Por meio das mudanças de paradigmas relacionados à gestão ambiental e elevação dos custos de lançamento de efluente, captação e tratamento de água, as indústrias passam por processos de inovação que resultam em melhor utilização dos recursos e maior diminuição dos custos. Além disso, as empresas estão sujeitas a maiores exigências quanto à legislação ambiental vigente impulsionando-as a implantar sistemas de reúso de efluentes. Apesar de representar uma importante atividade econômica, a indústria de laticínios é responsável pela geração de efluentes líquidos com alto potencial poluidor. O presente trabalho teve como objetivo a redução de contaminantes e melhoria da biodegradabilidade de efluentes de laticínios utilizando tratamentos combinados, em destaque, coagulação/floculação, processos com membranas e oxidação/redução química fotocatalítica. Os efluentes foram provenientes de uma indústria da região, oriundos da etapa de nanofiltração do soro ultrafiltrado. Eles foram divididos em duas correntes, denominadas de concentrado de nanofiltração (corrente 1) e permeado de nanofiltração (corrente 2). Para o tratamento da corrente 1 foi proposto inicialmente coagulação/floculação utilizando diferentes agentes coagulantes naturais (quitosana, derivado de tanino e extrato de moringa), seguido do uso de processos com membranas do tipo microfiltração (0,40 ?m em polieterimida) e ultrafiltração (50 kDa em polietersulfona). Para a corrente 2 foi proposto a utilização de Processos Oxidativos e Redutivos Avançados. Em todas as etapas foi utilizada a Metodologia da Superfície de Resposta para identificação das condições otimizadas. Para o tratamento de coagulação/floculação da corrente 1 foram avaliadas as influências do pH, dos coagulantes naturais e da agitação sobre as variáveis resposta reduções de carbono orgânico total (COT), demanda química de oxigênio (DQO) e turbidez. Na condição indicada como ótima foram alcançadas reduções de 18,3% de COT, 12,7% de DQO e 19,6% de turbidez. A partir da condição otimizada a corrente 1 foi submetida aos processos com membranas, sendo selecionada a microfiltração como melhor tratamento. O uso dessas membranas possibilitou reduções de 1,25% em COT, 5,21% em DQO e 87,4% em turbidez. A combinação destas tecnologias possibilitou a eliminação de 20,1%, 18,0%, 89,8% em COT, DQO e turbidez, respectivamente. Para o tratamento da corrente 2 foram utilizados diferentes tipos de processos oxidativos avançados sendo eles, foto-Fenton (íons ferrosos) e foto-Fenton avançado (uso de ferro metálico). Nestes casos foram avaliadas a influência das concentrações de peróxido de hidrogênio e íon ferroso e ferro metálico considerando como variáveis resposta reduções de COT e DQO. Os resultados otimizados obtidos para o POA foto-Fenton permitiram reduções de 89,9% em COT e 50,8% em DQO, enquanto os resultados otimizados para POA foto-Fenton avançado foram reduções de 74,9% de COT e 41,0% de DQO. / Through the paradigm changes related to environmental management and rising costs of effluent discharge, water abstraction and treatment, industries undergo innovation processes that result in better use of resources and greater reduction in costs. Moreover, companies are submitted to greater requirements regarding environmental regulations driving them to deploy reuse of wastewater systems. Despite representing an important economic activity, the dairy industry is responsible for producing wastewater with high pollution potential. The present work was carried out in order to reduce contaminants and improve the biodegradability of dairy effluent by using an hybrid wastewater treatment based on coagulation/flocculation, membrane process and photocatalytic chemical oxidation/reduction. The effluents came from a regional industry and originating from the nanofiltration step of an ultrafiltrate whey. They were divided into two streams, called nanofiltration concentrate (stream 1) and nanofiltration permeate (stream 2). For the treatment of stream 1 was initially proposed coagulation/flocculation using different natural coagulant agents (chitosan, derivative tannin and moringa extract), followed by membrane processes type of microfiltration (0.40 ?m in polyetherimide) and ultrafiltration (50 kDa in polyethersulfone). For the stream 2 Advanced Oxidation and Reductive Processes were performed. In all steps of the work Response Surface Methodology was used to identify the optimum conditions. For the coagulation/flocculation treatment, the influence of the pH, natural coagulants and agitation were evaluated on the response variables total organic carbon (TOC), chemical oxygen demand (COD) and turbidity reductions. The optimized results reduced of 18.3% TOC, 12.7% COD and 19.6% turbidity. From the indicated condition stream 1 was submitted to membrane processes, being selected the microfiltration as the best treatment. The use of theses membranes provided 1.25% TOC, 5.21% COD and 87.4% turbidity reductions. The combination of these technologies has enabled the elimination of 20.1%, 18.0%, 89.8% in TOC, COD and turbidity, respectively. For the treatment of the stream 2 different types of Advanced Oxidation Processes were used being them, photo-Fenton (ferrous ions) and advanced photo-Fenton (metallic iron). In this cases the influence of the hydrogen peroxide, ferrous ion and metallic iron concentrations were evaluated, considering as response variables TOC and COD reductions. The optimized results for the photo-Fenton AOP allowed 89.9% TOC and 50.8% COD reductions, while the results optimized for advanced photo-Fenton AOP were 74.9% TOC and 41.0% COD reductions.

Abstract Chemical treatment is considered best available technology for purification of peat extraction runoff in Finland, due to its capability to remove dissolved organic carbon (DOC), suspended solids and nutrients. However, lack of optimisation and adaptation of this method for purification of diffuse pollution sources, e.g., peat extraction runoff, has led to significant fluctuations in purification efficiency. This thesis evaluated the suitability of commercially available coagulants for the treatment of typically humic water. Inorganic (ferric sulphate, aluminium sulphate and a mixed product) and organic (polyDADMAC, polyamine, chitosan and tannin products) coagulants were studied. Investigations included assessment of required dosage and the influence of process parameters (pollutant concentration, mixing, water pH and temperature) on coagulant performance. In addition, the process conditions in existing treatment systems were examined in field experiments aimed at identifying possible factors affecting purification. Ferric sulphate (FS) was the most effective of the coagulants tested. It produced excellent flocs and achieved higher removal efficiency, particularly for DOC, than the other coagulants. However, the dosage required for FS was significantly higher than for e.g., polyDADMAC and chitosan. Moreover, samples treated with FS displayed high iron concentration and acidic pH. The organic polymers achieved satisfactory results, but further research is needed before they can become viable alternatives to metal salts. The quality of peat extraction runoff water was found to vary significantly. It was also observed that variations in DOC concentration, even for particulate rich samples, controlled coagulant dosage and, consequently, treatment efficiency. For inorganic coagulants, mixing provided during flocculation had a more significant influence on purification than mixing provided during coagulation. This is relevant hence in now existing treatment facilities no mixing is employed during flocculation. Based on the research conducted, suggestions were formulated for process optimisation aimed at reducing variations in purification efficiency, thus increasing the reliability of the method and reducing related environmental impacts. / Tiivistelmä Turvetuotannon valumavesien käsittelyssä yksi parhaista käyttökelpoisistatekniikoista on kemiallinen käsittely, koska se pystyy poistamaan valumavedestä liukoista orgaanista hiiltä (DOC), kiintoainetta ja ravinteita. Tästä huolimatta kemiallisen käsittelyn optimointia ei ole tehty hajakuormitukselle, kuten turvetuotannon valumavesille, minkä seurauksena valumavesien puhdistustuloksissa on suurta vaihtelua. Tässä väitöstyössä tutkittiin markkinoilla saatavilla olevien kemikaalien sopivuutta turvetuotannon humuspitoisille valumavesille. Tutkimuksessa testattiin epäorgaanisia (ferrisulfaatti, alumiinisulfaatti ja näiden sekoitus) ja orgaanisia (polyDADMAC, polyamiini, kitosaani ja tanniinipohjaisia polymeerejä) koagulanttikemikaaleja. Tutkimuksessa selvitettiin koagulanttien annostarpeet sekä erilaisten prosessiparametrien (vedenlaatu, sekoittaminen, pH ja lämpötila) vaikutus koagulanttien toimintaan. Laboratoriotutkimusten lisäksi väitöstyö sisälsi kenttämittauksia turvetuotannon valumavesien tyypillisten kemiallisen vesienkäsittelyn prosessiparametrien selvittämiseksi. Tutkituista koagulanteista rautasulfaatti oli tehokkain. Se tuotti hyvin laskeutuvaa flokkia ja poisti parhaiten valumavesien orgaanista ainesta. Rautasulfaatti vaati kuitenkin selkeästi suuremman annostuksen kuin esimerkiksi polyDADMAC ja kitosaani. Lisäksi puhdistettuun veteen jäi paljon rautaa ja vesi oli hapanta. Orgaanisilla kemikaaleilla saavutettiin myös kohtalainen/melko hyvä puhdistustulos, mutta lisää tutkimusta tarvitaan ennen kuin ne voivat olla vaihtoehtona epäorgaanisille kemikaaleille. Turvetuotannon valumaveden laatu vaihteli paljon. Valumaveden orgaanisen aineen määrän vaihtelulla oli suurin vaikutus kemikaalin annostukseen ja puhdistustulokseen. Sekoituksista kemiallisen käsittelyn flokkulaatiovaiheen sekoituksella oli suurempi vaikutus puhdistustulokseen kuin koagulaatiovaiheen sekoituksella. Tutkituilla turvetuotantoalueilla ei kuitenkaan ollut tällä hetkellä riittävää sekoitusta flokkulaatiovaiheessa. Tässä väitöstyössä esitetään parannuksia kemiallisen käsittelyn optimointiin paremman ja vakaamman puhdistustuloksen aikaansaamiseksi humuspitoisille vesille.

The freshwater dinoflagellate species, Ceratium hirundinella (C. hirundinella) possesses unique characteristics, such as a thecal-plate cell covering of cellulose, spines and flagella. Unlike most other algae and cyanobacteria, C. hirundinella cells are relatively large in size (up to 450 μm in length and 50 μm in width). These unique characteristics (e.g. cell covering and flagella) and adaptations (e.g. spines) give the dinoflagellate cells the ability to reduce their sinking rate from the euphotic zone and to migrate easily through the water column. When source water contains high concentrations of C. hirundinella cells, water treatment problems and poor aesthetic water quality can be expected. These water treatment problems may include 1) the disruption of coagulation and flocculation, 2) clogging of sand filters and 3) taste and odour problems when cells penetrate into the final water. In Chapter 9 of this study, a list of operational guidelines (including alert levels) and recommendations to assist managers and operators of plants when C. hirundinella cells are causing water treatment problems. During events of high C. hirundinella concentrations in source water, managers and operators of conventional water treatment plants need strategies to optimize coagulants and unit processes. Thus when source water contains motile nuisance algae, such as C. hirundinella, in moderate or abundant quantities, it is advisable to conduct jar stirring test experiments using both turbidity and total photosynthetic pigment (or chlorophyll-a) analyses as indicators of appropriate coagulant choice and dosages. The aims of this study are summarized as follows:  To optimize coagulants and conventional water treatment processes by implementing relevant algal removal strategies and indicators during jar stirring test experiments,  To investigate the changes in surface charge (known as zeta potential) on C. hirundinella cells before and after adding coagulants as part of the treatment processes,  To investigate the physical and chemical impacts on the morphology of C. hirundinella cells after coagulation, flocculation and sedimentation,  To identify organic compounds that may be responsible for taste and odour problems associated with C. hirundinella,  To investigate the efficiency of pre-chlorination on the removal C. hirundinella cells when dosing various coagulants, and  Give recommendations and operational guidelines relevant for a conventional water treatment plant to improve C. hirundinella removal A combined water treatment system (Phipps and Bird Model), consisting of a six paddle jar test apparatus and six sand filter columns, was used to simulate conventional processes (coagulation, flocculation, sedimentation and rapid sand filtration). Source water samples containing relatively high C. hirundinella concentrations (> 500 cell/mℓ) were collected from Benoni Lake (26º10’50.40’’S; 28º17’50.11’’ E) in plastic containers and stored as a homogenous sample in a 200 litre container under laboratory conditions (± 22 °C). Samples were collected from the source water as well as after sedimentation (from the supernatant or sludge) to determine turbidity, total photosynthetic pigment analyses (chlorophyll) and for phytoplankton analyses. Flocs (containing C. hirundinella cells) were collected from the sludge or sediment for scanning electron microscopy investigations and to perform zeta potential analyses. Concentrated C. hirundinella samples were frozen at -80 °C according to the proposed sampling protocol for organic compound analyses. Results obtained from this study proved that using the relevant indicators to determine the appropriate coagulant dosages during jar stirring tests may generally improve the removal of problem-causing algae, such as C. hirundinella cells. Improved algal removal efficiencies will subsequently ensure final water with good aesthetic quality. The surface charge (zeta potential) on C. hirundinella cells can be used to evaluate the best coagulation conditions within an operating window of -10 mV to +3 mV when dosing various coagulants. Scanning electron microscopy investigations revealed major damaging effects to C. hirundinella cells when dosing high Ca(OH)2 concentrations. However, when dosing lower Ca(OH)2 concentrations, in combination with organic polymer, better C. hirundinella cell removal efficiencies with less damaging effects to cells was observed. This study also indicated that the pre-chlorination, without causing cell lyses, can be applied to render the highly motile cells immobile which will subsequently assist the coagulation unit process. The aesthetic quality (e.g. tastes and odours) of drinking water may be influenced when C. hirundinella cells release organic material into the water as a result of cell lyses. Organic compounds, such as fatty acids and dicarboxylic acids can lead to taste and odour problems which associate with the presence of C. hirundinella. Organic compounds also serve as precursors for the formation of harmful chlorine by-products formed during chlorination. / PhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

The freshwater dinoflagellate species, Ceratium hirundinella (C. hirundinella) possesses unique characteristics, such as a thecal-plate cell covering of cellulose, spines and flagella. Unlike most other algae and cyanobacteria, C. hirundinella cells are relatively large in size (up to 450 μm in length and 50 μm in width). These unique characteristics (e.g. cell covering and flagella) and adaptations (e.g. spines) give the dinoflagellate cells the ability to reduce their sinking rate from the euphotic zone and to migrate easily through the water column. When source water contains high concentrations of C. hirundinella cells, water treatment problems and poor aesthetic water quality can be expected. These water treatment problems may include 1) the disruption of coagulation and flocculation, 2) clogging of sand filters and 3) taste and odour problems when cells penetrate into the final water. In Chapter 9 of this study, a list of operational guidelines (including alert levels) and recommendations to assist managers and operators of plants when C. hirundinella cells are causing water treatment problems. During events of high C. hirundinella concentrations in source water, managers and operators of conventional water treatment plants need strategies to optimize coagulants and unit processes. Thus when source water contains motile nuisance algae, such as C. hirundinella, in moderate or abundant quantities, it is advisable to conduct jar stirring test experiments using both turbidity and total photosynthetic pigment (or chlorophyll-a) analyses as indicators of appropriate coagulant choice and dosages. The aims of this study are summarized as follows:  To optimize coagulants and conventional water treatment processes by implementing relevant algal removal strategies and indicators during jar stirring test experiments,  To investigate the changes in surface charge (known as zeta potential) on C. hirundinella cells before and after adding coagulants as part of the treatment processes,  To investigate the physical and chemical impacts on the morphology of C. hirundinella cells after coagulation, flocculation and sedimentation,  To identify organic compounds that may be responsible for taste and odour problems associated with C. hirundinella,  To investigate the efficiency of pre-chlorination on the removal C. hirundinella cells when dosing various coagulants, and  Give recommendations and operational guidelines relevant for a conventional water treatment plant to improve C. hirundinella removal A combined water treatment system (Phipps and Bird Model), consisting of a six paddle jar test apparatus and six sand filter columns, was used to simulate conventional processes (coagulation, flocculation, sedimentation and rapid sand filtration). Source water samples containing relatively high C. hirundinella concentrations (> 500 cell/mℓ) were collected from Benoni Lake (26º10’50.40’’S; 28º17’50.11’’ E) in plastic containers and stored as a homogenous sample in a 200 litre container under laboratory conditions (± 22 °C). Samples were collected from the source water as well as after sedimentation (from the supernatant or sludge) to determine turbidity, total photosynthetic pigment analyses (chlorophyll) and for phytoplankton analyses. Flocs (containing C. hirundinella cells) were collected from the sludge or sediment for scanning electron microscopy investigations and to perform zeta potential analyses. Concentrated C. hirundinella samples were frozen at -80 °C according to the proposed sampling protocol for organic compound analyses. Results obtained from this study proved that using the relevant indicators to determine the appropriate coagulant dosages during jar stirring tests may generally improve the removal of problem-causing algae, such as C. hirundinella cells. Improved algal removal efficiencies will subsequently ensure final water with good aesthetic quality. The surface charge (zeta potential) on C. hirundinella cells can be used to evaluate the best coagulation conditions within an operating window of -10 mV to +3 mV when dosing various coagulants. Scanning electron microscopy investigations revealed major damaging effects to C. hirundinella cells when dosing high Ca(OH)2 concentrations. However, when dosing lower Ca(OH)2 concentrations, in combination with organic polymer, better C. hirundinella cell removal efficiencies with less damaging effects to cells was observed. This study also indicated that the pre-chlorination, without causing cell lyses, can be applied to render the highly motile cells immobile which will subsequently assist the coagulation unit process. The aesthetic quality (e.g. tastes and odours) of drinking water may be influenced when C. hirundinella cells release organic material into the water as a result of cell lyses. Organic compounds, such as fatty acids and dicarboxylic acids can lead to taste and odour problems which associate with the presence of C. hirundinella. Organic compounds also serve as precursors for the formation of harmful chlorine by-products formed during chlorination. / PhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

O objetivo deste trabalho foi aperfeiçoar o filtro lento em escala domiciliar (FLD) à realidade das comunidades isoladas brasileiras com o uso conjunto de pré-tratamento e pós-tratamento acessíveis. As espécies cactáceas Opuntia cochenillifera e Opuntia ficus indica foram avaliadas em ensaios de tratabilidade como coagulantes naturais em pó. A melhor condição para remoção de turbidez e cor aparente foi com 30 mg.L-1 de O. cochenillifera em pH sem a necessidade de correção (± 6,8). O pré-tratamento adaptado às comunidades isoladas utilizando o coagulante natural apresentou valores compatíveis de turbidez (7,83 ± 2,32 uT) para inserção aos filtros. Os FLDs em fluxo contínuo (taxa de filtração de 1,22 m³/m².dia) e em fluxo intermitente (taxa de filtração máxima de 2,79 m³/m².dia) demonstraram redução da turbidez, da cor aparente, dos coliformes totais e da Escherichia coli e produziram água filtrada com ausência de cistos de Giardia spp. e oocistos de Cryptosporidium spp. O FLD em fluxo contínuo teve a maior eficiência em relação à turbidez (± 81,2%); enquanto que o FLD operado em fluxo intermitente apresentou melhores eficiências para a remoção da cor aparente (48,4%), dos coliformes totais (2,60log ± 0,99) e da E. coli (2,86log ± 0,79). Os principais microrganismos atuantes no schmutzdecke dos FLDs foram ciliados (como, por exemplo, a Vorticella sp.), nematódeos e rotíferos. A esponja-vegetal (Luffa cylindrica) e o quiabo (Hibiscus esculentus) foram ponderados como desinfetantes alternativos para o pós-tratamento aos FLDs. As sementes da L. cylindrica e o fruto da H. esculentus foram avaliados através do preparo do extrato e as folhas da L. cylindrica através do preparo em pó. A melhor condição para inativação de E. coli foi com 1 g.L-1 do extrato de H. esculentus em pH sem a necessidade de correção (± 6,8) durante um tempo de contato de 30 min. Essa condição forneceu 1,12log (± 0,16) para a inativação de E. coli, contudo não afetou a viabilidade dos (oo)cistos de Giardia spp. e Cryptosporidium spp. Em ensaios toxicológicos com Chironomus xanthus, a água filtrada não apresentou toxicidade. / The aim of this study was to improve the household-scale slow sand filter (HSSF) to the reality of isolated Brazilian communities with combined use of pre-treatment and post-treatment approachable. Cacti species Opuntia cochenillifera e Opuntia ficus indica were evaluated in Jar tests as powder natural coagulants. The best condition for turbidity and apparent color removal was with 30 mg.L-1 of O. cochenillifera at pH without correction (± 6,8). Pre-treatment adapted to isolated communities using natural coagulant showed compatible turbidity values (7.83 ± 2.32 uT) for insertion into the filters. The HSSFs with continuous (filtration rate of 1,22 m³/m².day) and intermittent operation (maximum filtration rate of 2,79 m³/m².day) demonstrated reductions in turbidity, apparent color, total coliforms and Escherichia coli and produced filtered water without Giardia spp. cysts and Cryptosporidium spp. oocysts. The HSSF in continuous operation had the highest turbidity efficiency (± 81.2%); while the HSSF in intermittent operation had showed better efficiencies for the apparent color (48,4%), total coliforms (2,60log ± 0,99) and E. coli (2,86log ± 0,79). The main microorganisms active in the schmutzdecke were ciliates (for example, Vorticella spp.) nematodes and rotifers. Luffa cylindrica and Hibiscus esculentus were evaluated as alternative disinfectant for post-treatment to HSSF. L. cylindrica seed and H. esculentus fruit were tested as extract and L. cylindrica leave was tested powder. The best condition for E. coli inactivation was with 1 g.L-1 of H. esculentus extract at pH without correction (± 6,8) during 30 min. This condition provided 1,12log (± 0,16) for E. coli inactivation, however did not affect Giardia spp. cysts and Cryptosporidium spp. oocysts viability. In toxicological tests with Chironomus xanthus, the filtered water showed no toxicity.

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2017-12-01T22:57:34Z No. of bitstreams: 1 Juliana_Dotto_2013.pdf: 2822116 bytes, checksum: 3b8be919381051b7c1e0d2252f604aed (MD5) / Made available in DSpace on 2017-12-01T22:57:34Z (GMT). No. of bitstreams: 1 Juliana_Dotto_2013.pdf: 2822116 bytes, checksum: 3b8be919381051b7c1e0d2252f604aed (MD5) Previous issue date: 2013-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study evaluated the efficiency of organic coagulants like seeds of Moringa oleifera Lam extracted in saline solutions of sodium chloride and potassium chloride1,0 (MO-NaCl and MO-KCl, respectively) and inorganic coagulants like aluminum sulfate and ferric chloride to the treatment of textile wastewater. Initially, it has been evaluated the best pH for each coagulant studied to then optimize the concentration of the coagulants and settling time. For this finality, it has been used velocity of rapid mixing (VMR) and slow (VML) at 100 rpm and 20 rpm, respectively and time of rapid mixing (TMR) and slow (TML) for 2 minutes and 20minutes, respectively. The parameters analyzed were pH after treatment, absorbance at a wavelength of maximum absorption for each dye present in the wastewater (Procion Orange HER and Procion Red HE-7B), color, turbidity and COD. In the test for optimization of coagulants concentration and settling time, also was evaluated the amount of sludge generated at each concentration studied. Thus, organic coagulants showed superior results in comparison with inorganic coagulants in the treatment of textile wastewater, especially MO-KCl, which showed removal of 86,8% for absorbance of the dye Procion Orange HER, 75,65% for absorbance of the dye Procion Red HE-7B, 70,67%forcolor, 85,97% for COD and 64,07% for turbidity. Based on the results obtained, MO-KCl presented a promising coagulant in the treatment of textile wastewater. / O presente estudo avaliou a eficiência dos coagulantes orgânicos sementes de Moringa oleifera lam extraídas em soluções salinas de cloreto de sódio e cloreto de potássio 1,0 (MO-NaCl e MO-KCl) respectivamente, além dos inorgânicos sulfato de alumínio e cloreto férrico no tratamento de água residuária têxtil. Inicialmente, avaliou-se o melhor pH de trabalho para cada coagulante estudado, para, em seguida, otimizar a concentração do coagulante e o tempo de sedimentação. Para isto, utilizou-se velocidade de mistura rápida (VMR) e lenta (VML) de 100 rpm e 20 rpm respectivamente, e tempo de mistura rápida (TMR) e lenta (TML) de 2 minutos e 20 minutos, respectivamente. Os parâmetros analisados foram pH após tratamento, absorbância no comprimento de onda máximo de cada corante presente na água residuária (Laranja Procion HER e Vermelho Procion HE-7B), cor, turbidez e DQO. Além destes, no teste para otimização da concentração de coagulante e tempo de sedimentação, avaliou-se a quantidade de lodo gerado em cada concentração estudada. Assim, os coagulantes orgânicos apresentaram resultado superior aos inorgânicos no tratamento da água residuária têxtil, com destaque para a MO-KCl, que apresentou remoção de 86,8% para absorbância do corante Laranja Procion HER, 75,65% para absorbância do corante Vermelho Procion HE-7B, 70,67% para cor aparente, 85,97% para DQO e 64,07% para turbidez. Com base nos resultados obtidos a MO-KCl pode ser considerada um coagulante promissor para o tratamento da água residuária têxtil.

O objetivo deste trabalho foi aperfeiçoar o filtro lento em escala domiciliar (FLD) à realidade das comunidades isoladas brasileiras com o uso conjunto de pré-tratamento e pós-tratamento acessíveis. As espécies cactáceas Opuntia cochenillifera e Opuntia ficus indica foram avaliadas em ensaios de tratabilidade como coagulantes naturais em pó. A melhor condição para remoção de turbidez e cor aparente foi com 30 mg.L-1 de O. cochenillifera em pH sem a necessidade de correção (± 6,8). O pré-tratamento adaptado às comunidades isoladas utilizando o coagulante natural apresentou valores compatíveis de turbidez (7,83 ± 2,32 uT) para inserção aos filtros. Os FLDs em fluxo contínuo (taxa de filtração de 1,22 m³/m².dia) e em fluxo intermitente (taxa de filtração máxima de 2,79 m³/m².dia) demonstraram redução da turbidez, da cor aparente, dos coliformes totais e da Escherichia coli e produziram água filtrada com ausência de cistos de Giardia spp. e oocistos de Cryptosporidium spp. O FLD em fluxo contínuo teve a maior eficiência em relação à turbidez (± 81,2%); enquanto que o FLD operado em fluxo intermitente apresentou melhores eficiências para a remoção da cor aparente (48,4%), dos coliformes totais (2,60log ± 0,99) e da E. coli (2,86log ± 0,79). Os principais microrganismos atuantes no schmutzdecke dos FLDs foram ciliados (como, por exemplo, a Vorticella sp.), nematódeos e rotíferos. A esponja-vegetal (Luffa cylindrica) e o quiabo (Hibiscus esculentus) foram ponderados como desinfetantes alternativos para o pós-tratamento aos FLDs. As sementes da L. cylindrica e o fruto da H. esculentus foram avaliados através do preparo do extrato e as folhas da L. cylindrica através do preparo em pó. A melhor condição para inativação de E. coli foi com 1 g.L-1 do extrato de H. esculentus em pH sem a necessidade de correção (± 6,8) durante um tempo de contato de 30 min. Essa condição forneceu 1,12log (± 0,16) para a inativação de E. coli, contudo não afetou a viabilidade dos (oo)cistos de Giardia spp. e Cryptosporidium spp. Em ensaios toxicológicos com Chironomus xanthus, a água filtrada não apresentou toxicidade. / The aim of this study was to improve the household-scale slow sand filter (HSSF) to the reality of isolated Brazilian communities with combined use of pre-treatment and post-treatment approachable. Cacti species Opuntia cochenillifera e Opuntia ficus indica were evaluated in Jar tests as powder natural coagulants. The best condition for turbidity and apparent color removal was with 30 mg.L-1 of O. cochenillifera at pH without correction (± 6,8). Pre-treatment adapted to isolated communities using natural coagulant showed compatible turbidity values (7.83 ± 2.32 uT) for insertion into the filters. The HSSFs with continuous (filtration rate of 1,22 m³/m².day) and intermittent operation (maximum filtration rate of 2,79 m³/m².day) demonstrated reductions in turbidity, apparent color, total coliforms and Escherichia coli and produced filtered water without Giardia spp. cysts and Cryptosporidium spp. oocysts. The HSSF in continuous operation had the highest turbidity efficiency (± 81.2%); while the HSSF in intermittent operation had showed better efficiencies for the apparent color (48,4%), total coliforms (2,60log ± 0,99) and E. coli (2,86log ± 0,79). The main microorganisms active in the schmutzdecke were ciliates (for example, Vorticella spp.) nematodes and rotifers. Luffa cylindrica and Hibiscus esculentus were evaluated as alternative disinfectant for post-treatment to HSSF. L. cylindrica seed and H. esculentus fruit were tested as extract and L. cylindrica leave was tested powder. The best condition for E. coli inactivation was with 1 g.L-1 of H. esculentus extract at pH without correction (± 6,8) during 30 min. This condition provided 1,12log (± 0,16) for E. coli inactivation, however did not affect Giardia spp. cysts and Cryptosporidium spp. oocysts viability. In toxicological tests with Chironomus xanthus, the filtered water showed no toxicity.

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.