Este trabalho apresenta a caracterização geoambiental de solos de uma área contaminada, localizada no município de Santo André, Estado de São Paulo, Brasil. O objetivo foi determinar parâmetros experimentais para permitir o estudo de alguns aspectos do transporte do pesticida organoclorado Hexaclorociclohexano (HCH). A área de estudo contém células com cerca de 30.000 toneladas de um material contendo HCH em elevadas concentrações. As investigações de campo demonstram que há concentrações de HCH na água subterrânea. Em 2011, foram coletadas amostras deformadas e indeformadas de solo em quatro diferentes pontos superficiais da área contaminada, e posteriormente uma amostra composta da camada de solo de alteração de rocha (SAR), a fim de responder a questionamentos quanto à mobilidade do contaminante na área. A caracterização geoambiental, baseada em ensaios laboratoriais, foi realizada por meio das seguintes análises: análise granulométrica, limites de Atterberg, densidade específica, porosidade, umidade do solo, curva de retenção de água no solo, condutividade hidráulica, ensaio de adsorção, pH, condutividade elétrica, capacidade de troca catiônica (CTC), teor de matéria orgânica e teor de voláteis. O solo superficial da área é heterogêneo e a capacidade de adsorção dos solos analisados foi menor do que o esperado. Esta caracterização subsidiou o estudo de fluxo e transporte do HCH, por meio de simulação numérica, utilizando o programa Hydrus 1D. As simulações tiveram dois objetivos diferentes: no primeiro foi avaliado os resultados da simulação em comparação à situação atual no campo; no segundo foi avaliada a sensibilidade do transporte em função da alteração dos parâmetros obtidos experimentalmente Ks; Kd; s e (Van Genuchten); e dos parâmetros obtidos na literatura. Os resultados permitiram concluir que o modelo Hydrus 1D consegue representar a contaminação do HCH no solo. O parâmetro de degradação na água foi essencial para chegar em ordens de grandeza de concentrações próximas das identificadas em campo. Os parâmetros de degradação, difusividade, dispersividade e condutividade hidráulica são os que mais afetam os resultados finais de concentração do HCH na água subterrânea e, portanto, merecem atenção maior durante as futuras investigações. / This paper presents the geoenvironmental characterization of soils from a contaminated site, located in Santo André, São Paulo State, Brazil. The objective was to determine experimental parameters to allow the study of some aspects of transport of the organochlorine pesticide hexachlorocyclohexane (HCH). The study site contains trenches with about 30,000 tons of a material containing high concentrations of HCH. The site investigations show that there are HCH concentrations in groundwater. In 2011, disturbed and undisturbed soil samples were collected at four different surface points of the contaminated site, and then a sample of soil from rock alteration layer (SAR) was also composed for characterization in order to answer questions concerning the mobility of contaminant in the site. The environmental characterization based on laboratory tests, was performed by the following analyzes: grain size distribution, Atterberg limits, specific gravity, porosity, moisture content, water retention curve, hydraulic conductivity, pH, electrical conductivity, cation exchange capacity (CEC), organic matter content and volatile content. The surface soil of the area is heterogeneous and the adsorption capacity of the soils analyzed were lower than expected. This characterization allowed the study of flow and transport of HCH through numerical simulation using the Hydrus 1D software. The simulations had two different goals, the first was evaluated the simulation results compared to the current situation in the field. In a second step the sensitivity of transport due to the change of the parameters obtained experimentally Ks; Kd; s and (Van Genuchten); and parameters obtained from the literature. The results showed that the Hydrus 1D model simulates HCH contamination in soil. Water degradation parameter was essential to get orders of magnitude similar to those identified in field concentrations. The degradation, diffusivity, hydraulic conductivity and dispersivity parameters are those that most affect the final results of concentration of HCH in groundwater and therefore deserve more attention in future investigations.

No description available.

Cypress Creek is an urbanizing watershed in the Gulf Coast region of Texas that contributes the largest inflow of urban runoff containing suspended solids to Lake Houston, the primary source of drinking water for the City of Houston. Historical water quality data was statistically analyzed to characterize the watershed and its pollutant sources. It was determined that the current sampling program provides limited information on the complex behaviors of pollutant sources in both dry weather and rainfall events. In order to further investigate the dynamics of pollutant export from Cypress Creek to Lake Houston, fully distributed hydrologic and water quality models were developed and employed to simulate high frequency small storms. A fully distributed hydrologic model, Vflo(TM) , was used to model streamflow during small storm events in Cypress Creek. Accurately modeling small rainfall events, which have traditionally been difficult to model, is necessary for investigation and design of watershed management since small storms occur more frequently. An assessment of the model for multiple storms shows that using radar rainfall input produces results well matched to the observed streamflow for both volume and peak streamflow. Building on the accuracy and utility of distributed hydrologic modeling, a water quality model was developed to simulate buildup, washoff, and advective transport of a conservative pollutant. Coupled with the physically based Vflo(TM) hydrologic model, the pollutant transport model was used to simulate the washoff and transport of total suspended solids for multiple small storm events in Cypress Creek Watershed. The output of this distributed buildup and washoff model was compared to storm water quality sampling in order to assess the performance of the model and to further temporally and spatially characterize the storm events. This effort was the first step towards developing a fully distributed water quality model that can be widely applied to a wide variety of watersheds. It provides the framework for future incorporation of more sophisticated pollutant dynamics and spatially explicit evaluation of best management practices and land use dynamics. This provides an important tool and decision aid for watershed and resource management and thus efficient protection of the sources waters.

No description available.

Esta dissertação de mestrado tem como objetivo principal avaliar o transporte de poluentes de um lixiviado real de aterro sanitário em um solo laterítico do estado de São Paulo. A pesquisa objetiva também comparar dois métodos de avaliação de transporte de poluentes: ensaios laboratoriais e análise de dados de contaminação de campo. No aterro sanitário de Botucatu houve, comprovadamente, percolação do lixiviado pelo subsolo durante aproximadamente 15 anos, sob uma lagoa de acumulação de lixiviado sem revestimento de fundo. Foram coletadas amostras de solo subjacente à lagoa, uma areia argilosa, em três perfis verticais na superfície e nas profundidades de 0,25 m, 0,50 m, 1,00 m, 2,00 m e 4,00 m. Os poluentes investigados foram: arsênio, cádmio, carbono orgânico total (COT), chumbo, cloreto, cobre, cromo, ferro, manganês, níquel, nitrogênio Kjeldahl total (NKT) e zinco. Amostras indeformadas do solo local não contaminado foram também coletadas para ensaios de permeabilidade à água e ao lixiviado, assim como para ensaios de coluna. A condutividade hidráulica do solo é da ordem de 10-6 m/s, porém significativamente influenciada pelo gradiente hidráulico aplicado e pela duração da percolação. A condutividade hidráulica diminuiu com a percolação de lixiviado para ordens de grandeza entre 10-8 e 10-6 m/s, dependendo do gradiente hidráulico. Os ensaios de coluna mostraram concentrações efluentes dos elementos pesquisados superiores às afluentes, impossibilitando a obtenção de parâmetros de transporte de poluentes. A análise das amostras contaminadas coletadas in situ mostrou que, embora o solo local seja poroso e apresente alta permeabilidade, as concentrações dos elementos estudados eram inferiores aos limites legais de contaminação do órgão de controle ambiental estadual. O cloreto e o nitrogênio, para os quais não há limites legais, apresentaram-se no subsolo em concentrações elevadas, superiores às concentrações no solo natural e, em algumas amostras, às do lodo depositado no fundo da lagoa. / The aim of this research is to evaluate transport of pollutants from a sanitary landfill leachate through a Brazilian lateritic soil by two methods: laboratory tests and analysis of field contamination. In Botucatu Sanitary Landfill, leachate stored in an unlined pond infiltrated into the subsoil for 15 years. Samples of the subjacent soil, a porous clayey sand, were collected in three profiles located inside the area of the leachate pond at the following depths: surface, 0.25 m, 0.50 m, 1.00 m, 2.00 m and 4.00 m. The investigated pollutants were arsenic, cadmium, chloride, cooper, iron, lead, manganese, nickel, Kjeldahl nitrogen, total organic carbon (TOC) and zinc. The hydraulic conductivity measured in undisturbed and uncontaminated samples of the local soil, around 10-6 m/s, is significantly influenced by the applied hydraulic gradient and the percolation duration. When leachate substituted water as percolation fluid, the hydraulic conductivity decreased to values between 10-8 and 10-6 m/s depending on the hydraulic gradient. Chemical analysis of contaminated samples showed that concentrations of the researched elements in the subsoil were lower than legal maximum contamination limits established by the environmental agency of São Paulo state, in spite of the fact that the local soil is porous and has high hydraulic conductivity. On the other hand, chloride and Kjeldahl nitrogen, pollutants for which there are no legal limits, were found in concentrations much higher than background values, and in some samples even higher than those measured in the leachate sludge deposited in the bottom of the storage pond.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O estudo da qualidade de Ãgua em corpos hÃdricos, atravÃs de modelagem matemÃtica, tem se tornado um importante caminho no controle e conservaÃÃo dos recursos hÃdricos. Nos dias presentes, com o significativo avanÃo na Ãrea computacional, com computadores de alta velocidade, tem sido possÃvel representar um processo fÃsico qualquer, atravÃs de um modelo matemÃtico com um maior nÃvel de complexidade. Neste sentido, os processos de transporte de poluentes, em rios, estuÃrios ou reservatÃrios tÃm sido representados de forma mais realista, com a ajuda de formulaÃÃes matemÃticas. Por outro lado, a grande parte dos modelos matemÃticos disponÃveis na literatura, dà um tratamento determinÃstico aos estudos de processos fÃsicos. Neste caso, qualquer estudo que necessite de avaliar incerteza ou risco em engenharia, nÃo conseguirà atingir seus objetivos sem um tratamento estocÃstico em suas formulaÃÃes matemÃtica. Este trabalho estuda a aplicaÃÃo da Teoria Fuzzy nos modelos de transporte de poluente para estudar o comportamento das concentraÃÃes de poluentes em rios naturais, atravÃs de funÃÃes de pertinÃncias. O estudo desenvolve uma metodologia, com base nos modelos de transporte fuzzy, e aplica esta metodologia em alguns rios com dados disponÃveis na literatura. Finalmente, o estudo avalia a capacidade desta teoria predizer e avaliar campos de risco fuzzy nestes corpos dâÃgua, mostrando, assim, seu comportamento, no tempo e ao longo do trecho do rio estudado. Os resultados mostram que os modelos fuzzys, aplicados aos processos de transporte de poluentes, podem ser uma boa alternativa na determinaÃÃo do risco de degradaÃÃo de um sistema hÃdrico qualquer. / The study of the water quality in bodies of water, through mathematical modeling has become an important way in the control and conservation of the water resources systems. In the present days, with the significant progress in the computational area, with high-speed computers, it has been possible to represent any physical process, through a mathematical model, with a larger complexity level. In this sense, the transport processes of pollutant, in rivers, estuaries or reservoirs, have been represented in a more realistic way, with the mathematical formulations. On the other hand, the great part of the available mathematical models, in the literature, gives a deterministic treatment to the studies of physical processes. In this case, any study that needs to evaluate uncertainty or engineering risk, it will not get to reach their objectives, without a stochastic treatment in their mathematics formulations. This work studies applications of the Fuzzy Theory in the transport models of pollutant to study the behavior of the concentrations of pollutant in natural rivers, through membership functions. The study develops a methodology, with base in the models of transport fuzzy and it applies this methodology in some rivers with available data. Finally, the study evaluates the capacity of this theory to predict and to calculate fields of risk fuzzy in these bodies of water, showing, like this, its behavior, in the time and along the river. The results show that the fuzzy models, applied to the pollutant transport processes, can be an alternative in the determination of the risk of degradation of any water system.

Esta dissertação de mestrado tem como objetivo principal avaliar o transporte de poluentes de um lixiviado real de aterro sanitário em um solo laterítico do estado de São Paulo. A pesquisa objetiva também comparar dois métodos de avaliação de transporte de poluentes: ensaios laboratoriais e análise de dados de contaminação de campo. No aterro sanitário de Botucatu houve, comprovadamente, percolação do lixiviado pelo subsolo durante aproximadamente 15 anos, sob uma lagoa de acumulação de lixiviado sem revestimento de fundo. Foram coletadas amostras de solo subjacente à lagoa, uma areia argilosa, em três perfis verticais na superfície e nas profundidades de 0,25 m, 0,50 m, 1,00 m, 2,00 m e 4,00 m. Os poluentes investigados foram: arsênio, cádmio, carbono orgânico total (COT), chumbo, cloreto, cobre, cromo, ferro, manganês, níquel, nitrogênio Kjeldahl total (NKT) e zinco. Amostras indeformadas do solo local não contaminado foram também coletadas para ensaios de permeabilidade à água e ao lixiviado, assim como para ensaios de coluna. A condutividade hidráulica do solo é da ordem de 10-6 m/s, porém significativamente influenciada pelo gradiente hidráulico aplicado e pela duração da percolação. A condutividade hidráulica diminuiu com a percolação de lixiviado para ordens de grandeza entre 10-8 e 10-6 m/s, dependendo do gradiente hidráulico. Os ensaios de coluna mostraram concentrações efluentes dos elementos pesquisados superiores às afluentes, impossibilitando a obtenção de parâmetros de transporte de poluentes. A análise das amostras contaminadas coletadas in situ mostrou que, embora o solo local seja poroso e apresente alta permeabilidade, as concentrações dos elementos estudados eram inferiores aos limites legais de contaminação do órgão de controle ambiental estadual. O cloreto e o nitrogênio, para os quais não há limites legais, apresentaram-se no subsolo em concentrações elevadas, superiores às concentrações no solo natural e, em algumas amostras, às do lodo depositado no fundo da lagoa. / The aim of this research is to evaluate transport of pollutants from a sanitary landfill leachate through a Brazilian lateritic soil by two methods: laboratory tests and analysis of field contamination. In Botucatu Sanitary Landfill, leachate stored in an unlined pond infiltrated into the subsoil for 15 years. Samples of the subjacent soil, a porous clayey sand, were collected in three profiles located inside the area of the leachate pond at the following depths: surface, 0.25 m, 0.50 m, 1.00 m, 2.00 m and 4.00 m. The investigated pollutants were arsenic, cadmium, chloride, cooper, iron, lead, manganese, nickel, Kjeldahl nitrogen, total organic carbon (TOC) and zinc. The hydraulic conductivity measured in undisturbed and uncontaminated samples of the local soil, around 10-6 m/s, is significantly influenced by the applied hydraulic gradient and the percolation duration. When leachate substituted water as percolation fluid, the hydraulic conductivity decreased to values between 10-8 and 10-6 m/s depending on the hydraulic gradient. Chemical analysis of contaminated samples showed that concentrations of the researched elements in the subsoil were lower than legal maximum contamination limits established by the environmental agency of São Paulo state, in spite of the fact that the local soil is porous and has high hydraulic conductivity. On the other hand, chloride and Kjeldahl nitrogen, pollutants for which there are no legal limits, were found in concentrations much higher than background values, and in some samples even higher than those measured in the leachate sludge deposited in the bottom of the storage pond.

Cette thèse a pour objectif la construction de schémas d’ordre élevé et peu diffusifs pour le transport d’un scalaire dans les écoulements à surface libre, en deux ou trois dimensions. On souhaite en particulier obtenir des schémas robustes, qui gardent au niveau discret les propriétés mathématiques de l’équation de transport avec une faible diffusion numérique, et les utiliser sur des cas industriels. Dans ce travail deux méthodes numériques sont envisagées : une méthode aux volumes finis (VF) et une méthode aux résidus distribués (RD). Dans les deux cas, l’équation de transport est résolue avec une approche découplée, qui est la solution la plus avantageuse en termes de précision et de coûts de calcul. Pour ce qui concerne la méthode aux volumes finis, les équations de Saint-Venant couplées à l’équation du transport sont d’abord résolues avec un schéma dit vertex-centred où le flux numérique est approximé avec un solveur de Riemann appelé Harten-Lax-Van Leer-Contact [135]. A partir de cette approche, une formulation découplée est proposée. Cette dernière permet de résoudre l’équation du transport avec un pas de temps plus grand que celui de la formulation couplée. Cette idée a été d’abord proposée pour d’autres schémas dans [13]. Pour augmenter l’ordre de précision en espace, la technique MUSCL [89] est utilisée en combinaison avec l’approche découplée. Finalement, la problématique des zones sèches est abordée. Dans le cas de la méthode aux résidus distribués, les équations de Saint-Venant sont résolues avec une méthode éléments finis, et la méthode RD est utilisée seulement pour discrétiser l’équation du transport, en focalisant l’attention sur les problèmes non stationnaires. L’équation de continuité du fluide discrétisée est employée pour garantir la conservation de la masse et le principe du maximum. Pour obtenir des schémas d’ordre deux dans les problèmes non stationnaires, un schéma prédicteur-correcteur [112] est utilisé, en l’adaptant au cas de concentration moyennée sur la verticale. Une version d’ordre 1 mais peu diffusive, est aussi présentée dans ce travail. De plus, un schéma localement implicite, complètement nouveau, est aussi formulé pour pouvoir traiter le problème des bancs découvrant. Les deux techniques sont validées d’abord sur des cas simples, pour évaluer l’ordre de précision des schémas et ensuite sur des cas plus complexes pour vérifier aussi les autres propriétés numériques. Les résultats montrent que les nouveaux schémas sont à la fois précis et conservatifs, tout en gardant la monotonie comme le prévoient les démonstrations. Un cas d’application industriel est aussi présenté en conclusion. Le schéma prédicteur-correcteur RD est adapté aussi au cas 3D, sans aucun problème théorique nouveau, par rapport au cas 2D. Les propriétés de base des schémas sont validées sur des cas test préliminaires / The purpose of this thesis is to build higher order and less diffusive schemes for pollutant transport in shallow water flows or 3D free surface flows. We want robust schemes which respect the main mathematical properties of the advection equation with relatively low numerical diffusion and apply them to environmental industrial applications. Two techniques are tested in this work: a classical finite volume method and a residual distribution technique combined with a finite element method. For both methods we propose a decoupled approach since it is the most advantageous in terms of accuracy and CPU time. Concerning the first technique, a vertex-centred finite volume method is used to solve the augmented shallow water system where the numerical flux is computed through an Harten-Lax-Van Leer-Contact Riemannsolver [135]. Starting from this solution, a decoupled approach is formulated and is preferred since it allows to compute with a larger time step the advection of a tracer. This idea was inspired by [13]. The Monotonic Upwind Scheme for Conservation Law [89], combined with the decoupled approach, is then used for the second order extension in space. The wetting and drying problem is also analysed and a possible solution is presented. In the second case, the shallow water system is entirely solved using the finite element technique and the residual distribution method is applied to the solution of the tracer equation, focusing on the case of time-dependent problems. However, for consistency reasons the resolution of the continuity equation must be considered in the numerical discretization of the tracer. In order to get second order schemes for unsteady cases a predictor-corrector scheme [112] is used in this work. A first order but less diffusive version of the predictor-corrector scheme is also introduced. Moreover, we also present a new locally semi-implicit version of the residual distribution method which, in addition to good properties in terms of accuracy and stability, has the advantage to cope with dry zones. The two methods are first validated on academical test cases with analytical solution in order to assess the order of the schemes. Then more complex cases are addressed to test the robustness of the schemes and their performance under different flow conditions. Finally a real test case for which real data are available is carried out. An extension of the predictor-corrector residual distribution schemes to the 3D case is presented as final contribution. Even in this case the RD technique is completely compatible with the finite element framework used for the Navier-Stokes equations, thus its extension to the 3D case does not present any extra theoretical problem. The method is tested on preliminary cases

<p>U okviru ovog rada je razvijen ravanski model koji sadrži sve važne aspekte interakcije vode, nanosa i zagađivača u prirodnim vodotocima. Model obuhvata procese<br />strujanja vode, oba oblika kretanja nanosa (suspendovani i vučeni), mehanizme<br />razmene mase između nanosa u suspenziji i nanosa u aktivnom sloju, deformacije korita usled erozije i deponovanja nanosnog materijala, mehanizme razmene<br />mase između nanosa u aktivnom sloju i aktivnom stratumu, kao i procese transporta nekonzervativne zagađuju&acute;ce materije koja je u interakciji sa nanosom preko<br />procesa adsorpcije/desorpcije. Formulisane jednačine transporta zagađivača obuhvataju njegovu pojavu u rastvorenom i adsorbovanom obliku. Razmena između<br />dva vida pojave zagađivača (rastvoreni i adsorbovani) je opisana preko kinetickih<br />procesa prvog reda, pri cemu je modelisanje koeficijenata razmene usko povezano<br />sa dostupnom povrˇsinom za adsorpciju. Sa druge strane, razmena između materije<br />adsorbovane na suspendovani nanos, odnosno materije adsorbovane na nanos u aktivnom sloju je neposredno vezana za nanosne procese uvlačenja zrna u suspenziju i<br />deponovanja istih iz suspenzije. Početni &scaron;ematski testovi su podrazumevali proveru<br />razvijenog algoritma za re&scaron;avanje advektivnih članova jednačina. Druga grupa &scaron;ematskih testova je podrazumevala implementaciju razvijenog modela transporta<br />zagađujuće materije, pri čemu su testirani i kvalitativno ocenjeni mehanizmi<br />razmene i interakcije. Za testiranje modela na primerima aluvijalnih vodotokova<br />izabrane su dve deonice reke Dunav. Prva lokacija se nalazi u pograniˇcnoj zoni<br />između Mađarske i Srbije gde su testirani aspekti modela koji se odnose na<br />proracun tečenja i pona&scaron;anje nanosa. Druga deoncia se nalazi kod Beograda<br />gde je, pored proračuna strujanja i nanosa, vr&scaron;ena analiza modela transporta zagađujuće materije obuhvatajući sve relevantne mehanizme i aspekte izučavanih<br />procesa. Upoređivanjem terenskih merenja i rezultata proračuna je konstatovano<br />da razvijeni model može simulirati interakciju vode, nanosa i zagađivača u prirodnim vodotocima sa zadovoljavajucom tačno&scaron;ću i pouzdano&scaron;ću.<br />&nbsp;</p> / <p>This work presents the development of a two-dimensional model for flow, sediment<br />and pollutant interaction in natural watercourses. The model incorporates water<br />flow computation, both aspects of sediment transport (suspended and bed-load),<br />the mechanisms of exchange between suspended and bed sediment, bed evolution<br />due to erosion and deposition, the mechanisms of exchange between active layer<br />and active stratum sediment, as well as the processes of nonconservative pollutant<br />transport including its interaction with sediment particles by adsorption/desorption.<br />Deriving the governing equations for pollutant transport included the dissolved and<br />adsorbed pollutant. The exchange between the dissolved and adsorbed pollutant<br />was described using a first order kinetic process, while the modeling of the exchange<br />coefficients remained closely related to the sediment surface available for adsorption.<br />On the other hand, the exchange between the pollutant adsorbed on suspended sediment and the pollutant adsorbed on active layer sediment was directly related<br />to the sediment processes of entrainment and deposition. Numerical tests included<br />the evaluation of the developed algorithm for advection terms. The second group<br />of numerical tests targeted the pollutant transport model, with the emphasis on<br />the mechanisms of exchange and interaction. For field test cases two reaches of the<br />Danube River were used. The first reach was located in the border area between<br />Hungary and Serbia. Field data collected there was used to analyze the developed<br />model&rsquo;s ability to simulate flow and sediment transport. Data collected on the second reach near Belgrade was used to perform flow, sediment and pollutant transport<br />simulations, taking into account all the relevant mechanisms of the studied processes.<br />Comparing the computed and measured values, it was concluded that the developed<br />model is able to simulate the interaction of flow, sediment and pollutant in natural<br />watercourses with acceptable precision and reliability.</p>

O presente trabalho apresenta os resultados obtidos na avaliação dos problemas ambientais relacionados a lixiviação de poluentes do lixão próximo ao Ribeirão dos Moinhos na cidade de Poços de Caldas (MG). O estudo considera as características geológicas - geotécnicas e climáticas da área e os vários tipos de técnicas de \"cleanup\". O software Visual Modflow foi usado para desenvolver simulações em termos de fluxo de água subsuperficial e de transporte de poluentes. / This work presents the results obtained from assessment of the environment problems related to the pollutant lixiviation from the urban wastes disposed near the Moinho River in Poços de Caldas (MG) city. The study considered the geological - geotechnical and climatic characteristics of the area and the main kinds of cleanup techniques. The software Visual Modflow were used to developed the simulation in terms of groundwater flow and pollutant transport.