Climate change has already led to an increase in the frequency and intensity of storm events in many parts of the world. With further increases predicted, and growing evidence of the link between extreme precipitation and waterborne disease, it is important to elucidate the role of sediments in pathogen transmission. Intense rainfall can trigger discharges from combined sewer overflows, increase surface and subsurface faecal inputs and can re-suspend microorganisms already present in sediments. Previous research has shown that sediments can act as environmental reservoirs of numerous waterborne pathogens, including enteric viruses and antibiotic resistant bacteria. Sediments are therefore a growing public health concern and are an increasing focus of human health protection strategies. However, further research is needed in order to elucidate the behaviour of microorganisms within these matrices. Routine monitoring for pathogens within sediments has not to date been considered feasible in many parts of the world and although low-cost microbial tools to detect faecal pollution of human origin, such as those that detect phages infecting Bacteroides fragilis (GB-124), have shown promise in many situations, they have seldom been applied to sediment matrices. Sediments might offer a more sensitive and longer-term assessment of contamination sources and hazards to health, compared with analysis of overlying waters from the same location. This study therefore sought to determine an effective elution method to extract GB-124 phages from sediments and to use it in an intensive six month investigation of the River (Ouse) catchment in Southeast England. The results (ANOVA with post-hoc Tukey) revealed that a low-cost elution method, involving 10% beef extract, provided the most effective means of recovering GB-124 phage from a range of river sediments (66% recovery). GB124 phages were subsequently enumerated in sediment and overlying water collected from 25 sites across the study catchment, along with somatic coliphage (SC), faecal coliforms (FC), and intestinal enterococci (IE). Physicochemical data were also collected. Analyses revealed evidence of faecal contamination at all sites, and human contamination at 13 of the 25 sites. Whilst levels of microorganism in the water and sediment were significantly correlated: GB-124 (p= 0.015); SC (p= 0.000); FC (p= 0.018); and IE (p= 0.038), importantly GB-124, SC, FC and IE (p= 0.00) were detected at significantly higher levels (Mann-Whitney) in the sediment samples. Significant correlations (p= < 0.01) were also observed between levels of FC, IE and SC and sediment temperature, but not between water temperature and any of the parameters in the water column. Interestingly, GB-124 phage showed no significant correlation with the non human-specific parameters (SC, FC, and IE) in the sediment matrices, which were found to co-correlate with one another (p= 0.00). The findings suggest that the application of low-cost monitoring approaches to analyse river sediments may not only provide a better assessment of dominant pollution sources than grab samples of overlying water (due to the higher levels and incidence of phages in sediments), but that they may also provide a better indication of potential risks to health from human enteric viruses. As such, the findings of this study add significantly to the body of extant knowledge relating to the behaviour of GB-124 phages in the environment and further support their use for microbial source tracking (MST) and as a potential component of quantitative microbial risk assessment (QMRA) studies.

Orientadores: Jaime Aparecido Cury, Maria da Luz Rosário de Souza / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T23:45:25Z (GMT). No. of bitstreams: 1 Olivati_FabricioNarciso_M.pdf: 1421576 bytes, checksum: 7452ca55c9e7c3647fd3f2ade8146c3d (MD5) Previous issue date: 2011 / Resumo: O objetivo do estudo foi avaliar a qualidade da concentração de fluoreto na água de abastecimento público de Capão Bonito, analisando os registros históricos do controle operacional feito pela SABESP e fazendo durante um ano uma comparação em tempo real com resultados de um heterocontrole. Foram avaliados registros feitos de 2005 a 2009, totalizando 1964 analises, e durante 2009 a 2010 foram coletadas 120 amostras de água de 10 pontos da rede de abastecimento do município para determinação da concentração de fluoreto, as quais foram comparadas com os registros das analises do controle operacional do mesmo período. As concentrações de fluoreto foram determinadas em duplicatas, usando eletrodo íon específico. As amostras foram classificadas quanto à concentração de fluoreto para as condições climáticas da região em: abaixo do mínimo (< 0,6 mg F/L); acima do máximo (>0,8 mg F/L) e na faixa ideal (0,6 a 0,8 mg F/L). De acordo com os registros do controle operacional, em média 76, 3 % das amostras de água de 2005 a 2009 apresentaram concentração de fluoreto dentro da faixa ideal, mas com variabilidade entre <0,10 a 5,43 mg F/L. Os dados do heterocontrole, feito de 2009 a 2010, mostrou concentrações que variaram entre <0,08 e 1,8 mg F/L com média de 80,8% de concentrações ideais. Em média, houve concordância com os registros do controle operacional feito no mesmo período, mas houve discordância entre os resultados das porcentagens de amostras abaixo e acima dos limites da faixa ideal. Os resultados mostram que a fluoretação da água de Capão Bonito tem sido feita com regularidade, porém ações de vigilância visando seu aperfeiçoamento são necessárias para garantir melhor qualidade da água consumida pela população / Abstract: The aim of this study was to evaluate the quality of the fluoride concentration in the public water supply of Capão Bonito, SP, analyzing the data collected from operational control and the results of an external control. We evaluated the historical records of the operational control of SABESP, totaling 1964 samples between 2005 and 2009. Additionally, from 2009 to 2010 120 water samples were collected from 10 water supply points at strategic locations in the county, and analyzed for fluoride content. We also compared the records of operational control samples with the results of the external control, in the same study period. The fluoride concentrations were determined by ion-specific electrode, in duplicate. The samples were qualified according to the fluoride concentrations, and classified based on the local climatic conditions as: below the minimum (< 0.6 mg F/L), above the maximum (> 0.8 mg F/L) and ideal (0.6 to 0.8 mg F/L). According to the analysis of operational control, the average or optimal concentrations within the accepted standards between 2005 and 2009 was 76.3%, with minimum and maximum concentrations of < 0.10 and 5.43 mg F/L. The external control, from 2009 to 2010, showed concentrations ranging from < 0.08 to 1.8 mg F/L and 80.8% of samples within optimal concentrations. There was an agreement on the outcome for the comparison between the operational and the external control, although the percentages of samples above and below the optimum were different. According to the results, water fluoridation in Capão Bonito is regularly maintained; however, surveillance, targeting a higher effectiveness of fluoridation is necessary to ensure the quality of water consumed by the population / Mestrado / Odontologia em Saude Coletiva / Mestre em Odontologia em Saúde Coletiva

Orientador: Edevar Luvizotto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-19T05:21:31Z (GMT). No. of bitstreams: 1 Yoshikawa_AndreaManami_M.pdf: 2628428 bytes, checksum: 290bc37f63de4e2f4b6fe722bd4a7c43 (MD5) Previous issue date: 2011 / Resumo: Um estudo detalhado dos programas EPANET versão padrão e EPANET-MSX tornam-se relevante, no cenário nacional, como uma importante ferramenta, para avaliação da qualidade do produto transportado ao longo da rede de distribuição. Simulações de casos hipotéticos foram realizadas tendo por base as condições de: decaimento de cloro de múltiplas origens; oxidação, transferência de massa e adsorção do arsênio; recrescimento bacteriano com inibição de cloro; e decomposição da cloramina. A análise detalhada destes programas e a aplicação desses em estudo de casos, desenvolvidos nessa dissertação, objetivou contribuir para ampliar o conhecimento sobre os problemas da modelação computacional de qualidade de água em sistemas de abastecimento e distribuição de água / Abstract: A detailed study of computer programs EPANET standard version and EPANET-MSX, extended version for multiple species, becomes relevant since, only recently have simulations quality water came to be recognized on the national scene as a important tool for assessing the quality of the product carried across the network. Simulations of hypothetical cases were carried out relying on the conditions: multi-source chlorine decay; oxidation, mass transfer, and adsorption of arsenic; bacterial regrowth with chlorine inhibition; and chloramine decomposition. A detailed analysis of these programs and application (in studies of cases) (of such study cases developed) in this essay, aimed to contribute to enlarge knowledge about the problems of computer modeling quality of water supply systems and water distribution / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O consumo de águas com alto teor de flúor pode resultar em fluorose dental ou esquelética, além de outros malefícios para a saúde pública. Neste sentido, o presente trabalho avaliou o processo de redução de flúor contido em excesso em água sintética e subterrânea fluorada a partir do processo de coagulação/floculação/sedimentação (C/F/S) com extrato aquoso de Moringa oleifera Lam e, do processo combinado com filtração por membranas. Os ensaios de C/F/S foram realizados em equipamento “jar test”, sendo a Moringa, utilizada na forma de extrato aquoso em diferentes concentrações. As amostras de água sintética e subterrânea foram fluoradas com fluoreto de sódio (NaF) nas concentrações de 3,0; 5,0; 7,5 e 10,0 mg F-/L e, variando-se o pH entre 3, 7 e 9. Os ensaios combinados com membranas de microfiltração e ultrafiltração, utilizando-se pressões de 1 e 2 bar, consistiram em submeter amostras de água sintética fluorada na concentração inicial de 5,0 mg F-/L, concentração de Moringa de 5 g/L e, pH7 ao processo de C/F/S, seguido da passagem pelo módulo de micro-ultrafiltração. O monitoramento do sistema de tratamento proposto, foi verificado por meio das análises de cor aparente, turbidez, pH, condutividade e flúor, antes e após os ensaios. Os resultados demonstraram bons valores de eficiência para o tratamento proposto de C/F/S, sendo que, para a concentração inicial de flúor de 3,0 mg F-/L todos os residuais de flúor tanto para a água sintética como para a água subterrânea fluorada, ficaram abaixo do valor máximo estabelecido pela Portaria nº 2.914/2011 do Ministério da Saúde que estabelece o limite de 1,5 mg F-/L. Os demais residuais provenientes das concentrações de 5,0; 7,5 e 10,0 mg F-/L, ficaram ligeiramente acima da legislação. Os valores de pH final ficaram dentro da faixa de neutralidade. Em relação aos parâmetros cor, turbidez e condutividade final, houve um ligeiro aumento dos valores, sendo indicado uma posterior etapa de pós-tratamento, como a adoção de filtração. Para o processo combinado, obteve-se bons resultados de redução de flúor, cor e turbidez da ordem de 83,0 %, 96,0 % e 98,0 %, respectivamente, para a membrana de 5 kDa utilizando pressão de 2 bar. De modo geral, os processos de tratamento propostos utilizando extrato de sementes de Moringa oleifera Lam, demonstraram-se como uma boa alternativa para a redução do excesso de flúor em águas, tendo-se em vista a utilização de um agente coagulante natural, biodegradável e responsável pela geração de um menor volume de lodo, diferentemente do que é observado com a utilização de coagulantes químicos. / The consumption of water with high fluoride levels may result in dental or skeletal fluorosis, and other hazards to public health. In this sense, the present study evaluated the process of reducing excess fluoride contained in fluoridated synthetic water and groundwater from the coagulation/ flocculation/sedimentation (C/F/S) with aqueous extract of Moringa oleifera Lam, and the process combined with membrane filtration. Assays C/F/S were performed in "jar test", and Moringa, used in the aqueous extract at different concentrations. Water samples were fluorinated and ground synthetic sodium fluoride (NaF) at concentrations of 3.0, 5.0, 7.5 and 10.0 mg F-/L, varying the pH between 3, 7 and 9. Tests combined with microfiltration and ultrafiltration membranes, using pressures of 1 bar and 2, consisting in subjecting samples of fluorinated synthetic water initial concentration of 5.0 mg F-/L, Moringa concentration of 5 g/L and , pH7 to process C/F/S, followed by passage through micro-ultrafiltration module. The monitoring system proposed treatment was assessed through analyzes of apparent color, turbidity, pH, conductivity and fluoride before and after the tests. The results showed good efficiency values proposed for the treatment of C/F/S, and so the initial concentration of 3.0 mg/L of fluoride all residual to both the synthetic water as the water Fluorinated underground, were below the maximum established by Ordinance nº 2.914/2011 the Ministry of Health establishing the limit of 1.5 mg F-/L. The remaining residual concentration of from 5.0: 7.5 and 10.0 mg F-/L, were slightly above the law. The final pH values were within the range of neutrality. The parameters color, turbidity and conductivity end there was a slight increase in values, and a subsequent step indicated post-treatment such as the adoption of filtration. To the combined process, good results were obtained reduction fluorine, color and turbidity of the order of 83.0%, 96.0% and 98.0% respectively for the 5 kDa membrane using pressure of 2 bar. Generally, treatment processes proposed using seed extract Moringa oleifera Lam, proved to be a good alternative to the reduction of excess of fluorine in water, with a view to the use of a coagulating agent natural, biodegradable and the generation of smaller volumes of sludge, unlike what is observed with the use of chemical coagulants.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O consumo de águas com alto teor de flúor pode resultar em fluorose dental ou esquelética, além de outros malefícios para a saúde pública. Neste sentido, o presente trabalho avaliou o processo de redução de flúor contido em excesso em água sintética e subterrânea fluorada a partir do processo de coagulação/floculação/sedimentação (C/F/S) com extrato aquoso de Moringa oleifera Lam e, do processo combinado com filtração por membranas. Os ensaios de C/F/S foram realizados em equipamento “jar test”, sendo a Moringa, utilizada na forma de extrato aquoso em diferentes concentrações. As amostras de água sintética e subterrânea foram fluoradas com fluoreto de sódio (NaF) nas concentrações de 3,0; 5,0; 7,5 e 10,0 mg F-/L e, variando-se o pH entre 3, 7 e 9. Os ensaios combinados com membranas de microfiltração e ultrafiltração, utilizando-se pressões de 1 e 2 bar, consistiram em submeter amostras de água sintética fluorada na concentração inicial de 5,0 mg F-/L, concentração de Moringa de 5 g/L e, pH7 ao processo de C/F/S, seguido da passagem pelo módulo de micro-ultrafiltração. O monitoramento do sistema de tratamento proposto, foi verificado por meio das análises de cor aparente, turbidez, pH, condutividade e flúor, antes e após os ensaios. Os resultados demonstraram bons valores de eficiência para o tratamento proposto de C/F/S, sendo que, para a concentração inicial de flúor de 3,0 mg F-/L todos os residuais de flúor tanto para a água sintética como para a água subterrânea fluorada, ficaram abaixo do valor máximo estabelecido pela Portaria nº 2.914/2011 do Ministério da Saúde que estabelece o limite de 1,5 mg F-/L. Os demais residuais provenientes das concentrações de 5,0; 7,5 e 10,0 mg F-/L, ficaram ligeiramente acima da legislação. Os valores de pH final ficaram dentro da faixa de neutralidade. Em relação aos parâmetros cor, turbidez e condutividade final, houve um ligeiro aumento dos valores, sendo indicado uma posterior etapa de pós-tratamento, como a adoção de filtração. Para o processo combinado, obteve-se bons resultados de redução de flúor, cor e turbidez da ordem de 83,0 %, 96,0 % e 98,0 %, respectivamente, para a membrana de 5 kDa utilizando pressão de 2 bar. De modo geral, os processos de tratamento propostos utilizando extrato de sementes de Moringa oleifera Lam, demonstraram-se como uma boa alternativa para a redução do excesso de flúor em águas, tendo-se em vista a utilização de um agente coagulante natural, biodegradável e responsável pela geração de um menor volume de lodo, diferentemente do que é observado com a utilização de coagulantes químicos. / The consumption of water with high fluoride levels may result in dental or skeletal fluorosis, and other hazards to public health. In this sense, the present study evaluated the process of reducing excess fluoride contained in fluoridated synthetic water and groundwater from the coagulation/ flocculation/sedimentation (C/F/S) with aqueous extract of Moringa oleifera Lam, and the process combined with membrane filtration. Assays C/F/S were performed in "jar test", and Moringa, used in the aqueous extract at different concentrations. Water samples were fluorinated and ground synthetic sodium fluoride (NaF) at concentrations of 3.0, 5.0, 7.5 and 10.0 mg F-/L, varying the pH between 3, 7 and 9. Tests combined with microfiltration and ultrafiltration membranes, using pressures of 1 bar and 2, consisting in subjecting samples of fluorinated synthetic water initial concentration of 5.0 mg F-/L, Moringa concentration of 5 g/L and , pH7 to process C/F/S, followed by passage through micro-ultrafiltration module. The monitoring system proposed treatment was assessed through analyzes of apparent color, turbidity, pH, conductivity and fluoride before and after the tests. The results showed good efficiency values proposed for the treatment of C/F/S, and so the initial concentration of 3.0 mg/L of fluoride all residual to both the synthetic water as the water Fluorinated underground, were below the maximum established by Ordinance nº 2.914/2011 the Ministry of Health establishing the limit of 1.5 mg F-/L. The remaining residual concentration of from 5.0: 7.5 and 10.0 mg F-/L, were slightly above the law. The final pH values were within the range of neutrality. The parameters color, turbidity and conductivity end there was a slight increase in values, and a subsequent step indicated post-treatment such as the adoption of filtration. To the combined process, good results were obtained reduction fluorine, color and turbidity of the order of 83.0%, 96.0% and 98.0% respectively for the 5 kDa membrane using pressure of 2 bar. Generally, treatment processes proposed using seed extract Moringa oleifera Lam, proved to be a good alternative to the reduction of excess of fluorine in water, with a view to the use of a coagulating agent natural, biodegradable and the generation of smaller volumes of sludge, unlike what is observed with the use of chemical coagulants.

Orientador: José Teixeira Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-16T21:13:37Z (GMT). No. of bitstreams: 1 Piedade_AlineRegina_D.pdf: 10351385 bytes, checksum: 593830ddbd99d3342ee3c371badce31f (MD5) Previous issue date: 2010 / Resumo: O uso de leitos cultivados é uma alternativa no tratamento de águas residuárias, pois atuam na depuração de efluentes. Um aspecto importante deste tema está associado à complexidade ecossistêmica dos leitos. Com base neste enfoque, objetivou-se neste trabalho avaliar a dinâmica da retenção/remoção de fósforo em três sistemas de fluxo subsuperficial, com leitos cultivados por Typha sp. sob suporte de brita, o qual atuou no pós-tratamento de efluentes de esgoto doméstico de Reatores Anaeróbios Compartimentados (RAC). Para a determinação de critérios de projetos, houve o monitoramento da quantidade de água (vazão, volume, TDH e evaporação/evapotranspiração), da qualidade de água (concentração, carga e eficiência de retenção/remoção de fósforo), bem como dos levantamentos fisiológicos da vegetação e meteorológicos do local. Os leitos cultivados com a macrófita Typha sp. (leito Typha 1 e leito Typha 2) apresentaram eficiências de retenção de fósforo superiores ao leito no qual continha apenas brita (leito Brita). Em relação aos leitos cultivados com a macrófita, as vazões médias de entrada/saída foram de 55,4 e 51,2 l h-1, respectivamente, com taxa de evapotranspiração média de 8,9 mm. O TDH médio foi de 1,99 dias. As concentrações médias de fósforo de entrada/saída foram de 4,0 e 3,3 mg l-1, respectivamente. A carga média de fósforo de entrada foi de 226,3 mg h-1 e a carga média de saída foi de 175,6 mg h-1. A eficiência média de retenção de fósforo total foi de 22,4% e a eficiência média de remoção pela Typha sp. foi de 10,6%. Quanto ao desenvolvimento da vegetação, foram obtidas médias de 407 plantas e altura de 173,2 cm, sendo que cada planta tinha, em média, 11 folhas e área foliar de, aproximadamente, 0,27 m2. A vegetação apresentou massa de matéria fresca de 35,8 kg e massa de matéria seca de 6,4 kg, totalizando 17,8% de matéria seca. A concentração média de fósforo total na parte aérea das plantas foi de 2,5 g kg-1, que representou uma quantidade de 16,2 g de fósforo. Em relação às variáveis meteorológicas, notou-se grande influência do Déficit de Pressão de Vapor Saturado (DPVS) na demanda de evapotranspiração das plantas. Conclui-se que os sistemas de leitos cultivados com Typha sp. têm potencialidade de aplicação para tratamento de efluentes de esgoto doméstico / Abstract: Constructed wetlands are important alternatives for polluted water treatment because they carry the secondary treatment of effluents in the purification process. The characteristic ecosystem complexity of the wetlands is an important issue in this subject matter. Based on that consideration, the objective of this research work was established in evaluating phosphorus retention in three subsurface flow systems in constructed wetlands, using gravel medium (substrate) cultivated with macrophyte Typha sp., which acts as post-treatment domestic effluents of anaerobic baffled reactor (ABR). In order to establish criteria for projects, wetlands monitoring included flow recording, transpiration, water quantity (flow, evaporation/evapotranspiration and TDH), water quality (concentration, load and phosphorous retention efficiency) as well as surveys of physiological vegetation and meteorological site. Results indicated the constructed wetlands with the macrophyta Typha sp. (Typha be 1 and Typha 2) presented higher phosphorous retention efficiency if compared with gravel bed. Results also showed an average water input flow of 55.4 l h-1 and an output water flow of 51.2 l h-1 yielding a balance of 4.2 l h-1 which represents an average evapotranspiration rate of 8.9 mm. Average TDH was noted to be of 1.99 days. Inlet water showed an average phosphorous concentration of 4.0 mg l-1 meanwhile the outlet water presented of 3.3 mg l-1 holding a difference of 0.7 mg l-1. Average phosphorous concentration of inlet water was recorded as 226.3 mg h-1 meanwhile the average phosphorous concentration at the outlet water was of 175.6 mg h-1, holding a difference of 50.8 mg h-1. Average phosphorous total retention efficiency was of 22.4% and of 10.6% of remotion by Typha sp. Vegetation development indicated na average value of 173.2 cm measured in 407 individuals, observing that an average number of 11 leaves for each plant and a foliar area close to 0.27 m2. Total vegetation presented 35.8 kg of fresh mass and 6.4 kg of dry mass, representing 17.8% of dry matter. Average phosphorous total concentration in the aerial part was of 2.5 g kg-1 corresponding to a total value of 16.2 g. Among the metheorological variables associated to the physiological vegetative development, the variable named DPVS was noted to exhibit major influence on the plant evapotranspiration demand. It can be concluded that constructed wetlands with Typha sp. showed potential application in the wastewater treatment of domestic sewage / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Nesta dissertação é apresentada a avaliação da dispersão de contaminantes no Rio São Pedro, pequeno curso situado na Bacia Hidrográfica do Rio Macaé, centro-norte do Estado do Rio de Janeiro. Para tanto, utilizou-se uma abordagem que conjugou simulação e observação. A simulação compreendeu a modelagem do transporte de substância conservativa em um dado trecho desse rio. O modelo adotado utilizou a formulação unidimensional da equação de advecção-dispersão, que tem como parâmetro crítico o coeficiente de dispersão longitudinal. Paralelamente foi conduzido um experimento de campo, que constou da injeção instantânea de massa conhecida de sal nesse trecho do rio, tendo sido monitorada a concentração resultante em uma seção situada a jusante do ponto de lançamento. Códigos numéricos foram implementados para obter-se o melhor ajuste entre simulação e observação, ajuste esse obtido através da estimativa do coeficiente de dispersão. / In this dissertation we performed an assessment of contaminat dispersion in a small river located at Macaé Watershed Basin. We adopted an approach that made use both of simulation and experiments. The simulation solved the one dimensional transport model for a conservative substance, on which the dispersion coefficient plays a critical role. The observation data was obtained in an experiment especially designed for this purpose. An instantaneous injection of a known quantity of mass of salt in a given position of the river was discharged and the resulting concentration was monitored in two downstream stations. Numerical codes were built in order to obtain a better fitting between simulation and observation.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Nesta dissertação é apresentada a avaliação da dispersão de contaminantes no Rio São Pedro, pequeno curso situado na Bacia Hidrográfica do Rio Macaé, centro-norte do Estado do Rio de Janeiro. Para tanto, utilizou-se uma abordagem que conjugou simulação e observação. A simulação compreendeu a modelagem do transporte de substância conservativa em um dado trecho desse rio. O modelo adotado utilizou a formulação unidimensional da equação de advecção-dispersão, que tem como parâmetro crítico o coeficiente de dispersão longitudinal. Paralelamente foi conduzido um experimento de campo, que constou da injeção instantânea de massa conhecida de sal nesse trecho do rio, tendo sido monitorada a concentração resultante em uma seção situada a jusante do ponto de lançamento. Códigos numéricos foram implementados para obter-se o melhor ajuste entre simulação e observação, ajuste esse obtido através da estimativa do coeficiente de dispersão. / In this dissertation we performed an assessment of contaminat dispersion in a small river located at Macaé Watershed Basin. We adopted an approach that made use both of simulation and experiments. The simulation solved the one dimensional transport model for a conservative substance, on which the dispersion coefficient plays a critical role. The observation data was obtained in an experiment especially designed for this purpose. An instantaneous injection of a known quantity of mass of salt in a given position of the river was discharged and the resulting concentration was monitored in two downstream stations. Numerical codes were built in order to obtain a better fitting between simulation and observation.

Waste Load Allocation (WLA) in rivers refers to the determination of required pollutant fractional removal levels at a set of point sources of pollution to ensure that water quality standards are maintained throughout the system. Optimal waste load allocation implies that the selected pollution treatment vector not only maintains the water quality standards, but also results in the best value for the objective function defined for the management problem. Waste load allocation problems are characterized by uncertainties due to the randomness and imprecision. Uncertainty due to randomness arises mainly due to the random nature of the variables influencing the water quality. Uncertainty due to imprecision or fuzziness is associated with setting up the water quality standards and goals of the Pollution Control Agencies (PCA), and the dischargers (e.g., industries and municipal dischargers). Many decision problems in water resources applications are dominated by natural, extreme, rarely occurring, uncertain events. However usually such events will be absent or be rarely present in the historical records. Due to the scarcity of information of these uncertain events, a realistic decision-making becomes difficult. Furthermore, water resources planners often deal with imprecision, mostly due to imperfect knowledge and insufficient or inadequate data. Therefore missing data is very common in most water resources decision problems. Missing data introduces inaccuracy in analysis and evaluation. For instance, the sample mean of the available data can be an inaccurate estimate of the mean of the complete data. Use of sample statistics estimated from inadequate samples in WLA models would lead to incorrect decisions. Therefore there is a necessity to incorporate the uncertainty due to missing data also in WLA models in addition to the uncertainties due to randomness and imprecision. The uncertainty in the input parameters due to missing or inadequate data renders the input parameters (such as mean and variance) as interval grey parameters in water quality decision-making. In a Fuzzy Waste Load Allocation Model (FWLAM), randomness and imprecision both can be addressed simultaneously by using the concept of fuzzy risk of low water quality (Mujumdar and Sasikumar, 2002). In the present work, an attempt is made to also address uncertainty due to partial ignorance due to missing data or inadequate data in the samples of input variables in FWLAM, considering the fuzzy risk approach proposed by Mujumdar and Sasikumar (2002). To address the uncertainty due to missing data or inadequate data, the input parameters (such as mean and variance) are considered as interval grey numbers. The resulting output water quality indicator (such as DO) will also, consequently, be an interval grey number. The fuzzy risk will also be interval grey number when output water quality indicator is an interval grey number. A methodology is developed for the computation of grey fuzzy risk of low water quality, when the input variables are characterized by uncertainty due to partial ignorance resulting from missing or inadequate data in the samples of input variables. To achieve this, an Imprecise Fuzzy Waste Load Allocation Model (IFWLAM) is developed for water quality management of a river system to address uncertainties due to randomness, fuzziness and also due to missing data or inadequate data. Monte Carlo Simulation (MCS) incorporating a water quality simulation model is performed two times for each set of randomly generated input variables: once for obtaining the upper bound of DO and once for the lower bound of DO, by using appropriate upper or lower bounds of interval grey input variables. These two bounds of DO are used in the estimation of grey fuzzy risk by substituting the upper and lower values of fuzzy membership functions of low water quality. A backward finite difference scheme (Chapra, 1997) is used to solve the water quality simulation model. The goal of PCA is to minimize the bounds of grey fuzzy risk, whereas the goal of dischargers is to minimize the fractional removal levels. The two sets of goals are conflicting with each other. Fuzzy multiobjective optimization technique is used to formulate the multiobjective model to provide best compromise solutions. Probabilistic Global Search Lausanne (PGSL) method is used to solve the optimization problem. Finally the results of the model are compared with the results of risk minimization model (Ghosh and Mujumdar, 2006), when the methodology is applied to the case study of the Tunga-Bhadra river system in South India. The model is capable of determining a grey fuzzy risk with the corresponding bounds of DO, at each check point, rather than specifying a single value of fuzzy risk as done in a Fuzzy Waste Load Allocation Model (FWLAM). The IFWLAM developed is based on fuzzy multiobjective optimization problem with ‘max-min’ as the operator, which usually may not result in a unique solution and there exists a possibility of obtaining multiple solutions (Karmakar and Mujumdar, 2006b). Karmakar and Mujumdar (2006b) developed a two-phase Grey Fuzzy Waste Load Allocation Model (two-phase GFWLAM), to determine the widest range of interval-valued optimal decision variables, resulting in the same value of interval-valued optimal goal fulfillment level as obtained from GFWLAM (Karmakar and Mujumdar 2006a). Following Karmakar and Mujumdar (2006b), two optimization models are developed in this study to capture all the decision alternatives or multiple solutions: one to maximize and the other to minimize the summation of membership functions of the dischargers by keeping the maximum goal fulfillment level same as that obtained in IFWLAM to obtain a lower limit and an upper limit of fractional removal levels respectively. The aim of the two optimization models is to obtain a range of fractional removal levels for the dischargers such that the resultant grey fuzzy risk will be within acceptable limits. Specification of a range for fractional removal levels enhances flexibility in decision-making. The models are applied to the case study of Tunga-Bhadra river system. A range of upper and lower limits of fractional removal levels is obtained for each discharger; within this range, the discharger can select the fractional removal level so that the resulting grey fuzzy risk will also be within specified bounds. In IFWLAM, the membership functions are subjective, and lower and upper bounds are arbitrarily fixed. Karmakar and Mujumdar (2006a) developed a Grey Fuzzy Waste Load Allocation Model (GFWLAM), in which uncertainty in the values of membership parameters is quantified by treating them as interval grey numbers. Imprecise membership functions are assigned for the goals of PCA and dischargers. Following Karmakar and Mujumdar (2006a), a Grey Optimization Model with Grey Fuzzy Risk is developed in the present study to address the uncertainty in the memebership functions of IFWLAM. The goals of PCA and dischargers are considered as grey fuzzy goals with imprecise membership functions. Imprecise membership functions are assigned to the fuzzy set of low water quality and fuzzy set of low risk. The grey fuzzy risk approach is included to account for the uncertainty due to missing data or inadequate data in the samples of input variables as done in IFWLAM. Randomness and imprecision associated with various water quality influencing variables and parameters of the river system are considered through a Monte-Carlo simulation when input parameters (such as mean and variance) are interval grey numbers. The model application is demonstrated with the case study of Tunga-Bhadra river system in South India. Finally the results of the model are compared with the results of GFWLAM (Karmakar and Mujumdar, 2006a). For the case study of Tunga Bhadra River system, it is observed that the fractional removal levels are higher for Grey Optimization Model with Grey Fuzzy Risk compared to GFWLAM (Karmakar and Mujumdar, 2006a) and therefore the resulting risk values at each check point are reduced to a significant extent. The models give a set of flexible policies (range of fractional removal levels). Corresponding optimal values of goal fulfillment level and the grey fuzzy risk are all in terms of interval grey numbers. The IFWLAM and Grey Fuzzy Optimization Model with Grey Fuzzy Risk, developed in the study do not limit their application to any particular pollutant or water quality indicator in the river system. Given appropriate transfer functions for spatial distribution of the pollutants in water body, the models can be used for water quality management of any general river system.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / High nitrates in drinking water are significant in relation to an infant disease, methemoglobinemia, and the U.S. public health service has set a limit of 45 ppm for human consumption. This paper illustrates how chemical hydrographs were used in a study of nitrates in the groundwater of the Fresno-Clovis metropolitan area (F.C.M.A.) of semiarid central California. The area comprises about 145 square miles, with a population of 310,000. Urban water use is entirely derived from wells, whereas the surrounding agriculture relies on surface and ground water. In 1965, the California department of water resources noted nitrate concentrations in the F.C.M.A. were exceeding the safe limit. A number of sources of error in chemical analyses of water quality are noted. A measure of the accuracies of analyses and a method of double-checking anomalous results is furnished by plotting chemical hydrographs of individual wells. Seasonal changes in nitrate were consistent for many parts of the area, and were related to hydrogeologic factors and parameters directly affecting nitrification. Nitrate hydrographs were monitored by chloride hydrographs. The highest nitrate concentrations were in the shallower parts of the aquifer, and well deepening and changes in water level, pumping patterns and recharge rates complicated interpretations. However, the hydrographs helped to pinpoint the source of nitrate in areas where several possible sources were present.