Métodos de Microbiologia de anaeróbios estritos e de Biologia Molecular foram empregados para se conhecer a diversidade de microrganismos relacionados à degradação de ascarel em reatores anaeróbios metanogênicos. A avaliação de potencial metanogênico foi realizada para a escolha da melhor condição nutricional, bem como, para a seleção de material suporte e solvente adequado a solubilização do ascarel. Nos ensaios em batelada, a produção de metano foi maior nos reatores contendo etanol (média de 0,22 - 0,46 molCH4/gSTV, 46h). Remoção de 85,6% (86,7 mg/L de PCB em Aroclor 1016 e 1260) foi obtida na condição com espuma de poliuretano, etanol (46g/L) e formiato (680 mg/L). Diferentes solventes e surfactantes, tais como, DMSO, dioxano, ácido acético, ácido fórmico, n-hexano, acetona, etano, metanol, Tween 80, SDS (10%) e Triton X-100 foram avaliados para a solubilização de ascarel. Dentre esses, metanol, Triton X-100 e ácido fórmico foram eleitos para a realização de ensaio em reatores em batelada contendo espuma de poliuretano, com o propósito de avaliar o potencial metanogênico na degradação de PCB. Os valores de produção de metano foram muito semelhantes (0,21 0,38 molCH4/mLgSTV, 45h) nas diferentes condições, no entanto, a remoção de PCB foi maior nos reatores com metanol 790 mg/L (86,6%), ácido Fórmico 600 mg/L (84,5%) e Triton X-100 1% (72,1%). Portanto, a melhor condição foi contemplada para a operação do reator anaeróbio horizontal de leito fixo (RAHLF) no tratamento do ascarel, ou seja, células imobilizadas em espuma de poliuretano, etanol e formiato (como fonte de carbono), Triton X-100 (0,1%) e metanol (como solvente). No RAHLF, a remoção média de matéria orgânica (DQO) foi de 91% para concentração afluente média de 1270 mg/L. A presença de morfologias semelhantes à Methanosarcina e bacilos fluorescentes foi confirmada em exames microscópicos. Na análise filogenética, por meio de PCR/DGGE e seqüenciamento das bandas recortadas, os grupos encontrados foram relacionados aos Filos Proteobacteria, Firmicutes, Spirochaetes, Chlorobi e Chloroflexi, sendo que neste último estão incluídos representantes relacionados a degradação de PCBs. Dentre as arquéias metanogênicas verificou-se similaridade de 99% e 97% com Methanosaeta sp. e Methanolinea sp., relacionadas com a metanogenese acetoclástica e hidrogenotrófica, respectivamente / Molecular biology and microbiology methods were used to study the microbial communities related to degradation of ascarel at methanogenic conditions in an anaerobic reactor. The methanogenic potential was evaluated to choose the better nutritional condition as well as to select the better support material and the most suitable solvent to favor the solubilization of ascarel. The methane production was higher (0.22 0.46 molCH4/mLgSTV, 46h) in batch reactors containing ethanol (46 g/L) and formate (680 mg/L), the PCB elimination attaining 85.6% (86.7 mg/L de PCB as Aroclor 1016 and 1260) when Polyuretane foam was used as support material. Different solvents, namely DMSO, dioxane, n-hexane, acetic acid, formic acid, acetone, ethane, methanol, and surfactants, such as 10% SDS,, Triton X-100, were evaluated aiming o determine the better condition to solubilize ascarel. According to the results of such experiments, methanol, formic acid and Triton X-100 were selected for carrying out the batch experiments in reactors containing polyurethane foam to evaluate the methane production during the PCBs degradation. Regardless of the operation conditions the methane production rates were similar (0.21 0.38 molCH4/gSTV, 45h), however the elimination of PCB was higher in the reactors containing methanol (790 mg/L), formic acid (600 mg/L) and Triton X-100 (1%). Therefore, the better condition for treating ascarel-containing residues in a bench-scale horizontal-flow immobilized biomass (HAIB) was attained with cells immobilized in polyurethane foam when ethanol and formate were used as carbon sources, and in presence of Triton X-100 and methanol, the average elimination of organic material attaining 91% for affluent concentration of 1270 mg/L. The presence of Methanosarcina and fluorescent rods was confirmed by microscopy analysis. According to the filogenetics analysis, which was carried out by PCR/DGGE and band-sequencing, the Bacteria domain are related to the Filos Proteobacteria, Firmicutes, Spirochaetes, Chlorobi and Chloroflexi, this latter being directly related to the degradation of PCB. Among the methanogenic Archea, a similiraty of 99% and 97% was observed to Methanosaeta sp. and Methanolinea sp. related to acetoclastic and hydrogenthrophic methanogenesis, respectively

O objetivo deste trabalho foi avaliar o desempenho da remoção de cistos deGiardia spp. e oocistos de Cryptosporidium parvum, em águas de abastecimento com turbidez elevada, em experimentos em escala de bancada (coagulação, floculação, decantação e filtração). Para tanto, empregou-se o coagulante cloreto de polialumínio – PAC. O método de filtração em membranas foi adotado para a concentração de protozoários, seguido ou não da etapa de purificação por separação imunomagnética – IMS. Os métodos foram avaliados em experimentos de controle de qualidade analítica e o método sem IMS apresentou as seguintes porcentagens de recuperação, 80% ±16,32% para cistos de Giardia spp. e 5% ±10,00% para oocistos de C. parvum. O método com IMS apresentou 31,5%±7,55% de recuperação para cistos de Giardia spp. e 5,75%±3,20% de recuperação para oocistos de C. parvum. Os experimentos demonstraram que não houve melhora na remoção de ambos os protozoários na condição de maior dosagem de coagulante (65 mg.L-1 de PAC e pH 7,29). A condição de menor dosagem de coagulante (25 mg.L-1 de PAC e pH 6,76) apresentou um desempenho melhor, ao contrário de uma expectativa de que a maior dosagem de coagulante pudesse favorecer a remoção destes microrganismos. A condição de menor dosagem apresentou, na água filtrada, 50 e 75% de ausência de identificação de cistos de Giardia e oocistos de C. parvum, respectivamente. A condição de maior dosagem apresentou (oo)cistos na água filtrada de todas amostras analisadas. Estes resultados indicam a importância do controle da coagulação na remoção de protozoários. / The aim of this study was to evaluate the performance of Giardia spp. cysts and Cryptosporidium parvum oocysts removal in a bench scale experiment. The coagulant polyaluminium chloride – PACl was used in this research. The protozoa concentration tests were performed by applying the Membrane Filtration method, with and without Immunomagnetic Separation assay-IMS. The methods were evaluated using control experiments and the method without IMS had the following percentage recovery, 80% ± 16.32% and 5% ±10.00% for Giardia cysts and C. parvum oocysts, respectively. The method with IMS presented 31.5% ± 7.55% and 5.75% ± 3.20% of percentage recovery for Giardia cysts and C. parvum oocysts, respectively. Bench scale experimental results have clearly shown that there was no improvement in protozoa removal using the superior dosage of coagulant. The inferior dosage condition (25 mg.L-1 of PACl and pH 6,76) performed better, which was contrary to what was expected in which a superior dosage of coagulant could favour when removing microorganisms. The inferior dosage condition presented 50% and 75% of absence of Giardia cysts and C. parvum oocysts in the final water, respectively. The second coagulation condition (65 mg.L-1 of PACl and pH 7,29) presented protozoa (oo)cysts in the final water of all the samples examined. These results indicate the importance of coagulation control in protozoa removal.

O objetivo deste trabalho foi avaliar o desempenho da remoção de cistos deGiardia spp. e oocistos de Cryptosporidium parvum, em águas de abastecimento com turbidez elevada, em experimentos em escala de bancada (coagulação, floculação, decantação e filtração). Para tanto, empregou-se o coagulante cloreto de polialumínio – PAC. O método de filtração em membranas foi adotado para a concentração de protozoários, seguido ou não da etapa de purificação por separação imunomagnética – IMS. Os métodos foram avaliados em experimentos de controle de qualidade analítica e o método sem IMS apresentou as seguintes porcentagens de recuperação, 80% ±16,32% para cistos de Giardia spp. e 5% ±10,00% para oocistos de C. parvum. O método com IMS apresentou 31,5%±7,55% de recuperação para cistos de Giardia spp. e 5,75%±3,20% de recuperação para oocistos de C. parvum. Os experimentos demonstraram que não houve melhora na remoção de ambos os protozoários na condição de maior dosagem de coagulante (65 mg.L-1 de PAC e pH 7,29). A condição de menor dosagem de coagulante (25 mg.L-1 de PAC e pH 6,76) apresentou um desempenho melhor, ao contrário de uma expectativa de que a maior dosagem de coagulante pudesse favorecer a remoção destes microrganismos. A condição de menor dosagem apresentou, na água filtrada, 50 e 75% de ausência de identificação de cistos de Giardia e oocistos de C. parvum, respectivamente. A condição de maior dosagem apresentou (oo)cistos na água filtrada de todas amostras analisadas. Estes resultados indicam a importância do controle da coagulação na remoção de protozoários. / The aim of this study was to evaluate the performance of Giardia spp. cysts and Cryptosporidium parvum oocysts removal in a bench scale experiment. The coagulant polyaluminium chloride – PACl was used in this research. The protozoa concentration tests were performed by applying the Membrane Filtration method, with and without Immunomagnetic Separation assay-IMS. The methods were evaluated using control experiments and the method without IMS had the following percentage recovery, 80% ± 16.32% and 5% ±10.00% for Giardia cysts and C. parvum oocysts, respectively. The method with IMS presented 31.5% ± 7.55% and 5.75% ± 3.20% of percentage recovery for Giardia cysts and C. parvum oocysts, respectively. Bench scale experimental results have clearly shown that there was no improvement in protozoa removal using the superior dosage of coagulant. The inferior dosage condition (25 mg.L-1 of PACl and pH 6,76) performed better, which was contrary to what was expected in which a superior dosage of coagulant could favour when removing microorganisms. The inferior dosage condition presented 50% and 75% of absence of Giardia cysts and C. parvum oocysts in the final water, respectively. The second coagulation condition (65 mg.L-1 of PACl and pH 7,29) presented protozoa (oo)cysts in the final water of all the samples examined. These results indicate the importance of coagulation control in protozoa removal.

Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children. The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production. Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer. The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques. The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal. Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L). Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%. Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.

Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children. The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production. Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer. The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques. The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal. Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L). Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%. Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.