Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2018-06-12T12:51:45Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_dominique_dos_santos_delias.pdf: 20779 bytes, checksum: d36acefcc1527cd70d1cb395df0062d3 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-06-12T18:44:08Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_dominique_dos_santos_delias.pdf: 20779 bytes, checksum: d36acefcc1527cd70d1cb395df0062d3 (MD5) / Made available in DSpace on 2018-06-12T18:44:08Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) resumo_tese_dominique_dos_santos_delias.pdf: 20779 bytes, checksum: d36acefcc1527cd70d1cb395df0062d3 (MD5) Previous issue date: 2017-06-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / O ferro é um micronutriente essencial para a manutenção da vida das plantas, estando envolvido nos processos de crescimento e desenvolvimento dos vegetais. O objetivo do trabalho foi avaliar o efeito de níveis tóxicos de Fe sobre as características fotossintéticas, bioquímicas, sintomas visuais de toxicidade e estado nutricional de plantas de soja em condições de normóxia e hipóxia. As plantas foram cultivadas em sistema de hidroponia e os experimentos conduzidos com os sistemas radiculares sob duas disponibilidades de O2: normóxia (com aeração) e hipóxia (borbulhamento de gás N2), utilizando solução de Hoagland contendo ferro na forma de EDTA-férrico em diferentes concentrações. O trabalho foi realizado em duas etapas: na primeira etapa buscou-se testar e selecionar as doses de ferro para análises de respostas das plantas em condições de normóxia (0,9; 13,5 e 18 mM), e posteriormente em condições de hipóxia (0,9; 4,5; 9,0; 13,5 e 18 mM) por um período de 144 horas. Foram avaliadas as trocas gasosas (A, Ci, gs, E) e índice de clorofila às 72h e 144h de exposição e o acúmulo de massa seca e análise da composição mineral em folhas e raízes, ao final dos experimentos (144h de exposição). Na segunda etapa, as plantas foram expostas a doses de ferro (0,9 - controle; 9,0; 18; 27 e 36 mM) combinados à normóxia e hipóxia, por um período de 72 horas. Foram feitas avaliações dos parâmetros de trocas gasosas (A, Ci, gs, E, A/Ci) após 24h de exposição. As demais avaliações ocorreram após 72h, sendo mensuradas as atividades de enzimas antioxidantes, níveis de peroxidação lipídica, teores de pigmentos cloroplastídicos, prolina, avaliação da composição de nutrientes minerais e sintomas de toxidez e acúmulo de massa seca. O excesso de Fe provocou redução de biomassa em todos os experimentos, ocorrendo redução mais drástica em plantas sob hipóxia. Na primeira etapa, sob condição de normóxia, houve diminuição na Ci e do índice de clorofila, com aumento da transpiração nas plantas submetidas à dose mais alta de ferro nos dois tempos avaliados. Na segunda etapa da pesquisa, as atividades da SOD, CAT e APX foram maiores conforme o aumento das doses de ferro. O aumento de Fe nos tecidos resultou em acúmulo crescente de prolina nas folhas, com maior intensidade no tratamento hipóxia. O excesso de ferro afetou a absorção e translocação de nutrientes. Assim, os resultados sugerem que plantas de soja quando expostas a altas doses de ferro, apresentam sintomas de toxidez que comprometem o funcionamento do aparato fotossintético e a distribuição de outros nutrientes na planta, porém observou-se atuação do sistema antioxidante enzimático e não-enzimático na tentativa de atenuar o estresse causado por ferro. / Iron is an essential micronutrient for the maintenance of plant’s life, it is involved in growth and developmental processes of plants.The aim of this study was to evaluate the effect of toxic levels of Fe on biochemical and photosynthetic characteristics, visual symptoms of toxicity and nutritional state of soybean plants at normoxia and hypoxia conditions. Plants were grown in a hydroponic system and the experiments were carried out with root systems of plants under normoxia (air flushing) e hypoxia (N2 flushing), in Hoagland solution containing different concentrations of iron (Ferric- EDTA). The research was carried out in two steps: In the first step, tests were done in order to select and test iron concentrations to analyse responses of plants under normoxic conditions (0,9; 13,5 e 18 mM), and posteriorly under hypoxia conditions (0,9; 4,5; 9,0; 13,5 e 18 mM) for a 144 h period. Gas exchange parameters (A, Ci, gs, E) and chlorophyll index were evaluated at 72 h and 144h of exposition to treatments and dry mass accumulation and mineral composition analysis in leaves and roots, at 144h of exposition. In the second step, plants were exposed to Fe concentrations (0,9; 9,0; 18; 27 e 36 mM) under normoxia and hypoxia, for a period of 72 hours. Parameters of gas exchange (A, Ci, gs, E e A/Ci) were evaluated after 24h of exposition to treatments. At 72h, biochemical analysis were evaluated: antioxidant enzymes activities (SOD, CAT e APX), levels of lipid peroxidation, chloroplastic pigments, proline, composition of mineral nutrients, toxicity symptons and dry mass accumulation. Excess of iron caused a biomass reduction of soybean plants in all experiments, and the effect was more severe in plants submitted to hypoxia. In the first step, under normoxia, Ci and chlorophyll index decreased, and transpiration increased in plants submitted to highest iron concentration in both periods. In the second step of this research, SOD, CAT and APX activities were higher according to increase of iron concentrations in both conditions. Fe increase in tissues, resulted in accumulation of proline in leaves, with higher intensity in hypoxia treatment. Excess of iron affected uptake and translocation of nutrients. Results suggest that soybean plants when exposed to high concentrations of iron, show symptoms of toxicity that weaks the functionality of photosynthetic apparatus and distribution of other nutrients in the whole plant, however in a opposite way, enzimatic and non-enzimatic antioxidant system increased in order to attenuate the stress caused by iron.

Au cours de notre travail de thèse, nous avons isolé la seconde espèce du genre Gemmata, Gemmata massiliana à partir de l'eau d'un réseau hospitalier. Nous avons étudié sa distribution dans deux réseaux hospitaliers à Marseille après avoir mis au point une PCR temps réel spécifique. Les échantillons d'eau filtrée recueillis dans l'unité de soins intensifs et des échantillons d'eau non-filtrée recueillis dans des fauteuils dentaires, des réservoirs et des points d'utilisation ont été testés. Au total, 2,2% des échantillons d'eau filtrée ont été positifs contre 11,3% des points d'eau non-filtrée, dont 14,1% des fauteuils dentaires, 5,9% des points d'utilisation et 8% des échantillons de réservoirs. Les patients hospitalisés peuvent être exposés à G. massiliana par l'intermédiaire de l'eau de l'hôpital. Le rôle des Gemmata comme pathogènes opportunistes méritait donc d'être exploré. Nous avons détecter de l'ADN de Planctomycetes dans 2 échantillons testés de sang de patients leucémiques, mais toutes les tentatives d'isolement ont échoué. Nous avons travaillé à améliorer les conditions de culture des Gemmata. Notre analyse du génome de G. obscuriglobus et de G. massiliana a indiqué l'absence de certains composants essentiels dans la voie du métabolisme du fer, les sidérophores et l'enzyme ferriréductase. La culture des Gemmata en présence du surnageant filtré d'Escherichia coli contenant les sidérophores et l'enzyme ferriréductase, améliorait significativement la croissance des Gemmata par rapport à la culture sur une gélose standard. L'amélioration des techniques de culture nous permettra par la suite de mieux aborder l'étude de pathogénicité. / During our thesis work, we isolated a second Gemmata species; Gemmata massiliana from a hospital water network in France. We studied its distribution in two hospitals water network in Marseille after developing a real-time PCR. Filtered water collected at the intensive care unit and non-filtered water collected from dental chairs, tanks and usage points were tested. In total, 2.2% filtered water samples tested positive versus 11.3% non-filtered points, including 14.1% dental chairs, 5.9% usage points and 8% tank specimens. We concluded that hospitalized patients may be exposed to G. massiliana through hospital water, especially the non-filtered water. The role of Gemmata as opportunistic pathogen deserved to be explored. Additionally, using 16S rRNA gene-based specific Planctomycetes primers, enabled us to detect DNA Planctomycetes in 2 of 100 blood samples tested of leukemic patients. In one of the positive specimens DNA of a Gemmata-related bacterium was detected, unfortunately all isolation attempts proved futile. Therefore, we worked at improving the Gemmata species culture conditions to optimize their isolation from clinical samples. Genome analysis indicated that Gemmata organisms do not encode some essential iron pathway components, siderophores and ferric reductase. On this basis, we have shown that culture of G. obscuriglobus and G. massiliana in the presence of Escherichia coli filtered supernatant containing siderophores and extracellular ferric reductase, significantly improved the two species growth compared to their culture on a standard agar. The improvement of Gemmata species culture techniques will allow us to better address the pathogenicity study.

Orientador: Claudio Chrysostomo Werneck / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T08:25:27Z (GMT). No. of bitstreams: 1 Pereira_DanielleSousa_M.pdf: 8911447 bytes, checksum: c9bf5559a19db5c16b953e4b7a760966 (MD5) Previous issue date: 2014 / Resumo: MAGP1 (Microfibril-Associated GlycoProtein1) é um os constituintes das microfibrilas. Numerosos estudos têm demonstrado que MAGP1 interage com outras moléculas in vitro e sua expressão é de grande importância para o desenvolvimento vascular em zebrafish. Dados obtidos em nosso laboratório a partir do modelo fotoquímico de indução de trombo em animais deficientes em MAGP1 sugerem a importância deste componente da microfibrila no processo trombótico. Entre as técnicas para indução da formação de trombo, têm-se o cloreto férrico. Tal mecanismo, quando aplicado em pequenos animais, gera uma lesão endotelial de alta intensidade em apenas dois minutos. Além disso, com o auxílio da microscopia intravital, o cloreto férrico permite a captura de imagens do vaso sanguíneo em tempo real. A microscopia intravital possibilita a análise do processo de formação do trombo e as possíveis diferenças deste processo nos camundongos deficientes em MAGP1. Sendo assim, o presente trabalho objetivou estabelecer a técnica de trombose arterial induzida por cloreto férrico e assistida por microscopia intravital, a fim de verificar a função de MAGP1 no processo de formação do trombo. Para isto, as células brancas e as plaquetas de animais selvagens e deficientes em MAGP1 foram coradas com Rhodamina 6G e analisadas por microscopia intravital / Abstract: MAGP1 (Microfibril - Associated GlycoProtein1) is a constituent of the microfibrils. Numerous studies have shown that MAGP1 interact with other molecules in vitro and its expression is of importance for vascular development in zebrafish. Data obtained in our laboratory from the photochemical model of thrombus induction in animals deficient in MAGP1 suggest the importance of this component of the microfibril in the thrombotic process. Among the techniques for inducing thrombus formation, it has been ferric chloride. This mechanism when applied in small animals generates a high intensity endothelial injury in just two minutes. Furthermore, with the aid of intravital microscopy, ferric chloride enables the capture of blood vessel images in real time. The intravital microscopy allows the analysis of the process of thrombus formation and possible differences of this process in mice deficient in MAGP1. Therefore, this study aimed to establish the technique of arterial thrombosis induced by ferric chloride and assisted intravital microscopy, in order to verify the function of MAGP1 in the process of thrombus formation. For this, white cells and platelets MAGP1 deficient and wild animals were stained with Rhodamine 6G e analyzed by intravital microscopy / Mestrado / Bioquimica / Mestra em Biologia Funcional e Molecular

No description available.

No description available.

Fluoride in drinking water can lead to a crippling disease called fluorosis. As there is no cure for fluorosis, prevention is the only means of controlling the disease and research into fluoride remediation is critical. This work begins by providing a new approach to assessing fluoride remediation strategies using a combination of groundwater chemistry, saturation indices, and multivariate statistics based on the results of a large groundwater survey performed in a fluoride-contaminated region of India. From the Indian groundwater study, it was noted that one technique recommended for defluoridation involved using hydrous ferric oxide (HFO) as a solid phase sorbent for fluoride. This prompted investigation of bacteriogenic iron oxides (BIOS), a biogenic form of HFO, as a means of approaching bioremediation of fluoride. Batch sorption experiments at ionic strengths ranging from 0.001 to 0.1 M KNO3 and time course kinetic studies with BIOS and synthetic HFO were conducted to ascertain total sorption capacities (ST), sorption constants (Ks), and orders of reaction (n), as well as forward (kf) and reverse (kr) rate constants. Microcosm titration experiments were also conducted with BIOS and HFO in natural spring water from a groundwater discharge zone to evaluate fluoride sorption under field conditions. This thesis contributes significant, new information regarding the interaction between fluoride and BIOS, advancing knowledge of fluoride remediation and covering new ground in the uncharted field of fluoride bioremediation.

Dans cette thèse, nous démontrons des travaux sur la synthèse à faible coût des matériaux de cathode et l'anode pour les piles lithium-ion. Pour les cathodes, nous avons utilisé des précurseurs à faible coût pour préparer LiFePO4 et LiFe0.3Mn0.7PO4 en utilisant une méthode hydrothermale. Tout d'abord, des matériaux composites (LiFePO4/C) ont été synthétisés à partir d'un précurseur de Fe2O3 par une procédé hydrothermique pour faire LiFePO4(OH) dans une première étape suivie d'une calcination rapide pour le revêtement de carbone. Deuxièmement, LiFePO4 avec une bonne cristallinité et une grande pureté a été synthétisé en une seule étape, avec Fe2O3 par voie hydrothermale. Troisièmement, LiFe0.3Mn0.7PO4 a été préparé en utilisant Fe2O3 et MnO comme des précurseurs de bas coûts au sein d'une méthode hydrothermale synthétique. Pour les matériaux d'anode, nous avons nos efforts concentré sur un matériau d'anode à faible coût α-Fe2O3 avec deux types de synthèse hydrothermales, une a base de micro-ondes (MAH) l’autre plus conventionnelles (CH). La nouveauté de cette thèse est que pour la première fois le LiFePO4 a été préparé par une méthode hydrothermale en utilisant un précurseur Fe3+ (Fe2O3). Le Fe2O3 est un précurseur à faible coût et en combinant ses coûts avec les conditions de synthèse à basse température nous avons réalisé une réduction considérable des coûts de production pour le LiFePO4, menant ainsi à une meilleure commercialisation du LiFePO4 comme matériaux de cathode dans les piles lithium-ion. Par cette méthode de préparation, le LiFePO4/C procure une capacité de décharge et une stabilité de cycle accrue par rapport une synthétisation par la méthode à l'état solide pour les mêmes précurseurs Les résultats sont résumés dans deux articles qui ont été récemment soumis dans des revues scientifiques. / In this thesis, low cost syntheses of cathode and anode materials for lithium ion batteries will be presented. For cathode materials, low cost precursors were used to prepare LiFePO4 and LiFe0.3Mn0.7PO4 using low temperature hydrothermal method. Initially, a LiFePO4/C composite material was synthesized from a Fe2O3 precursor using a hydrothermal method to prepare LiFePO4(OH) in a first step followed by a fast calcination and carbon coating. Secondly, LiFePO4 with good crystallinity and high purity was synthesized, in one step, with nanometric sized Fe2O3 by a hydrothermal method. Thirdly, LiFe0.3Mn0.7PO4 was prepared using low cost Fe2O3 and MnO as precursors within a hydrothermal synthetic method. For anode materials, a low cost anode material α-Fe2O3 was prepared using two hydrothermal synthetic methods, microwave assisted (MAH) and conventional hydrothermal (CH). The novelty of the thesis is for the first time LiFePO4 has been prepared using a low cost Fe3+ precursor (Fe2O3) by a hydrothermal method. Low cost precursors and low temperature synthesis conditions will greatly reduce the synthetic cost of LiFePO4, leading to greater commercialization of LiFePO4 as a cathode materials for lithium-ion batteries. The as-prepared LiFePO4/C product provided enhanced discharge capacity and cycling stability compared to that synthesized using a solid state method with the same precursors. The results were summarized within two articles that were recently submitted to peer reviewed scientific journals.

Os reatores anaeróbios de concepção mais moderna (e.g., UASB e RALEx) possibilitam a remoção de 65 a 75% de matéria orgânica do esgoto sanitário, com custos de implantação e operação relativamente baixos, em comparação com os processos aeróbios convencionais. Entretanto, esses reatores geralmente são pouco eficientes na remoção de nutrientes e seus efluentes podem apresentar concentrações relativamente elevadas de material orgânico e de sólidos suspensos. Para melhorar a qualidade dos efluentes desses reatores, algumas configurações de pós-tratamento têm sido empregadas no Brasil, dentre as quais os sistemas de lodo ativado e a coagulação/precipitação com sais metálicos, geralmente seguida de flotação por ar dissolvido. Nesta pesquisa, foi avaliada a aplicabilidade da coagulação/precipitação com cloreto férrico, a partir de testes em unidades de coagulação em escala de bancada (jar test e flotateste), para três sistemas de pós-tratamento de efluentes de reatores anaeróbios, a saber: coagulação/precipitação do efluente de um reator anaeróbio (RALEx); co-precipitação em um sistema de lodo ativado; e pós-precipitação do efluente do sistema de lodo ativado. Cada um desses sistemas foi testado com separação de sólidos por sedimentação ou por flotação por ar dissolvido, constituindo seis distintas configurações de pós-tratamento. O pós-tratamento do efluente do reator anaeróbio por coagulação/precipitação se mostrou uma alternativa viável técnica e economicamente, tanto para a sedimentação quanto para a flotação por ar dissolvido. Os diagramas de coagulação obtidos tanto nos ensaios de sedimentação quanto nos de flotação demonstraram que a coagulação/precipitação do efluente do RALEx ocorria de modo mais eficiente para valores de pH entre 5 e 7. A coagulação/precipitação do licor misto com cloreto férrico também se mostrou uma opção atrativa, propiciando a obtenção de efluente bastante clarificado, com possibilidades de reúso. Nessa opção, obtiveram-se eficiências adicionais (i.e., em relação ao sobrenadante do licor misto) de remoção de turbidez, DQO e fósforo de, respectivamente, 80%, 72% e 85%, com dosagem de 80 mg de \'FE\'\'CL IND.3\'.6\'H IND.2\'O/L (48 mg de \'FE\'\'CL IND.3\'/L). Para a coagulação com cloreto férrico, a flotação não apresentou bons resultados na remoção de turbidez, DQO e fósforo para separação de sólidos do licor misto. O mesmo ocorreu para o efluente final da ETE quando a etapa de separação de sólidos foi a sedimentação. Quando a separação de sólidos foi feita por flotação, obtiveram-se eficiências de remoção de turbidez, DQO e fósforo de, respectivamente, 68%, 53% e 83%, com dosagem de 80 mg de \'FE\'\'CL IND.3\'.6\'H IND.2\'O/L / The anaerobic reactors of modern conception (e.g., UASB and RALEx) remove from 65 to 75% of sanitary wastewater organic matter with relatively low construction, operation, and maintenance costs, in comparison with conventional aerobic processes. Nevertheless, that reactors are usually little efficient in nutrient removal and their effluents may present relatively high organic matter and suspended solid concentrations. In order to improve the quality of effluents from anaerobic reactors, some post-treatment concepts have been employed in Brazil, among which activated sludge systems and coagulation/precipitation with metallic salts, generally followed by dissolved air flotation. In this research, coagulation/precipitation with ferric chloride was assessed using sedimentation and flotation lab-scale test units (jar test and flotateste, respectively) to three post-treatment systems, namely: coagulation/precipitation of effluent from anaerobic reactor; co-precipitation (in the mixed liquor from activated sludge system); and post-precipitation of effluent from activated sludge system. Each system was assessed with solids separation with sedimentation and dissolved air flotation, constituting six different post-treatment scenarios. Coagulation/precipitation of the effluent from the anaerobic reactor showed to be technical and economically attractive, not only for sedimentation but also for dissolved air flotation. Coagulation diagrams obtained in sedimentation and flotation essays showed that coagulation/precipitation of the effluent from RALEX was more efficient when pH values were between 5 and 7. The mixed liquor coagulation/flocculation with ferric chloride were also an attractive option, resulting in a low turbidity effluent suitable for reuse. In this option, additional removals (i.e., in relation to decanted mixed liquor) of turbidity, COD e phosphorus were obtained: 80%, 72% and 85%, respectively, with the dosage of 80 mg \'FE\'\'CL IND.3\'.6\'H IND.2\'O/L (48 mg \'FE\'\'CL IND.3\'/L). Flotation did not presented good results in the removal of turbidity, COD and phosphorus in mixed liquor coagulation/precipitation with ferric chloride. The same was to the effluent from the WWTP when sedimentation was employed in the solids separation step. When solids separation was made using flotation, the removal efficiencies of turbidity, COD and phosphorus were, respectively, 68%, 53%, and 83% for the dosage of 80 mg \'FE\'\'CL IND.3\'.6\'H IND.2\'O/L

Dans cette thèse, nous démontrons des travaux sur la synthèse à faible coût des matériaux de cathode et l'anode pour les piles lithium-ion. Pour les cathodes, nous avons utilisé des précurseurs à faible coût pour préparer LiFePO4 et LiFe0.3Mn0.7PO4 en utilisant une méthode hydrothermale. Tout d'abord, des matériaux composites (LiFePO4/C) ont été synthétisés à partir d'un précurseur de Fe2O3 par une procédé hydrothermique pour faire LiFePO4(OH) dans une première étape suivie d'une calcination rapide pour le revêtement de carbone. Deuxièmement, LiFePO4 avec une bonne cristallinité et une grande pureté a été synthétisé en une seule étape, avec Fe2O3 par voie hydrothermale. Troisièmement, LiFe0.3Mn0.7PO4 a été préparé en utilisant Fe2O3 et MnO comme des précurseurs de bas coûts au sein d'une méthode hydrothermale synthétique. Pour les matériaux d'anode, nous avons nos efforts concentré sur un matériau d'anode à faible coût α-Fe2O3 avec deux types de synthèse hydrothermales, une a base de micro-ondes (MAH) l’autre plus conventionnelles (CH). La nouveauté de cette thèse est que pour la première fois le LiFePO4 a été préparé par une méthode hydrothermale en utilisant un précurseur Fe3+ (Fe2O3). Le Fe2O3 est un précurseur à faible coût et en combinant ses coûts avec les conditions de synthèse à basse température nous avons réalisé une réduction considérable des coûts de production pour le LiFePO4, menant ainsi à une meilleure commercialisation du LiFePO4 comme matériaux de cathode dans les piles lithium-ion. Par cette méthode de préparation, le LiFePO4/C procure une capacité de décharge et une stabilité de cycle accrue par rapport une synthétisation par la méthode à l'état solide pour les mêmes précurseurs Les résultats sont résumés dans deux articles qui ont été récemment soumis dans des revues scientifiques. / In this thesis, low cost syntheses of cathode and anode materials for lithium ion batteries will be presented. For cathode materials, low cost precursors were used to prepare LiFePO4 and LiFe0.3Mn0.7PO4 using low temperature hydrothermal method. Initially, a LiFePO4/C composite material was synthesized from a Fe2O3 precursor using a hydrothermal method to prepare LiFePO4(OH) in a first step followed by a fast calcination and carbon coating. Secondly, LiFePO4 with good crystallinity and high purity was synthesized, in one step, with nanometric sized Fe2O3 by a hydrothermal method. Thirdly, LiFe0.3Mn0.7PO4 was prepared using low cost Fe2O3 and MnO as precursors within a hydrothermal synthetic method. For anode materials, a low cost anode material α-Fe2O3 was prepared using two hydrothermal synthetic methods, microwave assisted (MAH) and conventional hydrothermal (CH). The novelty of the thesis is for the first time LiFePO4 has been prepared using a low cost Fe3+ precursor (Fe2O3) by a hydrothermal method. Low cost precursors and low temperature synthesis conditions will greatly reduce the synthetic cost of LiFePO4, leading to greater commercialization of LiFePO4 as a cathode materials for lithium-ion batteries. The as-prepared LiFePO4/C product provided enhanced discharge capacity and cycling stability compared to that synthesized using a solid state method with the same precursors. The results were summarized within two articles that were recently submitted to peer reviewed scientific journals.

Over the past decade, the objectives for coagulation based drinking water treatment processes have changed significantly. These changes are a result of stringent goals related to natural organic matter (NOM) removal to mitigate the formation of subsequent harmful and health-related disinfection by-products (DBPs) and the need to achieve adequate filtration performance to ensure sufficient particle removal for pathogen control. Another concern associated with coagulation optimization is the potential unintended consequences of a coagulant change on the distribution system, specifically related to lead release from lead pipe and solder materials. Optimizing these multi-objectives in a direct filtration treatment process presents significant challenges for source waters characterized by low levels of turbidity, alkalinity and organic matter content. Bench and pilot-scale experiments were conducted to evaluate the performance of ferric sulfate, polyaluminum chloride (PACl) and aluminum chlorohydrate (ACH) against aluminum sulfate (alum) using variable coagulation dosage and pH conditions for a direct filtration facility. Bench-scale experiments were conducted to optimize NOM removal during coagulation using traditional organic matter surrogates coupled with molecular size characterization techniques. Pilot-scale studies provided a snapshot of feasibility in terms of filtration performance for favourable bench-scale conditions and also identified optimal conditions for filtration performance. Results from pilot testing demonstrated that favourable conditions identified for increased potential NOM removals during bench-scale testing were significantly different than optimal filtration conditions identified during pilot studies; and, in fact, severely compromised direct filtration performance due to increased solids loading to the filters. Bench-scale experiments evaluated lead leaching from lead and lead:tin solder galvanically connected to copper under stagnant conditions using variable chloride-to-sulfate mass ratio (CSMR) conditions for alum, ferric sulfate and PACl. Although recent research identifies high CSMRs (>0.5) as the main mechanism of attack in distribution systems following coagulant changeovers, CSMR was not the primary catalyst for lead leaching following the coagulant changeover conditions evaluated in this study. Residual concentrations of iron and aluminum remaining following coagulation were the principal contributors. Positive correlations were revealed between particulate iron and particulate lead concentrations following stagnation demonstrating that the adsorption of lead to iron oxides is a viable hypothesis for lead release.