Tesi sul tema "Flocculation Tests"

As populations continue to grow, the demand for fresh drinking water is increasing. This puts a lot of pressure on drinking water producers to strive for more efficient solutions and techniques. Many producers worldwide use surface water as a raw water source, which they often treat through coagulation and flocculation techniques. This is done by adding coagulant (e.g. metal coagulants), creating instability in the suspension, causing flocculation. In this work, PIX-311 (a FeCl3 coagulant produced by Kemira) and Al2(SO4)3 (Kemwater ALG) were used as primary coagulants and CaCl2 (produced by TETRA Chemicals) as an adjunct in a coagulation and flocculation study. The goal of this work was to study the effects of CaCl2 additions to Fe(III) and Al(III) flocculation. The experiments were conducted at Ringsjöverket (a water treatment facility), using jar tests to simulate the treatment process on a laboratory scale. The raw water samples used in this study, were taken from Bolmen, a lake in southern Sweden. A spectrophotometer was used to monitor the efficiency of flocculation by UV-VIS absorption. In the first experiments, various CaCl2 additions were added to Fe(III) flocculation, with FeCl3 as a primary coagulant. To see if FeCl3 could be substituted with CaCl2, the amount of primary coagulant was reduced to about 80% of the optimal dosage (the dose used daily by the water treatment plant). In the next series of experiments, various amounts of CaCl2 were added with an optimal dose of FeCl3. After that, the effects of CaCl2 additions to Al(III) flocculation were conducted, using Al2(SO4)3 as a primary coagulant. The experiments followed the previous scheme used in Fe(III) flocculation. The UV-VIS results showed that no CaCl2 additions were effective enough to replace the primary coagulant. However, reduced amount of primary coagulant benefited slightly from small CaCl2 additions. A likely explanation for this is the ability of Ca2+ to aid in charge neutralization and reduce the repulsive forces between particles in suspension, aiding coagulation. Furthermore, CaCl2 additions, with reasonable certainty, did not increase the efficiency of Fe(III) flocculation. When the CaCl2 dose was increased (from about 13µl to 820 µl per liter raw water), the effect became negative. In other words, high doses of CaCl2 inhibited flocculation by, most likely, occupying adsorption sites for the primary coagulant. This was observed for an optimal FeCl3 dose, reduced FeCl3 dose and an optimal dose of Al2(SO4)3. In the more brief study on Al(III) flocculation, low CaCl2 doses did not appear to have any effect on flocculation at first.  However, when a reduced amount of Al2(SO4)3 was used, the samples with CaCl2 gave better UV-VIS results once the pH was increased from 6 to about 6.15. One explanation for this could be that the shift in flocculation mechanism at higher pH, causes CaCl2 to have an increased positive effect.

Jar testing is one of the most common tools that water treatment facilities use to determine the treatment conditions necessary to meet finished water quality goals. A six-place stirrer is normally used for jar testing to provide identical mixing conditions while coagulant dose and pH vary in each jar to create “floc” that is removed via sedimentation. There are some utilities that are unable to utilize jar testing, since the current jar testing procedures do not identify optimum treatment conditions for their water supply. This is particularly true for those utilities treating low-turbidity, low-TOC waters because low coagulant doses can produce small floc that does not settle efficiently (even though it is removed efficiently by filters). A modified jar test procedure was developed with the goal of providing consistent and reliable results for all treatment facilities without having to make site-specific changes to the mixing speeds and times to try to match the plant performance. Instead of sedimentation, the modified jar test procedure uses a novel granular media filter along with a standardized mixing protocol and titrations to predict and control the pH of the coagulated water. Contour mapping of jar test data was utilized to provide a detailed visual description of zones of effective treatment. Research found that the application of direct filtration (instead of traditional sedimentation) reduced testing time and showed better correlation to treatment plant performance. A method of optimizing coagulant dose and coagulated pH based on titrations is proposed, which is based on an alternating, single-variable optimization method with experimentally determined starting points. Treatment with coagulant only (i.e., without prior pH adjustment) limits the range of coagulation conditions a water treatment plant can operate at. Coagulants are acidic and their addition during treatment causes both the pH and coagulant dose to change simultaneously. Treating water with coagulant only provides only one diagonal path for treatment to occur across a two-dimensional area of pH and coagulant dose combinations, which sometimes misses optimal treatment conditions entirely.

Dentre as características desejáveis em leveduras fermentadoras alcóolicas estão a capacidade de floculação, a não produção de H2S e o caráter "killer". Neste trabalho foram selecionadas sete linhagens de Saccharomyces cerevisiae com algumas destas características, que passaram por testes confirmativos e pela cariotipagem eletroforética resultando na escolha de duas linhagens: ATCC 26602 (altamente floculante) e K1 (H2S - e possuidoras do caráter "killer"). Estas linhagens foram utilizadas em um cruzamento via fusão de protoplasto para se obter um produto de fusão estável com as características de interesse tecnológico. Na seleção das linhagens híbridas com base em caracteres naturais foram isolados 1291 híbridos em meio seletivo e entre essas colônias somente 1,5% foram inicialmente consideradas híbriadas. Após três subcultivos em YEPD líquido, estes produtos de fusão não se mostraram estáveis.
Flocculative and "killer" skills and lack in production of H2S are desirable characteristics of the ethanolic fermentative yeasts. Seven selected strains of Saccharomyces cerevisiae with some of these characteristics were evaluated for confirmation of these habilities and their genetic characterization was undertaken by eletrophoretic kariotyping. The strain ATCC 26602 had flocculant hability and the strain K1 was H2S - and "killer". The strains were selected for protoplast fusion aiming to obtain a stable fusion strain with these desirable technologyc characteristics. The selection of the hybrid strains were based on natural characters and have shown 1291 hybrids (frequency of 1,5%) in the medium for the isolation of the fusionants (protoplasts). The protoplast stability were monitored by three continuous growth in the YEPD liquid midium and the stable fusion products were not obtained.

A floculação é o principal estágio do tratamento da água e apesar dos significativos avanços alcançados nos últimos anos, a compreensão do mecanismo de floculação está longe de ser completa. O objetivo principal do presente trabalho foi investigar a cinética de floculação de suspensões coloidais, através da influência da dosagem de coagulante metálico e da concentração de partículas primárias nas constantes de agregação e ruptura, utilizando o modelo de Argaman e Kaufman para a cinética de floculação de um reator em batelada. A água bruta sintética foi feita com a adição de caolinita, de tal forma a obter os valores de turbidez prédeterminados de 15 UNT, 50 UNT e 100 UNT, representando águas de baixa, média e alta turbidez, respectivamente, e o coagulante utilizado foi o sulfato de alumínio. Os resultados experimentais foram obtidos em ensaios de \"jar test\" utilizando 6 dosagens de coagulantes, 6 gradientes de velocidade, 3 velocidades de sedimentação e 12 tempos de floculação para cada uma das três águas analisadas. Pode-se observar que, para água de baixa e média turbidez, com o aumento da dosagem de coagulante houve um gradativo aumento da constante de agregação, no entanto, para água de alta turbidez, para valores de dosagem de coagulante acima de 40mg.L-1, passa a ocorrer uma redução na constante de agregação, e também houve um aumento da constante de ruptura para as três águas brutas utilizadas na investigação experimental. Para todas as dosagens de coagulante empregadas, com o aumento da turbidez da água bruta, houve uma diminuição significativa da constante de ruptura ocorrida na água bruta de baixa turbidez para a água bruta de média turbidez. Embora também tenha sido observada uma variação na constante de agregação, esta foi muito pequena quando comparada numericamente com as variações na constante de ruptura. Com o aumento da turbidez da água bruta de 50 UNT para 100 UNT, a variação da constante de ruptura ocorreu apenas de forma marginal, o que significa dizer que, embora esta seja função da turbidez da água bruta, a sua relação não deve ser simplesmente linear, conforme sugerido por Argaman e Kaufman.
Flocculation is the main stage of water treatment and in spite of significant advances in recent years, understanding of the flocculation mechanism is far from complete. The main objective of current work was to investigate the kinetics of flocculation of colloidal suspensions, throughout the influence in metallic coagulant dosage and the concentration of primary particles in aggregation and rupture constants, using the Argaman and Kaufman model for kinetics of flocculation in a batch reactor. Synthetic raw water was made with the addition of kaolin, in order to obtain predetermined turbidity values of 15 NTU, 50 NTU and 100 NTU, representing waters of low, medium and high turbidity, respectively, and the coagulant applied was aluminum sulfate. Experimental results were obtained in \"jar test\" experiments using 6 coagulant dosages, 6 velocity gradients, 3 sedimentation velocity and 12 flocculation times for each water analyzed. It can be observed that, for waters of low and medium turbidity, with the coagulant dosage increase, takes place a gradual increase in aggregation constant, however, on waters of high turbidity, with coagulant dosages above 40mg.L-1, A reduction in aggregation constant occurs, and also there was seen an increase in rupture constant for the three raw waters used in the experimental investigation. For all employed coagulant dosages, with the increase in raw water turbidity, there were a significant decrease in rupture constant occurred in raw water of low turbidity to medium turbidity raw water. Although a variation in the aggregation constant was also observed, this was very small when numerically compared with the variation in rupture constant. With the increase in raw water turbidity from 50 NTU to 100 NTU, rupture constant variation occurred only in a marginal manner, meaning to say, while this is in function of raw water turbidity, its relation might not be simply linear, as suggested by Argaman and Kaufman.

Durante a floculação, a agitação promove dois efeitos simultaneamente, a agregação e a ruptura. A ruptura ocorre devido à atuação de forças de cisalhamento sobre os flocos. O aumento da agitação com, conseqüentemente, aumento do gradiente de velocidade médio, em água com flocos formados, promove o aumento das forças de cisalhamento e a degradação parcial ou total dos mesmos, em poucos segundos. Retornando à condição anterior de agitação, pode ocorrer o recrescimento dos flocos. Através de ensaios em reatores estáticos (em equipamento de jarteste) foram estudados os efeitos da ruptura e da refloculação na sedimentação dos flocos, para velocidades de sedimentação entre 0,9 e 7,0 cm/min. A água de estudo foi preparada com caulinita, resultando turbidez de 100 uT, e coagulada com sulfato de alumínio. Foram realizadas as etapas de coagulação, mistura rápida, floculação, ruptura (G=75, 150 e 250 \'S POT.-1\') e refloculação (G=25, 20 e 15 \'S POT.-1\'). A ruptura, em poucos segundos, prejudicou a remoção dos flocos por sedimentação. Quanto maior o gradiente de velocidade na ruptura, maiores foram os valores da turbidez remanescente do sobrenadante, mesmo após a refloculação. A refloculação, mesmo nos primeiros minutos, diminuiu a turbidez remanescente do sobrenadante se comparada a logo após a ruptura. Quanto menor o gradiente de velocidade durante a refloculação, menores foram os valores da turbidez remanescente do sobrenadante. Apenas para velocidades de sedimentação, gradientes de velocidade de ruptura e gradientes de velocidade de refloculação menores ou iguais a 2,5 cm/min, 75 \'S POT.-1\' e 15 \'S POT.-1\', respectivamente, foi possível obter sobrenadante com valores de turbidez remanescente similares aos encontrados inicialmente, sem ruptura.
During the flocculation, the shear rate promotes two effects simultaneously, growth and breakage of flocs. The break up of flocs is caused as a result of disruptive forces. The increase of the shear rate in water with formed flocs increases the disruptive forces and it also can break the flocs partial or totally in a few seconds. Restoring the previous low shear conditions, flocs can grow back. By using the jar test equipment, the effects of breakage and reflocullation on the efficiency of floc sedimentation were studied, using settling velocities between 0.9 e 7.0 cm/min. Water of study was prepared with groundwater and kaolin, resulting a turbidity of approximately 100 NTU. Coagulation was performed by using aluminum sulfate. Coagulation, flocculation, breakage (G=75, 150 e 250 \'S POT.-1\') and reflocculation tests were carried out. In a few seconds the breakage of flocs hindered the settling removal of turbidity. The higher the average shear rate in the break-up, the higher result the residual turbidity even after the reflocculation. In the first minutes, the reflocculation decreased the residual turbidity after sedimentation if compared to the residual turbidity just after the break-up and sedimentation. The lower the average shear rate during the reflocculation, the lower result the supernatant values of residual turbidity. Supernatant could only be obtained with the value of residual turbidity similar to the values found initially (without breakage of flocs) for the settling velocity, the average velocity gradient of break-up and the average velocity gradient of reflocculation equal or less than 2.5 cm/min, 75 \'S POT.-1\' e 15 \'S POT.-1\', respectively.

Este presente trabalho teve como objetivo a investigação do desempenho de um biopolímero experimental à base de cálcio, desenvolvido e fornecido por uma empresa americana, na coagulação, floculação e sedimentação da vinhaça bruta como tratamento físico-químico na remoção de carga orgânica e na concentração de compostos fertilizantes no lodo. O estudo do tratamento da vinhaça por meio da aplicação deste biopolímero possibilitaria, hipoteticamente, uma redução significativa da carga orgânica como tratamento inicial da vinhaça, além de concentrar os nutrientes presentes na vinhaça no lodo gerado para uso fertilizante. Foram realizados ensaios com coagulantes convencionais (sulfato ferroso, cloreto férrico e óxido de cálcio) para efeito de comparação entre estes e o biopolímero. Os ensaios de coagulação, floculação e sedimentação foram realizados em escala de laboratório com uso do equipamento Jar Test. Os ensaios foram divididos em três etapas. Na primeira etapa foram realizados ensaios aplicando-se determinadas dosagens de biopolímero e variando-se os tempos de coagulação, velocidades de rotação, além de realizar ou não a mistura lenta após a etapa de coagulação, a fim de verificar se estes parâmetros poderiam otimizar o processo de tratamento com o aplicação do biopolímero. Para segunda etapa do procedimento experimental foram realizados ensaios com os outros coagulantes: óxido de cálcio, sulfato férrico e cloreto férrico. Os ensaios com o cloreto férrico e o sulfato férrico foram realizados nas seguintes condições: velocidade de mistura rápida de 200 rpm por um período de tempo de 30 segundos e velocidade de mistura lenta de 80 rpm por um período de 20 minutos. Já os ensaios com óxido de cálcio foram realizados com apenas velocidade de mistura rápida de 200 rpm variando os períodos de tempo em 1, 5 e 10 minutos. O tempo de sedimentação para separação dos flocos formados foi de 2 horas para todas as etapas. O tratamento com biopolímero experimental apresentou resultados de remoção de matéria orgânica abaixo dos valores esperados, que era na faixa de 60% a 80%. Os resultados limitaram-se a valores de 10% a 35% de remoção de DQO. Porém, a remoção de turbidez atingiu valores elevados, próximos a 90%. Para os compostos relacionados à fertilização NPK (nitrogênio, fósforo e potássio), o tratamento com biopolímero experimental obteve as melhores eficiências de remoção de fósforo (48,3%) e de NTK (17,2%) em relação aos demais coagulantes, porém não apresentou remoção de potássio. Não houve diferença significativa na eficiência de remoção de DQO quando se alteram as condições operacionais de velocidade de agitação. Já o aumento no tempo de agitação diminui a eficiência de remoção de DQO.
This work aimed to investigate the performance of an experimental biopolymer calcium-based, developed and supplied by an American company, on gross vinasse coagulation, flocculation and sedimentation as a physical chemical treatment on organic load removal and on fertilizer compounds concentration in sludge. The study of the vinasse treatment through the application of this biopolymer would allow, hypothetically a significant reduction of the organic load as vinasse initial treatment, besides concentrating the vinasse found nutrients in the sludge created for fertilizer use. Assays were performed with conventional coagulants (ferrous sulfate, ferric chloride and calcium oxide) for comparison between them and the biopolymer. Tests of coagulation, flocculation and sedimentation were carried out in laboratory scale using Jar Test equipment. The experiments were divided in three stages. In the first stage assays were performed applying certain dosages of biopolymer and varying the clotting time, rotational speeds in addition to performing or not performing the slow mixture after the clotting stage in order to check if these parameters could optimize the treatment process with the biopolymer application. For the second stage of the experimental procedure tests were developed with other coagulants: calcium oxide, ferric sulphate and ferric chloride. Tests with ferric chloride and ferric sulphate were performed under the following conditions: fast mixing speed of 200 rpm for a period of 30 seconds and slow mixing speed of 80 rpm for a period of 20 minutes. Considering the assays with calcium oxide, they were carried out using only rapid mixing speed of 200 rpm by varying the time periods at 1, 5 and 10 minutes. The sedimentation time to the formed flakes separation was two hours for all stages. Treatment with experimental biopolymer presented results of removal of organic matter below the expected values, which was in the range 60% to80%. The results limited to values of 10% to 35% of COD clearance. However, the removal of turbidity reached high values near 90%. For compounds related to NPK (nitrogen, phosphorus and potassium) fertilization, the treatment with experimental biopolymer obtained the best efficiency of phosphorus removal (48,3) and TKN removal (17.2%) in comparison with the other coagulants, but showed no removal of potassium. There was no significant difference in COD removal efficiency when the operating conditions of agitation speed are changed. Regarding to the increase in the agitation time, it reduces the efficiency of COD removal.

As melhoras nas condições de disposição de resíduos sólidos em aterros sanitários teve, como conseqüência, a geração de um efluente com um grande potencial poluidor, o lixiviado de aterro sanitário, que anteriormente percolava pelo solo. Com o confinamento da massa de lixo e a impermeabilização do aterro, o lixiviado começou a ser coletado exigindo que o mesmo fosse tratado. A necessidade do tratamento deste efluente está relacionada com sua toxidade,pois contém altas concentrações de amônia, metais e alta carga orgânica que se originam da decomposição de compostos contidos no interior do aterro sanitário. Nesta pesquisa olixiviado é submetido a um pré-tratamento biológico com remoção de nitrogênio, no qual a maior parte da matéria orgânica, principalmente a facilmente biodegradável, é consumida,sobrando apenas compostos de cadeias longas de difícil biodegradabilidade e compostos inorgânicos, que são denominados compostos recalcitrantes, sendo em grande parte formados por substâncias húmicas. A intenção do trabalho foi maximizar a remoção destes compostos por meio de um tratamento físico-químico, realizado pelo processo de coagulação-floculação e é considerado uma forma complementar ao tratamento biológico. A pesquisa foi dividida em diversas etapas, em escala de bancada utilizando o jar teste, variando condições de pH de 2,0 a 5,0 e 10 a 12,0, com dosagens de coagulantes de 400mg Fe+³/l e polímeros aniônicos de alto peso molecular com dosagens de 0,5mg/l a 10,0 mg/l, a fim de encontrar a melhor condição de remoção dos compostos recalcitrantes, com o intuito de melhorar ao máximo as condições do efluente a fim de causar o menor impacto possível do mesmo ao ser lançado em cursos de água. De acordo com as variações na condição de tratamento do lixiviado, definiu-se que, com a diminuição do pH a 4,0 seguido de dosagens de 400mg Fe+³/l e ainda com a adição de 2,0 mg/l de polímero, foi possível atingir condições de remoção da ordem de 98% de cor e 80% de COT, indicando que a utilização de polímero é eficiente no processo de tratamento físico químico pelo processo de coagulação floculação de lixiviado de aterro sanitário
The improvements in the conditions of solid waste disposal in landfills has, as a consequence, the generation of an effluent polluted with great potential, landfill leachate, which previously percolated through the soil. With the containment of the waste stream and sealing of the landfill, the leachate began to be collected by requiring that it be treated. The need for treatment of wastewater is related to its toxicity, because it contains high concentrations of ammonia, metals and high organic load originating from the decomposition of compounds contained within the landfill. In this research the leachate is subjected to a pre- biological treatment with nitrogen removal, in which most of the organic matter, especially the readily biodegradable, is consumed, leaving only long-chain compounds difficult biodegradability and inorganic compounds, which are called recalcitrant compounds, being largely composed of humic substances. The intention of this study was to maximize the removal of these compounds by means of a physical-chemical treatment, performed by coagulation-flocculation process and is considered a complement to a biological treatment. The research was divided into several stages, using bench scale jar test conditions of pH ranging from 2.0 to 5.0 and 10 to 12.0, with dosages of coagulants Fe+³ 400 mg/l anionic polymers high molecular weight with dosages of 0.5 mg/l to 10.0 mg/l, in order to find the best condition for removal of recalcitrant compounds, with the most to improve the conditions of the effluent in order to cause minimum possible impact thereof to be released into waterways. According to the variations in the treatment condition of the leachate, it was decided that, with decreasing pH to 4.0 followed by doses of 400 mg Fe+³/l, even with the addition of 2.0 mg/l polymer conditions it was possible to achieve removal of about 98% color and 80% TOC, indicating that the use of polymer is effective in the physical-chemical treatment process by coagulation flocculation process for landfill leachate.

O objetivo principal desta pesquisa foi comparar o desempenho de dois reatores anaeróbios híbridos de biomassa imobilizada (RAHBI), em escala de laboratório, no processamento da vinhaça de cana-de-açúcar. Um (reator 1) recebendo vinhaça sem tratamento prévio e outro (reator 2) processando vinhaça previamente submetida à coagulação, utilizando-se de um biopolímero experimental a base de cálcio. Os reatores foram construídos em acrílico, com volume de 1,5 litros cada, provido de sistema de recirculação com razão igual a 3. A operação dos reatores foi dividida em duas etapas: a primeira, com duração de 69 dias, teve seu fim caracterizado por um colapso apresentado pelo reator 2. A segunda fase, com duração de 37 dias, onde se observou outro colapso. O principal parâmetro de controle no monitoramento dos reatores foi a quantificação de matéria orgânica, em termos de Demanda Química de Oxigênio (DQO). Durante a Fase I, o reator 1 apresentou eficiência de remoção média de 82,9 ± 4,4% , e o reator 2 de 72,2 ± 18,1%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,3 ± 1,3 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,3 ± 1,6 kg DQO/\'M POT.3\'d. O colapso ocorrido no reator 2 foi evidenciada pelo decréscimo acentuado da eficiência de remoção, chegando a 33,7%. Durante a Fase II, o reator 1 apresentou eficiência de remoção média de 77,5 ± 9,4% , e o reator 2 de 79,2 ± 9,7%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,1 ± 2,4 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,0 ± 2,3 kg DQO/\'M POT.3\'. Ao final desta fase o reator 1 apresentou eficiência de remoção de 80,9%, e o reator 2 65.8%. Foram analisados, também, alcalinidade e produção de metano (\'CH IND.4\'). Durante todas as fases, a alcalinidade dos dois reatores esteve acima de 1000 mg \'CA\'CO IND.3\'/l, indicando estabilidade, em relação a este parâmetro, dos reatores. A produção de \'CH IND.4\' do reator 1 foi de 0,0507 ± 0,0232 l \'CH IND.4\'/h e 0,0838 ± 0,0326 l \'CH IND.4\'/h nas fases I e II, respectivamente. Para o reator 2, esta produção foi de 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h, para as fases I e II, respectivamente. Foram feitos ensaios de resistência mecânica dos grânulos, análise de microscopia eletrônica de varredura (MEV), Espectrometria de Energia Dispersiva de Raios-X (EDS) e análise da comunidade microbiana, empregando técnicas de biologia molecular. Os testes de resistência mecânica dos grânulos indicam que os grânulos contidos no inóculo, reatores 1 e 2 possuem resistência à desintegração. As análises de MEV e EDS indicam a presença do elemento cálcio com aproximadamente 22% para o inóculo, 39% para o reator 1 e 50% para o reator 2, na massa dos elementos analisados das amostras de grânulos. As análises de biologia molecular indicaram similaridades entre os reatores 1 e 2 de 66,5 e 58%, para os domínios Bacteria e Archea, respectivamente. Desta forma, supõe-se que esta diferença da biota entre os reatores não estaria contribuindo para a falha conferida no reator 2.
This research aimed at compare the performance of two hybrid anaerobic immobilized biomass (HAIB), in laboratory scale, processing vinasse from sugar cane alcohol destilery. Reactor 1 received vinasse without pre-treatment. Reactor 2 processed coagulated vinasse using a calcium-based biopolymer as coagulant. The two reactors were built in acrylic, with a volume of 1,5 liters each. The recirculation flow rate was 3. The operation of the reactors was divided in two phases: first, lasting 69 days, came to an end characterized by a failure (collapse) presented by the reactor 2. The second phase, lasting 37 days, came to an end characterized by another collapse. The main control parameter in the monitoring of the reactors was the quantification of organic matter in terms of COD. During Phase I, the reactor 1 showed average removal efficiency of 82,9 ± 4,4%, and the reactor 2 72,2 ± 18,1%. The organic loading rate (VOC) average applied to reactor 1, during this phase, was 5,3 ± 1,3 kg DQO/\'M POT.3\'d, and 5,3 ± 1,6 kg DQO/\'M POT.3\'d for the reactor 2. The failure occurred in the reactor 2 was evidenced by the sharp decrease of removal efficiency, reaching 33.7%. During Phase II, the reactor 1 showed average removal efficiency of 77,5 ± 9,4%, and the reactor 2 79,2 ± 9,7%. The average VOC applied to reactor 1, during this phase, was 5,1 ± 2,4 kg DQO/\'M POT.3\'d, and 5,0 ± 2,3 kg DQO/\'M POT.3\'d for reactor 2. At the end of this phase, the reactor 1 showed a removal efficiency of 80.9%, and the reactor 2 65.8%. Has also been analyzed, alkalinity and methane (\'CH IND.4\'). During all the phases, the alkalinity of both reactors was above 1000 mg \'CA\'CO IND.3\'/l, indicating stability in the reactors. The production of \'CH IND.4\' was 0.0507 ± 0.0232 l \'CH IND.4\'/h and 0.0326 ± 0.0838 l \'CH IND.4\'/h in phases I and II, respectively. For the reactor 2, the production of \'CH IND.4\' was 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h for the phases I and II, respectively. Assays were performed in mechanical granules strength, analysis of scanning electron microscopy (SEM), Energy Dispersive Spectroscopy X-ray (EDS) and analysis of the microbial community, using molecular biology techniques. The tests of mechanical of granules strength indicate that the granules contained in the inoculum, reactors 1 and 2 are resistant to disintegration. The SEM and EDS analysis indicated the presence of calcium element with approximately 22% inoculum, 39% for reactor 1 and 50% for reactor 2, in the mass of the elements analyzed samples of granules. The microbial community analyzes indicated molecular similarity between the first and second reactor of 66.5 and 58% for Bacteria and Archea domain, respectively. Thus, it is assumed that the difference between the biota of the reactors would not be contributing to the failure given in the reactor 2.

Por meio de ensaios em reatores estáticos (em equipamento de jarteste) foram estudados os efeitos da ruptura e da refloculação na sedimentação dos flocos, para diferentes velocidades de sedimentação. A água de estudo foi preparada com substâncias húmicas aquáticas (SHA) extraídas de água coletada do rio Itapanhaú - Bertioga/SP, resultando cor verdadeira de 100 uH, e coagulada com sulfato de alumínio e cloreto férrico. Para os dois coagulantes, foram realizadas as etapas de coagulação, mistura rápida, floculação, ruptura (G=50, 100 e 150/s) e refloculação (G=10 e 20/s). Na sedimentação sem a ocorrência de ruptura o cloreto férrico teve um desempenho superior ao sulfato de alumínio, principalmente nas velocidades de sedimentação mais altas. Isso se deve ao fato da floculação da água coagulada com o cloreto férrico ter gerado flocos de tamanho muito superior aos flocos gerados com o sulfato de alumínio. A ruptura, em poucos segundos, prejudicou a remoção dos flocos por sedimentação. Quanto maior o gradiente de velocidade na ruptura, maiores foram os valores da cor aparente remanescente, mesmo após a refloculação. A refloculação, mesmo nos primeiros minutos, diminuiu a cor aparente remanescente se comparada a logo após a ruptura. O menor gradiente de velocidade durante a refloculação testado (10/s) apresentou menores valores da cor aparente remanescente. Tanto na água coagulada com o sulfato de alumínio quanto na coagulada com o cloreto férrico a refloculação se comportou de modo semelhante, havendo recuperação na eficiência de remoção de cor sem, porém, atingir os resultados obtidos antes da ruptura.
By using the jar test equipment, the effects of breakage and reflocullation on the efficiency of floc sedimentation were studied, using different settling velocities. Water of study was prepared with aquatic humic substances (AHS) extracted from the Itapanhaú river (Bertioga, SP, Brazil), resulting a true color of 100 uH. Coagulation was performed by using aluminum sulfate and ferric chloride. For both coagulants, coagulation, flocculation, breakage (G=50, 100 and 150/s) and reflocculation (G=10 and 20/s) tests were carried out. In the sedimentation without the floc breakage occurrence the ferric chloride had a superior performance to aluminum sulphate, mainly in higher settling velocities. This occurred because of flocculation of the ferric chloride coagulated water have generated higher size flocs than that generated with aluminum sulphate. The breakage of flocs, in few seconds, hindered the settling removal. The higher the average shear rate in the break-up, the higher result the residual turbidity even after the reflocculation. The reflocculation, even in the first minutes, decreased the apparent color if compared to the results just after the break-up and sedimentation. The lower average share rate used during the reflocculation (10/s) resulted lower values of the remaining apparent color. During the flocculation, the aluminum sulphate coagulated water as well as in the ferric chloride coagulated water held in similar way, recovering the efficiency of removal of color without, however, reach the results gotten before the breakage.

Lixiviados de aterros sanitários apresentam altas concentrações de nitrogênio amoniacal e matéria orgânica, além de outros poluentes, que não permitem seu descarte no meio ambiente, sem um prévio tratamento. Lixiviados de aterros sanitários mais antigos, com matéria orgânica mais estabilizada, apresentam grande potencial poluidor, principalmente devido à presença de substâncias recalcitrantes que, usualmente, não são removidas através de tratamento biológico, necessitando, portanto, da aplicação de um pós-tratamento. A presente pesquisa objetivou aplicar o tratamento físico-químico a dois efluentes de sistemas biológicos de tratamento. O primeiro sistema era constituído de um reator de lodo ativado operado em bateladas seqüenciais (70 Litros) cujo efluente era submetido à processo de coagulaçãofloculação usando sais de ferro e alumínio, para remoção da matéria orgânica recalcitrante. Operou-se, em paralelo, uma lagoa aerada, em escala de bancada, dimensionada para remoção da matéria orgânica biodegradável cujo efluente era submetido a processo de precipitação química para remoção de amônia, através da formação do mineral estruvita (MgNH4PO4.6H2O). Os resultados obtidos demonstraram que o cloreto férrico (FeCl3) foi o coagulante mais apropriado sob o ponto de vista econômico, embora, dosagens elevadas (1.160 mg FeCl3/L), frente a 2.465 mg Al2(SO4)3.6H2O/L tenham sido requeridas para o alcance de remoções da matéria orgânica recalcitrante. Com a aplicação de FeCl3 o pH ótimo de coagulação foi próximo de 4,0 e para o Al2(SO4)3; por volta de 5,0. Ao longo dos testes, avaliouse a influência das condições de mistura sobre os fenômenos físico-químicos. Os resultados demonstram que, para o despejo estudado, o gradiente de velocidades e o tempo de mistura não exercem influência sobre os fenômenos de coagulaçãofloculação. Quanto à precipitação química da amônia na forma do mineral estruvita, as melhores remoções (~ 90%) foram alcançadas quando o limite de solubilidade do mineral estruvita foi excedido, para tanto se faz necessária aplicar uma razão molar igual a 1,5:1:1,4 entre os íons envolvidos (Mg+2:NH4 +:PO4 -3). Entretanto, o efluente final desse sistema apresentou uma concentração residual de fósforo solúvel superior a 12 mg P-PO4 -3/L, o que o torna pouco recomendável para fins práticos.
Landfill leachates present high ammonia and organic matter concentrations, besides other pollutants, which do not allow its discharge to the environment without a previous treatment. Older landfill leachates, with more stabilized organic matter, present great pollutant potential, mainly due to the presence of recalcitrant substances that not often are removed by biological treatment and need the application of a post-treatment. The present research aimed to apply the physicochemical treatment for two biological wastewater treatment plant effluents. The first one was constituted by an activated sludge (sequence batch reactor - 70 liters), which effluent was submitted to a coagulation-flocculation process, using iron and aluminum salts, for recalcitrant organic matter removal. A lab scale aerated lagoon was operated in parallel. The lagoon was dimensioned for biodegradable organic matter removal, which effluent was submitted to a chemical precipitation process for ammonia removal (formation of the mineral struvite (MgNH4PO4.6H2O).The results showed that the ferric chloride (FeCl3) was the more appropriated coagulant considering the economic point of view, however high dosages (1,160 mg FeCl3/L) comparing with 2.465 mg Al2(SO4)3.6H2O/L had been required to achieve recalcitrant organic matter removal. Applying FeCl3, the optimum pH was of the order of 4.0 and for Al2(SO4)3, approximately 5.0. During the tests, the influence of the mixture conditions on the physicochemical phenomena was evaluated. The results demonstrated that the velocities gradient and the mixture time do not influenced the coagulation-flocculation phenomena. Regarding to the chemical precipitation of ammonia in struvite form, the better removals (~ 90%) were achieved when the solubility limit of the mineral was exceeded. Due to this fact, it was necessary to apply a molar rate of 1.5:1:1.4 between the ions (Mg+2:NH4 +:PO4 -3). Nevertheless, the final effluent of this system presented a residual soluble phosphorus concentration higher than 12 mg P-PO4 -3/L, hence it is not recommended for practical purposes.

Arthrosphira (Spirulina) platensis apresenta substâncias de interesse nas indústrias alimentícia, farmacêutica e cosmética. A produção industrial envolve uma quantidade muito grande de água e sua viabilidade deve contemplar o reuso do meio, visando uma diminuição de custos com nutrientes, bem como da poluição ambiental, tornando-se assim um processo sustentável. O presente trabalho teve como objetivo principal a avaliação do reaproveitamento do meio no cultivo de A. platensis usando tratamentos físico-químicos de floculação e adsorção. Para tanto, tal cianobactéria foi cultivada em fotobiorreator (FBR) tubular em processos de batelada alimentada e contínuo em intensidade luminosa de 120 µmol fótons m-2 s-1, sob controle de pH. Foram desenvolvidas técnicas de tratamento de meio de cultivo proveniente de processo descontínuo alimentado de A. platensis para a remoção de matéria orgânica (MO) e pigmentos (60 - 96 %), permitindo assim seu reuso em novos cultivos. A. platensis foi cultivada nos meios tratados utilizando frascos Erlenmeyer, com avaliação de parâmetros como concentração celular máxima (Xm), conteúdo de clorofila-a (Chl) e conteúdo de proteína na biomassa seca (PTN). No processo simultâneo de floculação e adsorção com carvão ativado em pó (CAP), foram testados dois agentes floculantes, cloreto férrico (F) e sulfato férrico (S) bem como diferentes tempos de contato. No processo simultâneo de floculação com F e adsorção com CAP, as condições ótimas foram: CAP = 24,4 mg L-1 e F = 20,3 mg L-1durante 30,4 min de tempo de contato; com obtenção de: Xm = 4893 ± 33 mg L-1, Chl = 24,3 ± 0,1 mg g-1, PTN = 36,1 ± 0,6 %. As condições ótimas de tratamento simultâneo de floculação com S e adsorção com CAP foram: CAP = 40,0 mg L-1 e S = 32,8 mg L-1 durante 36,1 min de tempo de contato, com obtenção de: Xm = 4863 ± 64 mg L-1, Chl = 24,5 ± 0,6 mg g-1, PTN = 60,1 ± 0,6 %. No processo sequencial de floculação com F seguido de adsorção com carvão ativado granulado (CAG), as condições ótimas foram atingidas com: CAG = 108,4 g e F = 10,0 mg L-1 durante 30,8 min de tempo de residência; obtendo-se: Xm = 3140 ± 77 mg L-1, Chl = 35,4 ± 0,2 mg g-1, PTN = 44,9 ± 0,0 %. Adicionalmente, os meios tratados nessas condições ótimas de cada tratamento, também foram testados em FBR tubulares, atingindo valores de Xm, Chl e PTN maiores do que os obtidos com meio padrão. Além disso, o processo simultâneo de cultivo celular em FBR tubulares e adsorção contínua do meio de cultivo exaurido em coluna de CAG removeu 51 - 79 % de MO e pigmentos. Foi demonstrado que uma proporção de 75 % de meio tratado no meio de alimentação não produz diminuição significativa de produtividade celular (PX) e os resultados foram: concentração celular em estado estacionário (Xs) de 1568 ± 15 mg L-1, PX = 941 mg L-1 d-1, PTN = 42,0 ± 0,6 %, com diminuição de 65 % no custo de meio de cultivo. Por fim, conclui-se que é viável a utilização de processos físico-químicos no tratamento de meio a ser reaproveitado no cultivo de A. platensis, inclusive em FBR tubulares, com apreciável incremento de clorofila-a e proteínas na biomassa obtida em meio tratado.
Arthrospira (Spirulina) platensis have compounds of interest in the food, pharmaceutical and cosmetic industries. Industrial production involves high volumes of water and its viability should contemplate medium reuse, aiming to reduce not only nutrient costs, but also environmental pollution, thus becoming a sustainable process. This work had as main objective the evaluation of A. platensis culture medium reuse through the physicochemical treatments flocculation and adsorption. Thus, this cyanobacterium was cultivated in tubular photobioreactor (PBR) by fed-batch and continuous processes at light intensity 120 µmol photons m-2 s-1 under pH control. Treatment techniques were developed for culture medium from fed-batch process to properly removal of organic matter (OM) and pigments (60 - 96 %), thus allowing its reuse in new cultures. A. platensis was cultivated in treated medium using Erlenmeyer flasks, with the evaluation of parameters such as maximum cell concentration (Xm), chlorophyll content (Chl) and protein content in dry biomass (PTN). For simultaneous flocculation and adsorption with powdered activated carbon (PAC), two flocculants were used: ferric chloride (F) and ferric sulfate (S), as well as different contact times. In the simultaneous process of F flocculation and PAC adsorption, optimum conditions were: PAC = 24.4 mg L-1 and F = 20.3 mg L-1 for 30.4 min contact time; results were: Xm = 4893 ± 33 mg L-1, Chl = 24.3 ± 0.1 mg g-1, PTN = 36.1 ± 0.6 %. Optimal conditions in the simultaneous process of S flocculation and PAC adsorption were: PAC = 40.0 mg L-1 and S = 32.8 mg L-1 for 36.1 min contact time; results were: Xm = 4863 ± 64 mg L-1, Chl = 24.5 ± 0.6 mg g-1, PTN = 60.1 ± 0.6 %. In the sequential process of F flocculation followed by adsorption with granular activated carbon (GAC), optimal conditions were reached at GAC = 108.4 g and F = 10.0 mg L-1 for 30.8 min of residence time, at which Xm = 3140 ± 77 mg L-1, Chl = 35.4 ± 0.2 mg g-1 and PTNPTN = 44.9 ± 0.0 % were obtained. Moreover, medium treated at each optimal condition were also tested in tubular PBRs, reaching values of Xm, Chl and PTN higher than those obtained with standard medium. Furthermore, the simultaneous process of cell cultivation in tubular PBR and continuous adsorption of spent cultivation medium through GAC column removed 51 - 79 % of OM and pigments. It was showed that 75 % of treated medium in the feed medium does not cause significant decrease in cell productivity (PX) and results were: steady-state cell concentration (Xs) = 1568 ± 15 mg L-1, PX = 941 mg L-1 d-1, PTN = 42.0 ± 0.6 %, with 65 % reduction in medium price. At last, it can be inferred that the use of physicochemical processes in medium treatment is feasible for reuse in A. platensis cultivation, including that in tubular PBR, leading to considerable increase in chlorophyll and protein contents of the biomass obtained with treated medium.

Tendo em vista a potencialidade da remoção de algas utilizando a flotação por ar dissolvido, foi proposto o desenvolvimento de um equipamento de laboratório de fácil operação e manutenção, denominado Floteste, integrando as características geométricas do equipamento Jarteste neste trabalho. Foram realizados ensaios, utilizando água sintética contendo algas da ordem de 108 ind/L e natural proveniente de curso d\'água eutrofizado, possibilitando o aprimoramento do estudo das condições de coagulação, mistura rápida, floculação e flotação. Também, ensaios de flotação seguida de filtração em areia foram feitos visando melhorar a qualidade da água flotada. O jarro do Floteste possui placa de orifícios que proporciona perda de carga suficiente para a distribuição uniforme de água saturada pela seção quadrada do mesmo. Concluiu-se que, principalmente, que a dosagem de coagulante e o respectivo pH de coagulação, tempo e gradiente de velocidade médio de mistura rápida, tempo e gradiente de velocidade médio de floculação, tempo e pressão de saturação e a quantidade de ar fornecido exercem influência significativa na remoção de algas, turbidez, cor verdadeira e do número de partículas nos dois tipos de águas estudadas.
Due to the potentiality of the algae removal by dissolved air flotation, it was proposed the development of an equipment in laboratory scale of easy operation and maintenance, dominated Floteste, integrating the geometric characteristics of the Jarteste equipment in this work. Tests were carried out with synthetic water containing a high concentration of algae (~108 ind/L) and natural water from and eutrophicated source. Besides several improvements in the equipment developed in this study, the rapid mixing can be considered the most important, followed by flocculation and flotation. Also, flotation and sand filtration tests were performed to simulate the floto-filtration technology. The Flotateste vessel have a perforated plate that provides enough loss of load in order to uniform the distribution of saturated water in the bottom. It was concluded, mainly, that the coagulant dose and the pH of coagulation, time and velocity gradient of rapid mixing, time and velocity gradient of flocculation, time and saturation pressure chamber and the amount of air supplied played a significant role in the removal of algae, turbidity, true color and of the number of particles in the two types of water studied.

Este trabalho teve como propósito investigar a cinética de floculação de água bruta com baixa turbidez, utilizando o sulfato de alumínio (Al2(SO4)3o18H2O) e o cloreto férrico (FeCl3o6H2O) como coagulantes. Os resultados experimentais foram obtidos em ensaios de \"jar test\". A água bruta utilizada nos ensaios foi preparada em laboratório, simulando um manancial superficial eutrofizado contendo células da cianobactéria Microcystis aeruginosa. Foram testadas 5 dosagens distintas de cada coagulante, 3 valores de G, 2 valores de TAS e 12 tempos de floculação. Utilizou-se a turbidez como medida principal de avaliação dos resultados experimentais. O valor de turbidez inicial (N0) foi corrigido, levando-se em consideração o acréscimo de turbidez em função das dosagens de coagulante. Determinou-se que as dosagens mais efetivas, em termos de remoção de turbidez, foram 20 mg.L-1 para o sulfato de alumínio e 40 mg.L-1 para o cloreto férrico (ambas expressas como massa de coagulante). Para ambos os coagulantes, constatou-se que G = 20 s-1 e TAS = 27 m3.m-2.dia-1 resultaram nas melhores eficiências de remoção de turbidez. Verificou-se também a variação do potencial zeta em função das dosagens de coagulante. Observou-se que o aumento da dosagem de coagulante leva à redução do potencial zeta, aproximando-o do ponto isoelétrico. Porém, o ponto isoelétrico não necessariamente coincide com a melhor eficiência em termos de remoção de turbidez. Com base nos resultados experimentais, foi proposta uma modificação ao modelo clássico da cinética de floculação de suspensões coloidais. Nesta, foi incluso um segundo termo referente à ruptura de flocos (quebra irreversível). O ajuste do modelo proposto foi obtido através de procedimentos de iteração numérica computacional com a função \"Solver\" do programa Microsoft Excel®. Foram calculados os valores das constantes KA, KB e KC do modelo proposto. Amostras do lodo gerado nos ensaios de cinética de floculação foram caracterizadas visualmente através de microscopia eletrônica de varredura (MEV).
The purpose of this work was to investigate flocculation kinetics of low-turbidity raw water, using aluminum sulfate (Al2(SO4)3o18H2O) and ferric chloride (FeCl3o6H2O) as coagulants. Experimental results were obtained in jar tests. Raw water used in the jar tests was prepared in laboratory, simulating a eutrophic natural water source containing cells of the cyanobacteria Microcystis aeruginosa. 5 different coagulant doses were tested for each coagulant, 3 G values, 2 SLR values and 12 flocculation times. Turbidity was selected as the major parameter for experimental results analysis. Initial turbidity values (N0) were corrected taking into account turbidity increase due to coagulant dosing. In terms of turbidity removal, it was determined that the most effective dosage for aluminum sulfate was 20 mg.L-1, and for ferric chloride, 40 mg.L-1 (both expressed as coagulant mass). For both coagulants, it was found that G = 20 s-1 and SLR = 27 m3.m-2.day-1 resulted in the best turbidity removal efficiencies. Zeta potential variation, due to coagulant dosing, was also verified. It was noted that increasing coagulant dosing led to zeta potential reduction, bringing it closer to the isoelectric point. However, the isoelectric point does not necessary coincides with the best turbidity removal efficiency. Based on the experimental results, it was proposed a modification to the classic colloidal suspension flocculation kinetics model. In this modification, a second term regarding floc rupture (irreversible breakage) was included. Through computer numeric iteration using Microsoft Excel®\'s \"Solver\" function, the proposed model adjustment was obtained. Kinetics constants KA, KB e KC values, from the proposed model, were calculated. Sludge samples, generated during flocculation kinetics tests, were visually characterized through scanning electronic microscopy (SEM).

Os compostos (coloidais, suspensos e solúveis) presentes na água residual possuem diferentes características físico-químicas e diferentes massas moleculares. Pesquisadores têm se dedicado ao entendimento mais específico da parte solúvel do efluente. O fracionamento das substâncias orgânicas em diferentes classes e diferentes tamanhos é um dos métodos utilizados para a caracterização dos compostos orgânicos da água residual. Acredita-se que este método possa detectar as alterações nos valores residuais dos compostos orgânicos de forma mais precisa que os métodos tradicionais, i.e. DBO e DQO. Sendo assim, e sabendo do crescente uso dos projetos de pós-tratamento dos efluentes de ETE e reúso destes, fica a clara a avaliação da eficiência dos processos de pós-tratamento e a importância da quantificação e caracterização da matéria orgânica residual no efluente pós-tratado. Os objetivos deste projeto de pesquisa foram avaliar a remoção da carga orgânica residual no efluente do tratamento biológico do processo de lodo ativado da ETE Jesus Netto, utilizando diferentes parâmetros de coagulação/floculação utilizando cloreto férrico, sulfato de alumínio e cloreto de polialumínio como coagulantes, e análise de carbono orgânico dissolvido juntamente com a técnica de distribuição da massa molecular para avaliar essa remoção. As análises mostraram uma redução dos compostos orgânicos presentes no efluente secundário, em termos de carbono orgânico dissolvido, da ordem de 45% para o cloreto férrico e 38% para os sais de alumínio. A distribuição da massa molecular também sofreu alterações, notando-se o aumento dos compostos de menor massa molecular e a redução dos compostos de maior massa molecular. Os resultados corroboram com outros estudos realizados com efluentes secundários e águas de abastecimento sobre o impacto dos processos físico-químicos na distribuição da massa molecular.
The compounds (colloidal, suspended and soluble) present in the waste water have different physicochemical characteristics and different molecular masses. Researchers have dedicated themselves to the more specific understanding of the soluble part of the effluent. The fractionation of the organic substances in different classes and different sizes is a method widely used for the characterization of the organic compounds of the residual water. It´s believed that this method can detect changes of organic compounds residual values more accurately than traditional methods, i.e. biological oxygen demand and chemical oxygen demand. Therefore, knowing the increasing use of WWTP effluent after post-treatment processes and their reuse, it is clear that the evaluation of the post-treatment efficiency and the importance of the quantification and characterization of the residual organic matter in the post-treated effluent. The objectives of this research project were to evaluate the removal of the residual organic matter in the effluent from the biological treatment of the activated sludge process of the Jesus Netto WWTP using different coagulation/flocculation parameters with ferric chloride, aluminium sulfate and polyaluminum chloride (PAC) as coagulants, and dissolved organic carbon and molecular mass distribution analyses to evaluate the organic matter removal. The analyzes showed a reduction of the organic matter present in the secondary effluent, in terms of dissolved organic carbon, up to 45% for ferric chloride and 38% for aluminum salts. The distribution of the molecular mass also changed, with the increase of the compounds of lower molecular mass and the reduction of the compounds of higher molecular mass. The results corroborate with other studies carried out with secondary effluents and water supply on the impact of physicochemical processes on the molecular weight distribution.

A proposta deste trabalho foi utilizar quatro diferentes coagulantes - sulfato de alumínio, cloreto férrico, hidroxicloreto de aluminio e sulfato ferrico; construir os diagramas de coagulação; e assimilar as regiões de maior ou menor eficiência da remoção de turbidez ou da cor. Para permitir uma avaliação de custos na utilização dos coagulantes, observo-se nos diagramas as regiões onde os valores de turbidez remanescente são aproximadamente iguais para diferentes coagulantes. Com essa consideração, foi stabelecida a relação entre consumo e custo dos produtos quimícos utilizados. Os coagulantes que apresentaram particularidades para as águas estudadas foram: o cloreto ferrico que mostrou melhor desempenho para valores de ph baixos; o sulfato ferrico que mostrou-se mais economico; e o hidroxicloreto de aluminio que atua numa grande faixa de ph. Na conclusão dos estudos, verifica-se que cada água a ser tratada deve ser analisada através de diagramas de coagulação, visando a otimização dos parâmetros de ph versus dosagem e buscando o melhor coagulante pelo menor custo.
The purpose of this study was to use four different coagulants - aluminum sulphate, iron chloride, polyaluminum hidroxichloride and ferric sulphate; to build the coagulation diagrams; and to mark the regions of higher or lower efficiency in the removal of turbidity or color. To allow a cost appraisal in the use of the coagulants, the region where the values of remaining turbidity, which are approximately the same for different coagulants, was examined in the diagrams. This being taken into consideration, the relation between consumption and cost of the chemical products was established. The coagulants that presented certain peculiarities for the studied waters were: iron chloride, that showed better performance for low pH values; the ferric sulphate, that showed itself as more economical; and the polyaluminum hidroxichloride, that functions in a large interval of pH. In the conclusion of the study, it was observed that each type of water to be treated must be analyzed through coagulation diagrams, aiming at the optimization of pH parameters versus dosages and looking for the best coagulant with lower cost.

A presente pesquisa teve por objetivo a investigação da influência do tamanho de partículas floculadas na eficiência da clarificação de águas para abastecimento por flotação por ar dissolvido (FAD) com o emprego de método e equipamento para a aquisição e análise de imagens especialmente desenvolvidos, tendo em vista à caracterização da distribuição de tamanho de flocos e microbolhas de ar, bem como, o estudo dos aglomerados bolhas-floco (em termos de número de microbolhas de ar aderidas e velocidade ascensional) presentes no processo de flotação e comparação dos dados experimentais àqueles obtidos em simulação com o emprego do modelo matemático proposto por Reali (1991). Os ensaios foram realizados com água sintética (turbidez de 7,5±0,2 NTU; cor aparente de 38±1 uC; alcalinidade de 29,8±0,6 mg\'CA\'CO IND.3\'/L; condutividade de 59,3±0,8 \'mü\'S/cm; UV254nm de 0,128±0,004 \'CM POT.-1\'), a qual foi coagulada com a aplicação de 1,9 mg/L de \'AL POT. 3+\' (pH de 6,6±0,05) e divididos em duas Fases: Fase 1 - ensaios preliminares realizados em escala de laboratório, com o emprego do flotateste; Fase 2 - ensaios realizados em unidade piloto de flotação. Os resultados alcançados demonstraram que: i) a distribuição de tamanho de partículas floculadas influenciou diretamente a clarificação por flotação da água em estudo, sendo que as melhores condições de floculação foram aquelas que conduziram à formação, em sua maioria, de partículas floculadas com diâmetro médio de Feret acima de 300 \'mü\'m; ii) os menores valores residuais dos parâmetros analisados na água em estudo foram alcançados com o emprego do tempo de floculação de 17 min, entretanto a FAD foi capaz de operar também com boa eficiência com a utilização de tempo de floculação de 10 min; iii) o método e equipamento desenvolvidos nesta pesquisa para a aquisição e análise de imagens demonstraram constituir importantes ferramentas para a obtenção das distribuições de tamanho de flocos e microbolhas de ar, bem como, para a determinação do número de microbolhas de ar aderidas às superfícies dos flocos e da velocidade ascensional dos aglomerados bolhas-floco gerados no processo de flotação; iv) mesmo com as diversas simplificações adotadas no desenvolvimento do modelo matemático analisado e considerando as condições experimentais utilizadas nesta pesquisa, foi possível verificar para a água em estudo e para as condições operacionais empregadas nesta pesquisa, que a modelação matemática proposta por Reali (1991) foi capaz de fornecer subsídios para uma adequada estimativa do número de microbolhas de ar aderidas aos flocos, bem como, das velocidades ascensionais dos aglomerados bolhas-floco.
The goal of this research was to investigate the flocculated particles size distribution influence on the dissolved air flotation (DAF) efficiency. Special image acquisition method and equipment were used to characterize the flocculated particles and air microbubbles size distribution, as well as, the clusters (in terms of microbubbles number adhered and rise velocity) in the contact zone outlet of the DAF unit. Besides that, the experimental results were compared with those obtained from the DAF modeling proposed by Reali (1991). The trials were carried out with synthetic water (temperature of 26.0 ± 0.5oC; turbidity of 7.5±0.2 NTU; apparent color of 38±1 CU; alkalinity of 29.8±0.6 mg\'CA\'\'CO IND.3\'/L; conductivity of 59.3±0.8 \'mü\'S/cm; UV254nm of 0.128±0.004 \'CM POT.-1\'), that it was coagulated by applying 1.9 mg/L of \'AL POT.3+\' (22.5 mg/L alum). The trials were divided into two phases: Phase 1 - preliminary tests carried out in laboratory facilities (flotatest); Phase 2 - tests carried out in pilot facilities (DAF pilot unit). The results showed that: i) the flocculation conditions interfered directly on the efficiency of DAF process, and the best flocculation conditions were those that conducted to formation of flocculated particles size with Feret mean diameter above 300 \'mü\'m; ii) the best results were obtained applying flocculation time of 17 min, however, DAF was also capable of operating with a satisfactory efficiency when applying flocculation time of 10 min; iii) the special image acquisition method and equipment developed in this research proved to be a important tool to characterize the flocculated particles and air microbubbles size distribution, as well as, the number of air microbubbles adhered to the flocs surface and the clusters rise velocity; iv) the DAF modeling developed by Reali (1991) provided a reliable prediction of the microbubbles number adhered to the flocs surface, as well as, the clusters rise velocity.

A constante exploração dos recursos hídricos para os mais diferentes usos sem um planejamento adequado, tem levado ao comprometimento desses recursos, verificando-se cada vez mais aumento no número de pesquisas e investimentos, visando o estudo de alternativas que viabilizem o tratamento avançado de águas residuárias e sua reutilização. Entre essas alternativas, estão as técnicas de separação dos materiais contaminantes por membranas. Neste trabalho estudou-se a viabilidade da utilização da microfiltração tangencial como alternativa de pós-tratamento de efluente de Reator Anaeróbio de Leito Expandido alimentado com esgoto sanitário, analisando-se a influência da utilização de cloreto férrico como coagulante, bem como, membranas com diferentes tamanhos de poro (0,2 e 1,0 μm), no desempenho da microfiltração tangencial. Os ensaios no sistema de microfiltração tangencial foram realizados em batelada, com amostras de efluente do reator anaeróbio de leito expandido (RALEX). Verificou-se que para os ensaios realizados com a membrana de 0,2 μm, o aumento das dosagens de cloreto férrico, contribuiu para diminuição nos valores de luxo de permeado. Esta relação não ocorreu de forma direta com a membrana de 1,0 μm. Os processos de coagulação e floculação foram essenciais para ambas membranas no aumento na eficiência de remoção da demanda química total de oxigênio (mg/l), fosfato total (mg P/l) e turbidez, no entanto, em relação aos valores de fluxo do permeado,foi prejudicial, pois nos ensaios em que as amostras de efluente do RALEX não foram previamente coaguladas e floculadas, a permeabilidade das membranas foi bem maios. O sistema de microfiltração tangencial operando com a membrana de 0,2 μm apresentou melhor desempenho, com valores de fluxo do permeado, em geral superiores a 100 L/m2.h, eficiência de 100% na remoção de coliformes totais e fecais, e a dosagem de 40 mg/l de cloreto férrico, já foi suficiente para uma eficiência média de remoção de DQOt de 95%; P.PO4-3 (89,5%) e Turbidez (96,4%). Portanto, a microfiltração tangencial pode ser considerada uma alternativa eficaz como unidade de pós-tratamento de efluente de reator anaeróbio de leito expandido, produzindo efluente que atende os padrões de reuso na agricultura, para coliforme totais e fecais.
The constant exploration of water resources for the most different uses, without an appropriate planning, has lead to the exhaustion of this resources. This scenery has showed the need of increasing researches and investments on alternative forms of wastewater treatment. This work studied the viability of using crossflow microfiltration as an alternative form of advanced treatment of effluents of Anaerobic Reactor Expanded Bed feed with sewage, examining the effect of the use of ferric chloride as coagulam, as well as of different pore size membranes (0,2 and 1,0 μm) on the performance of crossflow microfiltration. The experiments on crossflow microfiltration system were carried out in batch, using effluent samples of anaerobic reactor expanded bed. The results obtained with the 0,2 μm membrane showed that the increase of ferric chloride dosages contributed for the reduction on flux values. The 1,0 μm membrane did not presented this relation. The flocculation and coagulation processes were essentials for increasing the removal efficiency of Total Chemical Oxygen Demand, Total Phosphorus and Turbidity for both membranes, however, for the flux values the effect was harmful, because when the samples of the Anaerobic Reactor Expanded Bed were not previously coagulated and flocculated, the membranes penneability were higher. The Crossflow Microfiltration System, operating with the 0,2 μm membrane, presented better performance, with flux values generally superior than 100 L/m2.h, efficiency around 100% on the removal of Total and Fecal Coliforms. For this membrane (0,2 μm) the dosage of 40 mg/l of FeCl3 (first stage) was enough for an average of removal efficiency of Total Chemical Oxygen Demand (95%); Turbidity (96.4%); and P.PO4-3 (89,5%). Therefore, crossflow mocrofiltration can be considered an effective alternative for advanced treatment of effluents of Anaerobic Reactor Expanded Bed, producing a final effluent with large potentiality to be used in agriculture.

Esta pesquisa teve como objetivo analisar a remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. em água de abastecimento utilizando a tecnologia de tratamento de ciclo completo com flotação (coagulação, floculação, flotação e filtração) em escala de bancada e utilizando cloreto de polialumínio – PAC como coagulante. Para isso, o método de floculação em carbonato de cálcio – FCCa com e sem a separação imunomagnética – IMS foi utilizado para quantificação dos organismos. Os resultados mostraram que as etapas de coagulação, floculação e flotação (Fase1) removeram 1,55 log de cistos de Giardia spp. e 1,21 log de oocistos de Cryptosporidium spp. O tratamento apenas com filtração (Fase 2) removeu 1,2 log de cistos de Giardia spp. e 0,88 log de oocistos de Cryptosporidium spp. A combinação dos tratamentos (Fase 3) foi capaz de remover 2,64 log de cistos de Giardia spp. e 2,5 log de oocistos de Cryptosporidium spp. Na quantificação de protozoários, o método de FCCa sem IMS demonstrou ser mais econômico e com melhor recuperação do que com IMS. Também foi analisada a influência da terceira dissociação ácida no método com IMS e tal procedimento acarretou em diferenças significativas nos resultados. Mesmo atendendo aos padrões de potabilidade, o tratamento estudado não removeu completamente os protozoários, este fato demonstra a necessidade da preservação dos mananciais, do tratamento dos esgotos e da desinfecção final para maximizar as barreiras que permitam reduzir o risco microbiológico presente na água de consumo.
This research aimed to analyze the removal of Giardia spp. cysts and Cryptosporidium spp. oocysts in drinking water using the full cycle of treatment with flotation technology (coagulation, flocculation, flotation and filtration) at bench scale and using polyaluminum chloride - PAC as coagulant. For this, the flocculation in calcium carbonate - FCCa method with and without immunomagnetic separation - IMS was used for quantification of organisms. The results showed that the stages of coagulation, flocculation and flotation (Step 1) removed 1,55 log Giardia spp. and 1,21 log Cryptosporidium spp. oocysts. Only the treatment with filtration (Step 2) removed 1,2 log Giardia spp. and 0,88 log Cryptosporidium spp. oocysts. The combination of treatment (Step 3) was able to remove 2,64 log Giardia spp. and 2,5 log Cryptosporidium spp. oocysts. In quantifying of protozoa, the FCCa method without IMS proved to be more economical and better recovery than with IMS. It also analyzed the influence of the third acid dissociation in the method with IMS and this procedure resulted in significant differences in the results. Even taking into account the potability standards, the treatment studied didnt completely remove protozoa, this fact demonstrates the need for preservation of water sources, treatment of sewage and final disinfection to maximize the barriers to reduce the microbiological risk present in drinking water.

O uso de polímeros sintéticos como auxiliares de floculação no tratamento de águas para abastecimento é uma prática que vem sendo bastante estimulada. Contudo o uso na floculação visando a flotação de águas para abastecimento tem sido pouco estudado. Neste trabalho, são apresentados os resultados de estudo da influência da aplicação de polímeros sintéticos como auxiliares de floculação na clarificação, por flotação, de água preparada com cor elevada (100 ± 9,0 uC) e baixa turbidez (6,80 ± 1,0 uT). Foram investigados três diferentes tipos de polímeros (catiônico, aniônico e não iônico), aplicados conjuntamente ao coagulante primário (sulfato de alumínio). Após a otimização da dosagem deste coagulante (40 mg/L), sem emprego de polímeros, foi estudado o desempenho da flotação diante a redução da dosagem de coagulante conjugado à aplicação de diferentes dosagens de polímeros. Também foram investigadas a influência do tempo decorrido após a mistura rápida para a adição do polímero, e do tempo e gradiente médio de velocidade na floculação para a flotação. Foram utilizadas duas unidades de flotação por ar dissolvido, uma em escala de laboratório (Flotateste) e outra em escala piloto (com escoamento contínuo). Após a adequação dos parâmetros de floculação, os ensaios obtidos com o flotateste mostraram que a aplicação de 0,25 mg/L de polímero não iônico permitiu a redução de 50% na dosagem de coagulante, sem queda significativa na eficiência de remoção de cor e turbidez (96% e 93% respectivamente). Por sua vez, o polímero catiônico, na dosagem de 0,25 mg/L, possibilitou redução de 70% na dosagem de sulfato de alumínio, com eficiência de remoção de cor e turbidez de 90%. A instalação piloto de flotação operando com TASap de 262 m3/m2d, e aplicação de polímeros, nas condições otimizadas com o flotateste, foi capaz de fornecer bons resultados de remoção de cor aparente (82% e cor no efluente de 18,6 uC) e de turbidez (80% com turbidez de 1,40 uT no efluente). Nos ensaios com a unidade piloto de flotação operando com TASap de 525 m3/m2d, com redução de 70% na dosagem de coagulante (aplicação de 0,25 mg/L de polímero catiônico), observou-se redução de até 79% na massa de Iodo gerada.
The usage of synthetic polymers as flocculation aids for the treatment of supply water is a practice which have been widely stimulated, however its usage in flocculation aiming supply water flocculation has been scarcely studied. This work presents the results of the study of the influence of synthetic polymer application as a flocculation aids for clarifying prepared water containing high levei of color (100 ± 9.0 CU) and low turbidity (6.80 ± 1.0 NTU) through flotation. Three different kinds of polymers were investigated - cationic, anionic and non-ionic - which were applied together with the primary cogulant (aluminium sulphate). After the optimization of this coagulant dosage (40 mg/L), without the utilization of polymers, it was studied the flotation performance by the reduction of the coagulant dosage together with the application of different polymer dosages. It was also studied the influence of the time after rapid mixing for the polymer addition, and of time and average velocity gradient and flotation. Two units of dissolved air flotation were used, a bench unit and a pilot plant unit (with continuous flow). After the flocculation parameters adequacy, the essays obtained with FLOTATESTE showed that the application of 0.5 mg/L of non-ionic polymer allowed a reduction of 50% on coagulant dosage, without meningful drops of the color and turbidity removal efficient (96% and 93% respectively). On the other hand, the cationic polymer, at 0.25 mg/L, enabled a 70% reduction on the aluminium sulphate dosage with color and turbidity removal efficiency of 90%. The plant flotation unit, operating under a flow rate of 262 m3/m2d and with polymer application, under conditions optimized by FLOTATESTE, was able to provide good results of colour removal (82% and effluent color of 18.6 CU) and turbicity removal (83% with turbicity of 1.23 NTU in the effluent). In the essays with the pilot plant flotation unit, operating under a flow rate of 525 m3/m2d after reduction of 70% on the coagulant dosage (application of 0,25 mg/L of cationic polymer) , an up to 79% reduction in mass of sludge generated was observed.

CAPES
A utilização de coagulantes naturais no tratamento de água vem sendo uma alternativa cada vez mais empregada a fim de evitar possíveis danos à saúde e ao meio ambiente causados por determinados coagulantes químicos. A Moringa oleifera é uma árvore de múltiplos usos, cujas sementes possuem uma eficiente atividade como coagulante natural. Entretanto, estudos apontam para uma possível toxicidade deste extrato. Baseando-se nisto, o objetivo do presente trabalho foi o de avaliar a toxicidade de três diferentes extratos de M. oleifera (extrato aquoso, extrato salino da semente integral e extrato salino da semente sem óleo) e da água tratada com os mesmos extratos, frente a duas espécies de microcrustáceos utilizadas como bioindicadoras de toxicidade (Daphnia magna e Artemia salina). Nos ensaios de toxicidade aguda dos extratos utilizando D. magna, verificou-se uma CE50 de 314,05 mg.L-1 para o extrato salino da semente integral e 346,76 mg.L-1 para o extrato salino da semente sem óleo. O extrato aquoso não apresentou toxicidade nem mesmo nas maiores concentrações (400 a 600 mg.L-1). Para o organismo A. salina, nenhum dos extratos mostrou-se tóxico. Nos ensaios realizados com a água tratada com os extratos de M. oleifera, foi encontrada toxicidade para D. magna nas frações sobrenadante (CE50=296,02 mg.L-1) e sedimentada (CE50=291,04 mg.L-1) da água tratada com o extrato salino da semente integral. Para a água tratada com o extrato salino da semente sem óleo, da mesma forma encontrou-se toxicidade nas frações sobrenadante (CE50=351,17 mg.L-1) e sedimentada (CE50=342,32 mg.L-1), o que indica que a toxicidade do extrato não é reduzida após a coagulação/floculação/sedimentação. No teste crônico realizado utilizando organismos de D. magna expostos durante 21 dias ao extrato salino da semente integral de M. oleifera, foram observadas alterações nos parâmetros avaliados (mortalidade, fecundidade e crescimento), sendo que quanto maior a concentração testada, maiores os efeitos tóxicos. Ao término dos 21 dias experimentais, havia ocorrido a mortalidade de 100% dos indivíduos expostos às maiores concentrações (10 e 15 mg.L-1). Além disso, houve grande variação na fecundidade entre os grupos. Com base nestes resultados, é possível afirmar que a utilização de elevadas concentrações do extrato de M. oleifera (acima de 300 mg.L-1) pode causar danos agudos ao organismo D. magna. Entretanto, na prática, as concentrações utilizadas deste coagulante são consideravelmente menores, variando principalmente entre 50 e 150 mg.L-1, de acordo com dados da literatura. Da mesma forma, a diluição que ocorreria no meio hídrico dificilmente proporcionaria que a concentração permanecesse elevada, mesmo que grande quantidade do extrato chegasse ao meio ambiente. Com base nisso, é possível afirmar que o uso do extrato da M. oleifera pode ser incentivado, mas desde que utilizado com cautela, evitando-se concentrações elevadas.
The use of natural coagulants for water treatment has been an alternative increasingly employed in order to avoid possible damage to health and the environment caused by certain chemical coagulants. Moringa oleifera is a multipurpose tree whose seeds have an efficient activity as natural coagulant. However, studies point to a possible toxicity of this extract. Based on this, the objective of this study was to evaluate the toxicity of three different extracts of M. oleifera (aqueous extract, saline extract of the whole seed and saline extract of the seed without oil) and water treated with the same extracts, against two species of microcrustaceans used as bioindicators of toxicity (Artemia salina and Daphnia magna). In acute toxicity tests of the extracts using D. magna, there was an EC50 of 314.05 mg.L-1 for the saline extract of the whole seed and 346.76 mg.L-1 for the saline extract of the seed without oil. The aqueous extract showed no toxicity even at the highest concentrations (400 to 600 mg.L-1). For the organism A. saline, none of the extracts proved toxic. In the tests performed with water treated with the extracts of M. oleifera, toxicity was found for D. magna in the supernatant fractions (EC50=296.02 mg.L-1) and sedimented (EC50=291.04 mg.L-1) of treated water with the saline extract of the whole seed. For the treated water with the saline extract of the seed without oil, was found toxicity in the supernatant fraction (EC50=351.17 mg.L-1) and the sedimented fraction (EC50=342.32 mg.L-1), which indicates that the toxicity of the extract is not reduced after coagulation/flocculation. In the chronic test performed using D. magna exposed during 21 days to the saline extract of the whole seed of M. oleifera, changes in the evaluated parameters (mortality, fertility and growth) were observed, and as higher the concentration tested, bigger was the toxicity. At the end of the 21 experimental days, there had been a 100% mortality of individuals exposed to higher concentrations (10 and 15 mg.L-1). Furthermore, there was wide variation in fertility between the groups. Based on these results, we can say that the use of high concentrations of the extract of M. oleifera (above 300 mg.L-1) can cause acute damage for D. magna. However in practice, the concentrations used of this coagulant are considerably smaller, ranging mainly between 50 and 150 mg.L-1, according to literature data. Likewise, the dilution that occur in the aquatic environment, hardly provide high concentration of the extract in the water bodies. Based on this, we can say that the use of the extract of M. oleifera can be encouraged, but if used with caution, avoiding high concentrations.

Os reatores anaeróbios de tratamento de esgoto possibilitam elevada remoção de matéria orgânica, com menor custo em comparação com os processos aeróbios. Entretanto, esses reatores geralmente são pouco eficientes na remoção de nutrientes e seu efluente pode apresentar valores relativamente elevados de DQO e de sólidos suspensos. Por isso, investigou-se a aplicação de cloreto férrico e auxiliares de floculação no afluente de um reator anaeróbio de leito expandido em escala real (Volume = 32 m3; TDH = 3,2 h), no intuito de elevar as eficiências de remoção de DQO, turbidez, fósforo e sólidos. Foram realizados testes de Atividade Metanogênica para avaliar a toxicidade do cloreto férrico ao lodo do reator, mas nenhum efeito tóxico foi detectado para concentrações de até 500 mg FeCl3/l. Em seguida, foram realizados testes em reator de bancada (jar test), quando foi investigado o uso de cloreto férrico (dosagens entre 40 e 200 mg/l) em conjunto com um polímero catiônico, um polímero aniônico e amido natural de batata (dosagens entre 0,5 e 2,0 mg/l), sendo obtidos os melhores resultados com cloreto férrico e polímero aniônico. As eficiências médias diárias de remoção no reator de leito expandido foram elevadas de 64% para 71%, para DQO; de 47% para 59%, para turbidez; de 17% para 31%, para fósforo; e de 52% para 77%, para SST, quando aplicadas dosagens de 40 mg/l de cloreto férrico e 1,0 mg/l de polímero aniônico.
Anaerobic reactors for wastewater treatment have high capacity in removing organic matter and lower costs in comparison with aerobic processes. Nevertheless, anaerobic reactors generally are less efficient in nutrient removal and their effluents may present relatively high COD and total suspended solid (TSS) concentrations. Hence, the application of ferric chloride (FeCl3) and flocculant aids to a full-scale (Volume = 32 m3; HRT = 3,2 h) anaerobic expanded bed reactor influent was investigated to improve removal of COD, turbidity, phosphorous and solids. Methanogenic activity tests were conducted to evaluate toxicity of ferric chloride against methanogenic anaerobic reactor sludge. Tests showed that no toxic effect occurred before concentrations of FeCl3 reached 500 mg/l. Conventional bench-scale jar tests were conducted and ferric chloride was tested in combination with a cationic polymer, an anionic polymer and natural potato starch. Best results were obtained when ferric chloride was employed with anionic polymer. Average daily removal rates were increased from 64% to 71% for COD, from 47% to 59% for turbidity, from 17% to 31% for phosphorous and from 52% to 77% for TSS when dosages close to 40 mg/l of ferric chloride and 1,0 mg/l of anionic polymer were applied to anaerobic expanded bed reactor influent.

Esta pesquisa avaliou o uso de ozônio para inativar cistos de Giardia spp. e oocistos de Cryptosporidium parvum presentes na água filtrada obtida após a utilização da tecnologia de ciclo completo com flotação (coagulação, floculação, flotação e filtração) em escala de bancada, empregando o cloreto de polialumínio – PAC – como coagulante. O método de floculação em carbonato de cálcio – FCCa, sem e com a etapa de separação imunomagnética – IMS – foi utilizado na quantificação dos protozoários. A recuperação nos ensaios de qualidade utilizando o kit Easyseed® de Giardia spp. foi de 8,4% ± 97,4% sem IMS e com IMS, com duas dissociações, o valor foi de 7,4% ± 39,7% e, com três dissociações, a recuperação alcançou 9,6% ± 34,7%, portanto, somente o ensaio com IMS e duas dissociações, não atendeu os padrões do Método 1623.1. A recuperação de Cryptosporidium parvum, obteve valor de 3,4% ± 100% em ensaio sem IMS e com IMS, o valor obtido foi de 1,0% ± 70,0% com duas dissociações e 1,8% ± 44,4% com três dissociações e nos três métodos apresentados, não houve conformidade com os critérios do Método 1623.1. Na etapa de desinfecção com ozônio, os ensaios realizados na Etapa 1, que se utilizou 5 mgO3L-1 e tempo de contato de 1 min sem IMS, as maiores inativações atingidas foram de 2,52 e 2,22 log para cistos de Giardia spp. e oocistos de Cryptosporidium parvum, respectivamente. Com o tempo de contato de 5 min, as maiores inativações foram de 2,52 e 2,92 log de cistos de Giardia spp. e oocistos de Cryptosporidium parvum, respectivamente. Na Etapa 2, com IMS, utilizando a mesma dosagem e tempo de contato de 1 min, obteve-se 2,27 e 0,21 log de inativação para cistos e oocistos, respectivamente. Comparando-se com o tempo de contato de 5 min, foram obtidos 2,9 e 2,3 log de inativação para cistos e oocistos, respectivamente. Na avaliação de custo, o método de FCCa sem IMS demonstrou ser o mais econômico em relação ao procedimento com IMS. A influência da inclusão da terceira dissociação ácida no método com IMS também foi analisada e este procedimento não resultou em diferenças estatísticas significativas nos resultados.
This research evaluated the use of ozone to inactivate Giardia spp. cysts and Cryptosporidium parvum oocysts present in the filtered water obtained after the use of the complete cycle of flotation technology (coagulation, flocculation, flotation and filtration) on a bench scale employing polyaluminium chloride - PAC as coagulant. The calcium carbonate flocculation method - FCCa, without and with immunomagnetic separation step - IMS has been used in the quantification of protozoa. The recovery in quality test using the kit Easyseed® for Giardia spp. was 8.4% ± 97.4% non-IMS and IMS with two dissociations, the value was 7.4% ±39.7% and with three dissociations, the recovery reached 9.6% ± 34,7%, so only the test with IMS and two dissociations, did not meet the standards of method 1623.1. Recovery of Cryptosporidium parvum obtained value of 3.4% ± 100% in non-IMS and IMS testing, the value obtained was 1.0% ± 70.0% with two dissociations and 1.8% ± 44.4% with three dissociations and the three methods presented, there was non-compliance with the criteria of Method 1623.1. In step disinfection with ozone, tests performed in Step 1 was used 5 mgO3L-1 and contact time of 1 min without IMS, the major inactivation achieved were 2.52 and 2.22 log for Giardia spp. cysts and Cryptosporidium parvum oocysts, respectively. With 5 minutes of contact time, the greater inactivation were 2.52 and 2.92 log for Giardia spp. cysts and Cryptosporidium parvum oocysts, respectively. In Step 2, with IMS, using the same dose and 1 min contact time, there was obtained 2.27 and 0.21 log inactivation for cysts and oocysts, respectively. Compared with the 5 min of contact time, were obtained 2.9 and 2.3 log inactivation for cysts and oocysts, respectively. In evaluating cost, the FCCa method without IMS proved to be the most economical in relation to the procedure with IMS. The influence of inclusion of the third acid dissociation method in IMS was also analyzed and this procedure did not result in statistically significant differences in the results.

碩士
朝陽科技大學
環境工程與管理系碩士班
92
The activated sludge process has been widely used in wastewater treatment. However the process has been suffered by bulking sludge problem, especially for pulping wastewater. Most studies attempt to employ biological methods to inhibit filamentous growth for improvement of the settlability. This study however evaluates the feasibility of ballasted flocculation method from the viewpoint of increasing the biofloc structure with weighing agents (carriers). A 1000-mL graduated cylinder batch procedure was used for the evaluation. The activated sludge was obtained from a typical pulping wastewater treatment plant located in the central Taiwan. In order to simply the test procedure of suspended solid (SS), this study first evaluated whether fiber glass filters could be directly used for filtration without pre-drying. The results indicate that this will underestimate test values by only 0.09 ~ 1.8%, with a higher error for a higher solid residual weight on filters (10 ~ 200 mg). It is determined to be appropriate with skipping the pre-drying procedure for the SS test. This study further evaluated whether parallel settling tests can be replaced by sequential tests to reduce the sample volume of solid suspension. The results indicate that both tests yield a similar settling velocity of 1.92 cm/min at an MLSS of 400 mg/L. Furthermore as MLSS increases from 400 to a typical concentration of 3,000 mg/L, settling velocity determined from the cylinder test will be reduced by 95% due to the wall effect associated with solid flux limitation. The weighing carrier used for this study was determined to have a porosity of 0.25 with a true density of 2.26 g/cm3. Microscopic examination reveals that the carrier has a round shape with a grain size estimated to be 1 ~ 10 μm. The settling velocity was determined to increase by 11.1 and 244% at a carrier dosage of 8.5 and 43% (by weight), respectively. To avoid excessive increase of the waste sludge, carrier should not be added at a dosage more than 20% by weight. It is suggested that a continuous settling test be conducted as a followed study for evaluation of the ballasted flocculation process.

Jar tests are performed to simulate full-scale pre-treatment and particle removal processes. Operators typically conduct them in an effort to attempt alternative treatment doses and strategies without altering the performance of the full-scale drinking water treatment plant. However, information obtained from these tests must be evaluated judiciously, as they currently focus on reduction of specific water quality parameters (i.e., ultraviolet absorption at 254 nm (UV254) and turbidity), and measuring and understanding the significance of coagulant dose on floc size. Consideration of aggregate structure has been less explored due mainly to a lack of appropriate theories to describe the complex random floc structure. Improving the predictive capacity of bench-scale protocols commonly used for optimizing conventional chemical pre-treatment in full-scale drinking water treatment plants is required. Results from settling tests indicated that the production of larger and more settleable flocs could not be described by floc settling velocities and floc sizes. Settling velocities were not directly related to either UV254 or turbidity reductions. Results of the floc characterization tests indicated that measured values of UV254 and turbidity of the supernatant were generally inversely proportional to aggregate D90; that is, the residual UV254 and/or turbidity decreased as the value of D90 increased, which may have been indicative of flocculent settling. No direct relationship could be discerned between fractal dimension D1 (i.e., floc shape) and the UV254 and turbidity of the supernatant; however, the turbidity after flocculation and a period of settling appeared to be inversely proportional to fractal dimension D2 (i.e., porosity). Overall, the results of the experiments have demonstrated that grain size distributions and fractal dimensions might be used to assess and/or predict pre-treatment and/or particle removal performance. Specifically, the relationship between D90 values calculated from samples of flocculated water prior to settling and UV254 and turbidity values of that water after a period of settling may be a simple tool that can be utilized to describe and potentially better predict flocculent settling performance. At present, this appears to be the first such tool of its kind that has been reported.

A study was conducted to evaluate the properties and processes influencing the rate and magnitude of volume decrease and strength gain for oil sand fine tailings resulting from a change in bitumen extraction process (caustic versus non-caustic) and the effect of adding a coagulant to caustic fine tailings. Laboratory flume deposition tests were carried out with the objective to hydraulically deposit oil sand tailings and compare the effects of extraction processes on the nature of beach deposits in terms of geometry, particle size distribution, and density. A good correlation exists between flume deposition tests results using oil sand tailings and the various other tailings materials. These comparisons show the reliability and effectiveness of flume deposition tests in terms of establishing general relationships and can serve as a guide to predict beach slopes. Fine tailings were collected from the various flume tests and a comprehensive description of physical and chemical characteristics of the different fine tailings was carried out. The characteristics of the fine tailings is presented in terms of index properties, mineralogy, specific surface area, water chemistry, liquid limits, particle size distribution and structure. The influence of these fundamental properties on the compressibility, hydraulic conductivity and shear strength properties of the fine tailings was assessed. Fourteen two meter and one meter high standpipe tests were instrumented to monitor the rate and magnitude of self-weight consolidation of the different fine tailings materials. Consolidation tests using slurry consolidometers were carried out to determine consolidation properties, namely compressibility and hydraulic conductivity, as well as the effect of adding a coagulant (calcium sulphate [CaSO4]) to caustic fine tailings. The thixotropic strength of the fine tailings was examined by measuring shear strength over time using a vane shear apparatus. A difference in water chemistry during bitumen extraction was concluded to be the cause of substantial differences in particle size distributions and degree of dispersion of the comparable caustic and non-caustic fine tailings. The degree of dispersion was consistent with predictions for dispersed clays established by the sodium adsorption ratio (SAR) values for these materials. The biggest advantage of non-caustic fine tailings and treating caustic fine tailings with coagulant is an increased initial settlement rate and slightly increased hydraulic conductivity at higher void ratios. Thereafter, compressibility and hydraulic conductivity are governed by effective stress. The chemical characteristics of fine tailings (water chemistry, degree of dispersion) do not have a significant impact on their compressibility behaviour and have only a small influence at high void ratio (low effective stress). Fine tailings from a caustic based extraction process had relatively higher shear strengths than comparable non-caustic fine tailings at equivalent void ratios. However, shear strength differences were small and the overall impact on consolidation behaviour, which also depends on compressibility and hydraulic conductivity, is not expected to be significant.

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.