-scale turbidity currents on two different submarine canyons in the western Mediterranean coast.The work in La Fonera canyon, in the Catalan margin, focuses on the modelling of sediment transport and accumulation resulting from trawling activities on the canyon flanks. The numerical process-based provides a 3D visualization of potential trawling impacts on sediment dynamics. The study represents a starting point for the assessment of the sedimentary impact of bottom trawling in deep continental margins. The present work can help in the identification of trawling areas with lesser impacts. The Var Sedimentary System, located in the vicinity of Nice (France), is connected to the Var River during both low and high-stands and it can be considered as a natural laboratory for the study of the climatic control on the turbiditic activity. The influence of Coriolis forces on the spatial evolution of the hyperpycnal flows and hence in the construction of the Var Sedimentary Ridge (VSR) is evidenced and supported for the first time.The major drawback is the limited amount of information for the necessary initial and boundary conditions; hence modelling results might not be of predictive quality. However, modelling results provide a full-scale vision of the system allowing the identification of sediment pathways and deposition areas on the basis of physical processes and enlarge the present knowledge of the canyons studied. The results obtained may help in the identification of strategic mooring and coring sites to further advance the state of our knowledge on sediment dynamics of the different cases studies.

Le système turbiditique du Var présente la particularité d’être fréquemment parcouru par des écoulements gravitaires. Cela en fait un endroit privilégié pour étudier simultanément les facteurs déclenchant des courants de turbidité, leurs caractéristiques hydrodynamiques, leur contenu particulaire et les dépôts associés. Dans le cadre du projet Européen HERMES (6ème Programme Cadre), nous avons acquis pendant 2 ans dans le canyon du Var et dans la vallée turbiditique (1) des séries temporelles dans la colonne d’eau (30 m et 400 m au dessus du fond) sur la vitesse des courants, la température et le flux particulaire, et (2) des prélèvements répétés par carottage du sédiment de surface (...) / In the framework of the HERMES European project, this study aims to characterize the sedimentary processes acting in the Var turbiditic system, their impact on the morphology, and their evolution through time and space. This work uses data acquired along the system, including interface cores, acoustic data, and measurement in the water column (temperature, particulate fluxes, speed and direction of the currents) thanks to mooring lines. The Var turbiditic system is under the influences of the Northern Current and of the Var river by a direct connection. Sedimentary processes are related to gravity-driven currents, oceanic currents which remobilizes sediments and hemipelagic decantation. Gravity-driven processes are dominant and are responsible of 80% of the mean annual sedimentary transport in the system, at the scale of two years (2005-2007). They are characterized by a mean speed of 100 to 600 mm.s-1 and a mean particulate flux of 10 to more than 400 g.m-2.j-1. The combination of the river discharge data and our in-situ measures allows to discriminate the mechanism responsible of their triggering: mass-wasting or river floods. Hyperpycnal turbidity currents, generated by the plunging of the turbid plume are observed for flood extended to the whole hydrographic system, with a river discharge of more than 306 m.s-1 at the river mouth (...)