La maîtrise des flux de polluants générés par temps de pluie en milieu urbain constitue un enjeu important pour limiter la dégradation des milieux aquatiques superficiels. Face à l’insuffisance des systèmes d’assainissement traditionnels, la gestion à la source des eaux pluviales, dans des dispositifs de stockage à ciel ouvert intégrés au milieu urbain, s’est progressivement imposée comme une solution permettant de réduire de façon significative les flux de contaminants dirigés vers les réseaux ou les milieux récepteurs, en favorisant notamment l’infiltration ou l’évapotranspiration des volumes ruisselés. Bien qu’offrant des perspectives pour la maîtrise des flux de polluants, l’efficacité des solutions mises en œuvre n’est à ce jour pas suffisamment maîtrisée. Ce travail de thèse s’intéresse donc à l’incidence du fonctionnement hydrologique des « techniques alternatives » de gestion à la source du ruissellement et vise en particulier à orienter leur conception pour garantir une meilleure maîtrise de la contamination des eaux pluviales urbaines.Les pratiques actuelles de gestion des eaux pluviales urbaines sont dans un premier temps analysées de manière à identifier les stratégies pouvant être préconisées pour la maîtrise à la source des flux de polluants. Ce travail permet alors de mettre en évidence l’hétérogénéité quant à la traduction de l’objectif de maîtrise des flux de polluants dans les préconisations à destination des aménageurs, qui ne garantissent pas nécessairement la mise en œuvre de solutions permettant de limiter efficacement les rejets de contaminants vers les milieux récepteurs.Une chaîne de modélisation « surface urbaine + ouvrage », destinée à simuler le fonctionnement des dispositifs de gestion à la source des eaux pluviales pour des périodes longues de précipitations, et en considérant des dynamiques variées de production des flux d’eau et de contaminants au niveau des bassins versants d’apport, est par la suite développée afin de préciser l’incidence de différents scénarios de gestion du ruissellement ou de dimensionnement des techniques alternatives sur les flux rejetés vers l’aval. Certaines composantes de cette chaîne de modélisation font l’objet d’un approfondissement, avec l’introduction (1) d’un schéma permettant de simuler l’évolution de l’état hydrique du sol pour mieux rendre compte de la variabilité temporelle des flux d’infiltration et (2) d’un modèle générique destiné à simuler des dynamiques contrastées d’émission des contaminants (matières en suspension lessivées au niveau des chaussées urbaines et zinc dissous au niveau d’éléments de toiture métalliques). Une analyse de sensibilité cette chaîne de modélisation est par la suite réalisée afin de préciser l’incidence de sa paramétrisation et d’évaluer l’importance de certaines hypothèses simplificatrices pour l’estimation de l’efficacité des techniques alternatives.L’intérêt de la chaîne de modélisation développée dans le cadre de ce travail est finalement illustré par la construction d’abaques permettant de relier l’efficacité des techniques alternatives à quelques paramètres de dimensionnement et d’évaluer la pertinence de différents scénarios de gestion du ruissellement. Les résultats, correspondant ici aux conditions météorologiques de la région Ile-de-France, indiquent que l’abattement d’une fraction modeste du ruissellement, grâce à un simple volume mort, pourrait donner lieu à une réduction importante des rejets de contaminants pour les sols de conductivité hydraulique supérieure à 10-6 m.s-1. Dans le cas sols présentant des capacités d’infiltration plus limitées, l’analyse met en revanche en évidence un risque de dysfonctionnement des dispositifs de gestion. Le recours à des solutions « plus diffuses », peu profondes et présentant des surfaces d’infiltration ou d’évapotranspiration importantes, apparaît alors préférable pour garantir des niveaux d’efficacité satisfaisants tout en évitant une sollicitation excessive de l’ouvrage. / Urban runoff discharge is today identified a major source of surface water impairment. In recent years, on-site stormwater control, in small and relatively simple vegetated systems, providing volume reduction through infiltration or evapotranspiration, has become increasingly popular due to the inability of conventional drainage systems to limit the amount of stormwater and pollutant directed to the environment. While such practices clearly offer opportunities to mitigate the adverse effects of urban runoff, their performance remains insufficient and is yet not completely understood. The main purpose of this Ph.D. thesis is therefore to investigate the relation between the hydrological behaviour of these source-control systems and pollutant removal efficiencies so as to provide design tools or guidelines that support practitioners in the implementation of efficient stormwater management practices.Current stormwater management practices are first examined on the basis of a literature review of various guidelines or regulatory documents so as to identify the strategies that may be promoted for on-site pollution control, in France or abroad. This analysis indicates that recommendations can be quite variable depending on the country or the community and do not systematically reflect on-site pollution control objectives, which may result in the implementation of inappropriate stormwater management systems.A modelling system based on the representation of a pervious facility collecting runoff and pollutant loads generated over a small urban catchment, allowing the simulation of different scenarios in terms of urban surfaces characteristics and source-control system design, for long rainfall periods, is later developed to investigate the relation between the hydrological behaviour and the pollutant removal efficiencies of on-site stormwater management practices. An improved description of the hydrological processes in the source control system is adopted with the introduction of an infiltration-redistribution scheme accounting for the evolution of soil moisture so as to better replicate the temporal variability of infiltration fluxes. The opportunity of implementing relatively simple conceptual runoff quality models to simulate distinctive pollutant emission dynamics is also investigated: a generic model formulation is adopted and calibrated to replicate suspended solids concentrations in urban street runoff or zinc concentrations from a metal roof. A sensitivity analysis of the modelling system is later conducted so as to evaluate the influence of the different input factors and better understand the effect of some modelling hypotheses for the assessment of the performance of stormwater source control practices.The practical value of the modelling system is finally illustrated with the production of sizing diagrams displaying pollution control efficiency estimates as a function a limited number of design parameters, from which the relevance of a large variety of runoff control scenarios may be evaluated. The results presented in this study, corresponding to the rainfall conditions encountered in Paris region, suggest that the infiltration or evapotranspiration of a relatively small fraction of runoff in a simple dead storage volume could result in a significant reduction of pollutant discharges for soils exhibiting saturated hydraulic conductivity values greater than 10-6 m.s-1. In the case of lower saturated hydraulic conductivity values, this study however evidences possible failures of source control system due to a limited drainage capacity (extended ponding duration and saturation of the soil profile over significant depths). Results therefore suggest that the implementation diffuse stormwater management practices, with large infiltration/evapotranspiration areas and limited storage depths, should generally be preferred to achieve pollution control and ensure correct hydrological functioning of the source control systems.

É analisado o desempenho de um motor de ignição por compressão turboalimentado por uma mistura temária de combustíveis (diesel, biodiesel e etanol) através do comportamento do motor operando com um combustível principal, o qual poderá ser o diesel ou biodiesel ou misturas destes dois, com e sem sua substituição parcial por etanol no coletor de admissão. A análise do desempenho é feita através das curvas de torque, potência, rendimento térmico e consumo específico de combustível. A combustão do motor é estudada através de um programa simulador que utiliza um modelo zero-dimensional, que avalia a taxa de liberação de calor durante a combustão e tem como dado de entrada a curva de evolução da pressão dentro do cilindro. Faz-se a identificação e quantificação do fenômeno da detonação utilizando análise espectral, através do sinal de pressão da câmara de combustão, para o motor operando com diversas misturas combustíveis. São analisadas também as emissões gasosas do motor com as misturas, e a viabilidade técnica do uso de biodiesel em motores de ignição por compressão, além de um estudo geral sobre o uso do éster de óleo vegetal. / The performance of a three-fuel system (diesel, biodiesel and ethanol) turbocharged compression-ignition engine is analyzed, through the engine behavior supplied by mixtures of diesel or biodiesel or mixtures of these fuels with ethanol in the intake manifold. The performance analysis is made by torque, power, specific fuel consumption and thermal efficiency curves. The engine combustion is studied by a simulator program that uses a zero-dimensional model, that evaluate the heat release rate during the combustion and it has as input data the pressure evolution curves inside the cylinder. The knocking phenomenon is studied by spectral analysis. The pollutant gases emissions and the technical viability of the utilization of biodiesel also are analyzed, beyond a general study about of vegetal oil ester.

A criação de camarões marinhos em cativeiro tem sido acusada de causar sérios impactos ambientais, sobretudo em função do lançamento de grandes quantidades de nutrientes e metais pesados nas águas estuarinas. Diversos estudos realizados nos principais estados produtores de camarão no Brasil, através do uso de fatores de emissão, estimaram as cargas destes poluentes para seus principais estuários. Neles ficou caracterizada a importância desta atividade como fonte de nutrientes, uma vez que a carcinicultura dominou as emissões de nitrogênio para os estuários dos rios Açu (RN) e Jaguaribe (CE). Ocorre que esses estudos consideraram a forma de cultivo de camarão, predominante há alguns anos, a qual estava baseada em uma produção intensiva. Desta forma, devem ser consideradas as alterações nos processos produtivos dessa atividade, e precisam ser determinados novos fatores de emissão. O estuário do rio Potengi (RN), objeto de estudo, apresenta características que o tornam bastante susceptível a elevadas depreciações da qualidade de suas águas, pelo fato de nessa bacia hidrográfica estar implantada a capital do estado, cidade com maiores contingente populacional e grau de urbanização do RN. O presente trabalho trata da determinação de novos fatores de emissão relativos a nutrientes e a metais pesados para a carcinicultura, com base na realidade atual desta atividade no estuário do rio Potengi e avalia, também a importância da carcinicultura como fonte de nutrientes e metais pesados para o referido estuário. Estes novos fatores de emissão foram determinados e serviram como base para estimativa da carga anual da carcinicultura; também foram determinadas as cargas de outras fontes naturais e antrópicas presentes no ecossistema de estudo o que permitiu verificar que a carcinicultura, apesar de não ser a atividade predominante, constitui fonte ) importante de nitrogênio (5,28%), cobre (10,54%) e zinco (14,04%). / The creation of marine shrimp in captivity has been blamed for causing serious environmental impacts, particularly through the release of large amounts of nutrients and heavy metals in estuarine waters. Several studies in the major shrimp-producing states in Brazil, through the use of emission factors, estimated the loads of these pollutants to their main estuaries. In them was a characteristic aspect of this activity as a source of nutrients, since the carciniculture dominated the emission of nitrogen to the estuaries of the Acu (RN) and Jaguaribe (CE). It turns out that these studies considered the form of shrimp farming, prevalent a few years ago, which was based on an intensive production. Thus, should be considered the changes in production processes of this activity, and need to be certain new emission factors. The estuary Potengi (RN), the object of study, has characteristics which make it very susceptible to high depreciation of the quality of the water, because this basin has been introduced to the state capital city with the highest overall population and degree of urbanization of the RN. This paper deals with the new emission factors for nutrients and heavy metals in the carciniculture, based on the current reality of this activity in the estuary Potengi and evaluates also the importance of carciniculture as a source of nutrients and heavy metals in that estuary. These new emission factors were determined and served as a basis to estimate the annual load of carciniculture, were also determined loads of other natural and anthropogenic sources in the ecosystem of the study that showed that the carciniculture, though not the predominant activity, constitutes an important source of nitrogen (5.28%), copper (10.54%) and zinc (14.04%).

O presente trabalho trata do desenvolvimento um novo material, diatomita modificada por ferro, como ativador dos oxidantes persulfato de sódio e peróxido de hidrogênio para degradar poluentes prioritários (fenantreno e antraceno), diesel e o poluente emergente ácido perfluoroctanóico (PFOA). Os objetivos deste estudo foram comparar esse novo método com métodos convencionais de ativação para esses oxidantes; e estudar, estatisticamente, a relação ótima entre a quantidade deste material e a concentração de oxidante para a degradação dos contaminantes. A diatomita bruta e as diatomitas modificadas (CAT-5 e CAT-20) foram caracterizadas por diferentes técnicas. Os principais resultados da caracterização mostraram que os materiais são amorfos e que a concentração de ferro foi 4%, 17% e 25% para diatomita bruta, CAT-5 e CAT-20, respectivamente. Os resultados mostraram que os materiais modificados apresentaram significativa atividade catalítica para ativar os oxidantes e degradar os poluentes, sendo a CAT-5 a mais reativa. Resultados satisfatórios foram obtidos utilizando 45 g L-1 de persulfato de sódio com 2,5 g de diatomita modificada (CAT-5), com degradação de 87% e 96% de fenantreno e antraceno, respectivamente, em 168 horas de tratamento. Para o tratamento de solo arenoso contaminado com diesel, os melhores resultados foram obtidos utilizando 41 g L-1 de persulfato de sódio e 1,56 g de CAT-5, obtendo decaimento de 91% de carbono total em 146 horas. A eficiência da decomposição de PFOA mostra que a reatividade dos sistemas seguiu a ordem: peróxido de hidrogênio em altas concentrações > peróxido de hidrogênio em paralelo com persulfato > persulfato alcalino, ambos ativados com CAT-5, atingindo 86%, 69% e 48%, respectivamente, após 6 horas de reação. / The present work deals with the development of a new materials, modified diatomite by iron, as an activator of the oxidants sodium persulfate and hydrogen peroxide to degrade priority pollutants (phenantherene and anthracene), diesel and emerging pollutant perfluorooctanoic acid (PFOA). The aims of this study were to compare this new method with traditional activation method for these oxidants; and to study, statistically, the optimal ratio between the quantity of the material and the concentration of oxidant to the degradation of contaminants. The raw and modified materials were characterized by different techniques. The main characterization results showed that materials are amorphous, and that the iron concentrations were 4,78%, 17,65% and 25% for the raw diatomite, CAT-5 and CAT-20, respectively. The results showed that the modified material showed significant catalytic activity to activate the oxidants and to degrade pollutants, with CAT-5 being the most reactive. Satisfactory results were obtained using 2,5 g of modified diatomite (CAT-%) with sodium persulfate at 45 g L-1, with degradation of 87% and 96% of phenanthrene and anthracene, respectively, in 168 hours of treatment. For the treatment of sandy soil contaminated with diesel, the best result was obtained using 41 g L-1 of sodium persulfate sodium and 1,56 g of CAT-5, resulting in a decrease of 91% of total carbon present in diesel. The PFOA decomposition efficiency for the systems shows that hydrogen peroxide at high concentrations > hydrogen peroxide-activated persulfate > alkaline-activated persulfate, both with CAT-5, achieving 83%, 69% and 48% , respectively, after 6 hours of reaction.

É analisado o desempenho de um motor de ignição por compressão turboalimentado por uma mistura temária de combustíveis (diesel, biodiesel e etanol) através do comportamento do motor operando com um combustível principal, o qual poderá ser o diesel ou biodiesel ou misturas destes dois, com e sem sua substituição parcial por etanol no coletor de admissão. A análise do desempenho é feita através das curvas de torque, potência, rendimento térmico e consumo específico de combustível. A combustão do motor é estudada através de um programa simulador que utiliza um modelo zero-dimensional, que avalia a taxa de liberação de calor durante a combustão e tem como dado de entrada a curva de evolução da pressão dentro do cilindro. Faz-se a identificação e quantificação do fenômeno da detonação utilizando análise espectral, através do sinal de pressão da câmara de combustão, para o motor operando com diversas misturas combustíveis. São analisadas também as emissões gasosas do motor com as misturas, e a viabilidade técnica do uso de biodiesel em motores de ignição por compressão, além de um estudo geral sobre o uso do éster de óleo vegetal. / The performance of a three-fuel system (diesel, biodiesel and ethanol) turbocharged compression-ignition engine is analyzed, through the engine behavior supplied by mixtures of diesel or biodiesel or mixtures of these fuels with ethanol in the intake manifold. The performance analysis is made by torque, power, specific fuel consumption and thermal efficiency curves. The engine combustion is studied by a simulator program that uses a zero-dimensional model, that evaluate the heat release rate during the combustion and it has as input data the pressure evolution curves inside the cylinder. The knocking phenomenon is studied by spectral analysis. The pollutant gases emissions and the technical viability of the utilization of biodiesel also are analyzed, beyond a general study about of vegetal oil ester.

Devido à necessidade de se conhecer os impactos que as diversas atividades antropogênicas exercem sobre os ecossistemas torna-se relevante o estudo dos organismos aquáticos perante os resíduos tóxicos resultantes, com o objetivo de facilitar a identificação de áreas poluiídas ou contaminadas e estudos de meios atingidos por estes agentes poluentes. Estudo da microalga em contato com o fenol em concentrações conhecidas, compreende a determinação dos efeitos tóxicos e geração de metabólitos, caracterizando uma possível utilização deste microorganismo como bioindicador para contaminações do poluente. Determinou-se as concentrações de fenol capazes de em 24 horas inibirem o crescimento das células de L. polyedrum em 20 e 50% (IC 20 e IC 50) respectivamente 40 µmol.L-1 e 120 µmol.L-1. Identificou-se a necessidade de padronização das variáveis na execução dos ensaios dose-resposta com algas, permitindo construir protocolos que auxiliariam a obtenção de legislações que assegurem os limites de compostos tóxicos aos organismos costeiros. Calculou-se que a microalga L. polyedrum possui uma taxa de biodegradação do fenol por célula na média de aproximadamente (0,02 µmol.h-1.cel-1), capaz de biotransformar 120 µmol.L-1 de fenol em um período de 16 horas. Vias de biotransformação do fenol na microalga L.polyedrum se dão pela conjugação com a glutationa, catalisada por glutationa S-transferase e pela via metabólica de fenol hidroxilase e catecol 2,3-dihidroxigenase. Identificou-se a geração do ácido 2-hidroximucônico semialdeído, 1,2-dihidroxibenzeno (Catecol) e ácido 2-oxo 4-pentenóico como metabólitos resultantes da exposição de L. polyedrum ao fenol. O composto orgânico fenol é capaz de induzir um estado de aumento na atividade antioxidante da microalga L. polyedrum, sendo as enzimas superóxido dismutase e catalase os melhores biomarcadores, por terem sua expressão até três vezes maior no grupo exposto. Determinou-se que a razão GSH/GSSG no grupo tratado com fenol é menor, devido ao aumento de 20 ng.mL-1 de GSSG, expressando o efeito oxidativo no sistema glutationa, que em condições normais possui os níveis de GSSG muito abaixo dos de GSH. A avaliação fotossintética sugeriu que o fenol interferiu relativamente na fotossíntese da microalga em um curto intervalo de tempo, demonstrando a promissora sensibilidade a este poluente presente no ambiente marinho. / Due necessity of knowing and understand the impacts of diverse anthropogenic activities exerted above ecosystems became relevant the study of aquatic organisms exposed to toxic waste, this can facilitate the identification of polluted or contaminated areas. Study of microalgae in contact with phenol at known concentrations, comprehended a determination of the toxic effects and generation metabolites of characterizing the possible use of the organism as a bioindicator to contamination of the pollutant. In this work it was determined in 24 hours those inhibitor phenol concentrations of cell growth of L.polyedrum on 20% and 50% (IC 20 and IC 50) respectively 40 µmol.L-1 and 120 µmol.L-1. Acknowledged need for standardization of variables in the implementation of dose-response tests with algae, allowing you to build protocols that would help to obtain laws that ensure the limits of toxic compounds to coastal organisms. It was assumed that the L. polyedrum microalgae has a biodegradation rate of phenol per cell on average of about (0,02 µmol.h-1.cel-1), capable of biotransformation 120 µmol.L-1 of phenol in a period of 16 hours. Biotransformation pathways of phenol in the microalgae L. polyedrum occur by conjugation with glutathione, catalyzed by glutathione S-transferase and the metabolic pathway of phenol hydroxylase and catechol 2,3-dihydroxygenase. We identified 2- hydroxy muconic semialdehyde acid, 1,2-dihydroxybenzene (catechol) and 2-oxo-4-pentenoic acid as metabolites resulting from exposure to phenol. The phenol is able to induce a high active antioxidant enzymes on L. polyhedron, and the enzymes superoxide dismutase and catalase the best biomarkers since were induced three times more in the exposed group. It was determined that the GSH / GSSG ratio in the group treated with phenol, GSSG has an increase of 20 ng.mL-1. Evaluation suggested that the phenol interfered on photosynthesis of microalgae in a short time, showing promising sensitivity to this pollutant in the marine environment.

A exposição de camundongos neonatos ao poluente 1,2-naftoquinona (1,2-NQ) induziu maior suscetibilidade dos machos jovens (mas não fêmeas) à asma. O objetivo deste estudo foi investigar o impacto da 1,2-NQ no pulmão de camundongos jovens machos e fêmeas e averiguar as associações entre os receptores de potencial transitório TRPA1 e a 1,2-NQ. Camundongos machos e fêmeas C57Bl/6 (2-5 g) foram expostos a 1,2-NQ (100 nM). Maior atividade da catalase e expressão (RNAm) do Nrf2 foi observado no pulmão das fêmeas 24 h após a exposição da 1,2-NQ. O estímulo alérgico na puberdade aumentou a atividade da glutationa peroxidase, redutase e S-transferase nas fêmeas que, diferentemente dos machos, não exibiram exacerbação da asma, mas mostraram maior nitração e carbonilação proteica, expressão da eNOS e TRPA1. O antagonismo dos TRPA1 reduziu a eosinofilia pulmonar nos machos e inibiu a [Ca2+]i em cultura de neurônios frente a 1,2-NQ. A ausência susceptibilidade em fêmeas se deve a maior defesa antioxidante e a maturidade pulmonar destas. / The mice exposure to 1,2-naphthoquinone (1,2-NQ), during postnatal period induced increased susceptibility of males (but not females) to asthma. The aim of this study was to investigate the intensity of lung damage to impact of 1,2-NQ on young mice of both sexes, and to investigate the associations between TRPA1 and 1,2-NQ. Male and female C57Bl/6 mice (2-5g) were exposed to 1,2-NQ (100 nM). After 24 h postnatal exposure to 1,2-NQ, only female lungs showed increased catalase activity and Nrf2 mRNA expression. The allergic stimuli at puberty led to increased glutathione peroxidase, reductase and S-transferase activities only in female lung, which, unlike male, did not exhibit exacerbation of asma, but showed increased pulmonary nitration and protein carbonylation, and increased mRNA expression of eNOS and TRPA1. The TRPA1 antagonist reduced eosinophilia in male lung and inhibited the increased [Ca2+]i in dorsal root ganglion neurons culture to 1,2-NQ. The lack of susceptibility in female might be linked to increased antioxidant defenses and the pulmonary maturity.

For bioactive chemical classes, it is often assumed that environmental transformation eliminates associated ecosystem risks. However, for endocrine-active steroid hormones, modest changes in structure can have a significant influence on biological activity and thus, subtle environmental transformations can yield products with conserved, enhanced, or activity across different biological endpoints. The aim of this work was to explore the environmental fate of high potency, endocrine-active steroid hormones during natural or engineered water processes in order to test the hypothesis that steroid transformation products generated during these processes are likely to contribute to residual bioactivity often reported in water resources. Specifically, laboratory experiments were used to simulate chemical disinfection (e.g., chlorination) or natural processes (e.g., photolysis) to: (i) determine the rate and extent of steroid transformation, (ii) isolate and identify products that are formed, and (iii) evaluate products or product mixtures for biological activity. These experimental results can be used to help guide occurrence studies for any products of concern in the environment and also guide computational predictions or rationalizations of chemical reactivity. Ultimately, the goal is to expand upon our awareness and understanding of how these potent endocrine ligands behave in the environment and how they potentially affect ecosystem health. Chapter 2 discusses the reaction of glucocorticoids (GC)s with aqueous chlorine (effectively, HOCl) to simulate their fate during engineered drinking water and wastewater chemical disinfection. Numerous transformation pathways were unveiled, including interconversion of GCs (e.g., endogenous cortisol to synthetic prednisolone), production of known androgens in the adrenosterone class, and chlorination of GCs (e.g., formation of 9-chloro-prednisone). We also showed that other advanced processes (e.g., oxidation via ozonation) result in more complete degradation of such pollutants, and may be better alternatives to chemical disinfection at eliminating bioactive steroidal product formation. In Chapter 3, results of the direct photolysis of dienogest (DNG), a widely prescribed oral contraceptive agent, are presented to simulate its fate in natural sunlit surface waters and engineered photochemical treatment systems (e.g., UV disinfection systems). The major products (~ 80% of the converted mass in neutral aqueous solutions) were identified to be photohydrates resulting from photochemical-induced incorporation of water into parent DNG. These products were found to be prone to dehydration in the dark, and thus, a source of substantial DNG regeneration (~ 65% after 72 h in neutral solutions). Other minor, non-revertible products were also identified, including two known estrogens. Although minor in initial yield, these estrogens are likely to accumulate over time through repeated cycling between DNG and its photohydrates, and thus, dominate DNG long-term fate. It was also found that DNG undergoes an unusual photochemical rearrangement to produce a minor product with a novel tetracyclic ring system--the subject of Chapter 4. Further, the generality of this unique photorearrangement process was explored through extension to the photolysis of two other dienone pharmaceutical steroids (e.g., the androgens methyldienolone and dienedione). Surprisingly, despite the significant change in core steroidal structure, the rearrangement products retain some progesterone receptor (PR) and androgen receptor (AR) bioactivity (i.e., low-µM to sub-nm EC50 values). Again, these represent other non-revertible, minor products that are likely to accumulate over time, with likely adverse ecological consequences. Chapter 5 covers results arising from the direct photolysis of trenbolone acetate (TBA) metabolites in the presence of model nucleophiles (e.g., sodium azide, sodium thiosulfate, ammonium hydroxide, hydroxylamine, and humic acid), some of which would be expected to be present, along with TBA metabolites, in agriculturally-impacted water resources. Previous studies by our group revealed that TBA metabolites undergo photohydration-thermal dehydration cycling, like that described above for DNG photolysis. The objective of this study was to determine if other nucleophiles would outcompete water for photochemical incorporation across the TBA metabolite extended conjugation system. It was found that TBA metabolite photolysis results in photochemical (and at times thermal) addition of the nucleophile to the TBA metabolites. It was also found that the addition products undergo thermal elimination in the dark and contribute to TBA metabolite regeneration, and therefore, are expected to increase TBA metabolite persistence in water resources. Finally, Chapter 6 discusses the reactions of various trienone and dienone steroids with aqueous chlorine to simulate their fate during engineered drinking water and wastewater chemical disinfection. Single-step transformation pathways were unveiled for each steroid class, including 4-chlorination (trienones) and 9,10-epoxidation (dienones). Chlorination at position C-4 is known to enhance anabolic potency of androgenic steroids and the 9,10-epoxy products were found to undergo acid- or base-catalyzed ring-opening and aromatization to yield known estrogenic products. In addition, Chapter 7 provides conclusions and future directions, while Chapter 8 details the experimental methods and procedures used throughout this thesis. Collectively, the results presented herein confirm our overall hypothesis that steroid transformation products would be expected to contribute to residual biological activity often detected in water resources. Furthermore, the results indicate that the transformation of high potency pharmaceuticals does not automatically equate with reduction or elimination of hazards to exposed organisms, especially in cases where such compounds have potential to form products exhibiting diverse biological endpoints. More holistic approaches to risk assessment of such high potency environmental contaminants are needed in order to accurately assess the fate and effects of such emerging pollutant classes and their bioactive transformation products.

Appropriately constructed pollutant export models can help set management priorities for catchments, identify critical pollutant source areas, and are important tools for developing and evaluating economically viable ways of minimising surface water pollution.¶ This thesis presents a comparison, an evaluation and an integration of models for predicting the export of environmental pollutants, in particular sediment, through river systems. A review of the capabilities and limitations of current water quality modelling approaches is made. Several water quality and quantity modelling approaches are applied and evaluated in the catchment of the upper Murrumbidgee River.¶ The IHACRES rainfall-runoff model and a simple hydrologic routing model are applied with the aim of developing a capacity to predict streamflow at various catchment scales and to enable integration with other pollutant load estimation techniques. Methods for calculating pollutant loads from observed pollutant concentration and modelled streamflow data are also investigated. Sediment export is estimated using these methods over a 10-year period for two case study subcatchments. Approaches for water quality sampling are discussed and a novel monitoring program using rising stage siphon samplers is presented. Results from a refinement of the Sediment River Network model in the upper Murrumbidgee catchment (SedNet-UM) are presented. The model provides a capacity to quantify sediment source, transport and to simulate the effects of management change in the catchment. The investigation of the model includes rigorous examination of the behaviour of the model through sensitivity assessment and comparison with other sediment modelling studies. The major conclusion reached through sensitivity assessment was that the outputs of the model are most sensitive to perturbation of the hydrologic parameters of the model.¶ The SedNet-UM application demonstrates that it is possible to construct stream pollutant models that assist in prioritising management across catchment scales. It can be concluded that SedNet and similar variants have much potential to address common resource management issues requiring the identification of the source, propagation and fate of environmental pollutants. In addition, incorporating the strengths of a conceptual rainfall-runoff model and the semi-distributed SedNet model has been identified as very useful for the future prediction of environmental pollutant export.

<p>Karakalpakstan, Uzbekistan, has faced water scarcity and low water during several years as a consequence of Uzbekistan’s extensive irrigation of cotton fields. The environmental status of the Mejdurechye Reservoir, which is the largest in the lower Amudarya Delta, is therefore of great local importance. This thesis quantifies pollutant mass flows through the reservoir, concidering for instance salt, DDT and Lindane (HCH). Surface water flow paths through Mejdurechye Reservoir are also conceptualized in order to provide suggestions for future a possible monitoring program.</p><p>Results show that chloride concentrations have decreased during July 2007-2008 with at least 10% in spite of a large specific evaporation and a reservoir volume reduction of at least 60%. The most important implication of this is that pollutants in the reservoir cannot have been subject of evapoconcentration during this period. DDT and Lindane have on the other hand increased with up to 50000% in concentration and 20000% mass compared to measurements dating back to 2002. A rough age estimation of DDT shows that the DDT has been mobilized recently. The results of this thesis may prove valuable when forming environmental policy plans and setting up future monitoring programs.</p>