Made available in DSpace on 2017-07-20T13:41:57Z (GMT). No. of bitstreams: 1 Luiz Fernando Wagner.pdf: 2111456 bytes, checksum: e1870a4be2fbc8c765b6f4d6b0077dbe (MD5) Previous issue date: 2015-03-23 / The disposal of wastes generated in water treatment plants (WTP) by launching into water streams is considered an environmental crime by current Brazilian law and became one of the challenges of drinking water public companies, nowadays. The objective of this study was to analyze the alternative disposal of decanter’s sludge from a WTP, with microsand ballasted sedimentation (ActifloÒ), in a wastewater treatment plant (WWTP) containing upflow anaerobic sludge blanket reactors (UASB) and polishing pond, called WWTP Verde, in the city of Ponta Grossa - PR, through the sewage collection network. The treatment evaluation on the WWTP was performed for seven distinct phases. The phase 1 occurred with WWTP receiving only sewage. Phases 2 to 7 occurred with release of WTP sludge in continuous periods ranging from 4 hours per day (phase 2) to 24 hours per day (phase 7),reaching the percentage of 3.2% of WTP sludge, in relation to the total volume tributary to WWTP. The WWTP operated in stable condition throughout the period,with an average flow tributary of 213.14 L/s. The UASBs operated with HRT in 9.9 hours, VHL in 2.4 m3/m3/d, and OLR ranging from 0.75 to 1.66 kgCOD/m3/d. The polishing pond operated with HRT in 4.5 days and OLR ranging from 765 to 2872 kgCOD/ha/d, which corresponds from 19 to 72 gCOD/m3/d. The removal efficiency of COD and TSS by UASBs and the pond was maintained even with the release of WTP sludge. The overall efficiency of the WWTP ranged between 80% and 86% for COD removal and between 92% and 96% for the TSS removal. It was observed greater removal of nitrogen and phosphorus by UASBs and higher concentration ofnitrogen, phosphorus, potassium and magnesium in the UASB's sludge, in the period in which the WWTP was operated with the WTS sludge release. It was concluded that the sludge release in the sewage collection network is a viable alternative to disposal of the decanter's waste of WTP Actiflo®, not precluding the treatment of sewage in WWTP Verde and the use of sewage sludge in agriculture. However, can be necessary increase the UASB's sludge extraction frequency, from 16 hours of continuous duration of WTP sludge release in the sewage collection network. / A disposição dos resíduos gerados nas estações de tratamento de água (ETA) através do lançamento in natura em corpos d’água é considerada crime ambiental pela legislação brasileira vigente e passou a ser um dos desafios das companhias de abastecimento público de água, na atualidade. O objetivo deste trabalho foi analisar a alternativa de disposição do lodo do decantador de uma ETA, com sedimentação lastreada por microareia (ActifloÒ), em uma estação de tratamento de esgotos (ETE) composta de reatores anaeróbios de leito fluidizado (RALFs) e lagoa de polimento, denominada ETE Verde, no município de Ponta Grossa – PR, através da rede coletora de esgotos. A avaliação do tratamento da ETE foi feita durante sete fases distintas. A fase 1 ocorreu com a ETE recebendo apenas esgoto sanitário. As fases 2 a 7 ocorreram com lançamentos de lodo de ETA, em períodos contínuos que variaram desde 4 horas por dia (fase 2) até 24 horas por dia (fase 7), chegando ao percentual de 3,2% de lodo de ETA, em relação ao volume total afluente à ETE. A ETE operou em condição estável durante todo o período, com uma vazão média afluente de 213,14 L/s. Os RALFs operaram com TDH de 9,9 horas, CHV de 2,4 m3/m3/d e COV aplicada variando entre 0,75 e 1,66 kgDQO/m3/d. A lagoa operou com TDH de 4,5 dias, com TAS variando entre 765 e 2872 kgDQO/ha/d e COV aplicada variando entre 19 e 72 gDQO/m3/d. A eficiência na remoção de DQO e SST pelos RALFs e pela lagoa foi mantida, mesmo com o lançamento do lodo da ETA. A eficiência global da ETE variou entre 80% e 86% para a remoção de DQO e entre 92% e 96% para a remoção de SST. Foi observada maior remoção de nitrogênio e fósforo pelos RALFs e maior concentração de nitrogênio, fósforo, potássio e magnésio no lodo dos RALFs, no período em que a ETE operou com o lançamento do lodo de ETA. Concluiu-se que o lançamento do lodo na rede de esgotos é uma alternativa viável de disposição dos rejeitos do decantador da ETA Actiflo®, não inviabilizando o tratamento de esgotos na ETE Verde e o uso do lodo do esgoto na agricultura. Porém, pode ser necessário aumentar a frequência de extração do lodo dos RALFs, a partir de 16 horas diárias de duração contínua de lançamento de lodo de ETA na rede coletora de esgotos.

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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.