Polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing polycyclic aromatic compound (N-PAC) are widespread toxic pollutants in environments. The fate of PAHs and N-PACs are of great concern because some of these compounds were identified as caricinogenic, mutagenic and teratogenic compounds. As described in literature, dissolved organic matter (DOM) is an important factor in control of their fate; however, the binding behaviors between these compounds and DOM are still not fully understood. The binding constants (KDOC) between humic substances and one selected N-PAC, benzo[h]quinoline, were measured at varying pH levels using fluorescence quenching (FQ) method. As fluorescence characteristics of benzo[h]quinoline change with pH, determination required two optimum sets of excitation and emission wavelength pairs. A simple mixing model was proposed and used to eliminate the inherent fluorescence interference between benzo[h]quinoline (BQ) and its protonated form, benzo[h]quinolinium (BQH+), and to deduce Kmix which represents the overall binding as the sum of that for the individual analogs. The characteristics of humic substances, especially their hydrophobicity and aromaticity, established by principal components analysis of structural and elemental compositions, were the main determinants of their binding affinity with both benzo[h]quinoline and benzo[h]quinolinium (KBQ and KBQH+) across a range of pH values. Hydrophobic interaction is likely to control the binding between humic substance and benzo[h]quinoline and benzo[h]quinolinium, in lower and higher pH ranges (pH<3, pH>6). In contrast, cation exchange seems to control on the binding affinity of benzo[h]quinolinium in the middle range of pH. Determination of PAH concentration is quite essential for investigating the fate of PAHs in environments. Microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was applied as a single step prior to determination of PAH concentrations in water using GC-MS. To optimize the extraction efficiency of PAHs by MA-HS-SPME, the influence of various parameters, including temperature, duration of thermal desorption, microwave irradiation power and duration, and the temperature of the circulating cooling water system, was studied. The proposed method was demonstrated applicable to environmental water samples. In addition, DOM matrix effect did not influence the determination and extraction efficiency of PAHs. Although the proposed simple mixing model can eliminate the fluorescent interference of hydrophobic organic compounds with acid-base pair forms, it is still limited in using for correcting the KDOC measurement of more than two fluorescent compounds simultaneously. A new alternative protocol, complexation-flocculation combined with MA-HS-SPME/GC-MS method, was proposed to determine the binding constants of seleted PAHs to humic substances. The results obtained are comparable with KDOC data reported in literatures. CF-MA-HS-SPME/GC-MS provides some advantages over other methods, such as applicable not limited to fluorescent compounds, faster in determination and capable in measuring varieties of compounds simultaneously.

This study aims to investigate the possibility of using calcium-alginate as a coagulant in low turbidity waters. Jar tests were initially performed with synthetically prepared turbid waters to investigate the effect of alginate and calcium concentrations, alginate&rsquo / s molecular weight, rapid mixing time and speed (schedule), initial pH and alkalinity of synthetic water on turbidity removal efficiency of calcium-alginate system step by step. Alum as a coagulant was then used in jar tests conducted with synthetic water to compare with calcium-alginate in terms of its turbidity removal efficiency and produced sludge properties. Finally, raw water acquired from water treatment plant was tested for treatability by using calcium-alginate based on previously determined optimum parameters via jar tests. Experiments of calcium-alginate system with synthetic water showed that calcium was a key parameter in coagulation and high molecular weight alginate performed better in turbidity removal. Significant improvements in turbidity removal were observed when mixing schedules were rearranged / especially in case of increasing rapid mixing time following calcium dosing. Calcium-alginate system neither was notably affected by pH or alkalinity nor did significantly change the pH or alkalinity of the medium. Alum worked well in turbidity removal with additional adjustments of pH and alkalinity, however / alum produced higher quantities of sludge than calcium-alginate system. &ldquo / Raw water&ldquo / experiments with calcium-alginate did not result in desired level of turbidity removals due to the excessively different characteristics of this water compared to the synthetically prepared turbid water.

Coagulation and flocculation processes are important parts of water and wastewater treatment. Coagulation or destabilization of colloidal suspensions results in aggregation of colloidal particles by physical and chemical processes. Flocculation results in the formation of larger and settleable structures by bridging. Alginate, a polysaccharide obtained from marine brown algae, produces a gel structure when mixed with calcium ions, which is expected to be a potential coagulant in water treatment. This study aims to determine the use of calcium alginate as a potential coagulant during water treatment and determine its capabilities and deficiencies in coagulation processes. The study was conducted on turbid water samples prepared in the laboratory and those taken from the inlet of Ankara ivedik Water Treatment Plant (IWTP) by running typical jar tests. The main experimental variables were initial alginate and calcium doses, initial turbidity of water samples and the order with which the two chemicals are dosed. The main criteria investigated to check the success of the system was the final turbidity values and the turbidity removal capacity of calcium- alginate. Experiments were conducted on three different laboratory &ndash / prepared turbid water samples and on the raw water taken from the inlet point of Ankara ivedik Drinking Water Treatment Plant (IWTP). These were prepared as high (150 NTU) medium (80 NTU) and low (10 NTU) turbidity samples. The calcium concentrations tested varied between 30 and 200 mg/L and alginate concentrations tested varied between 0.04 to 40 mg/L. Depending on the initial turbidity and initial calcium concentration of water sample the results depict that calcium alginate could be used as an effective coagulant for high (150 NTU) and medium (80 NTU) turbidity water sample especially at the calcium doses of 120 and 160 mg/L for low alginate concentration doses like 0.4 mg/L. The final turbidity met both the requirements of Drinking Water Standards applied in Turkey and Europe. Generally, the higher the initial turbidity was, the higher the turbidity removal efficiency achieved, even with very low alginic acid concentration. As the initial turbidity decreased, initial concentration of calcium required for the effective coagulation processes decreased. However, for low (10 NTU) turbidity water samples the system did not work properlyHowever, for low turbidity water samples, the turbidity removal efficiency decreased, and it was difficult to meet the limits.

The use of polymers as flocculating additives is a common practice in many manufacturing environments. However, exactly how these polymers interact with surfaces is relatively unknown. One specific topic which is thought to be very important to flocculation is an adsorbed polymer's conformation. Substantial amounts of previous work, mainly using simulations, have been performed to elucidate the theory surrounding adsorbed polymer conformations. Yet, there is little experimental work which directly verifies current theory. In order to optimize the use of polymer flocculants in industrial applications, a better understanding of an adsorbed polymer's conformation on a surface beyond theoretical simulations is necessary. This work looks specifically at site blocking, which has a broad impact on flocculation, adsorption, and surface modification, and investigated its effects on the resulting adsorbed polymer conformation. Experimental methods which would allow direct determination of adsorbed polymer conformational details and be comparable with previous experimental results were first determined or developed. Characterization of an adsorbed polymer's conformation was then evaluated using dynamic light scattering, a currently accepted experimental technique to examine this. This commonly used technique was performed to allow the comparison of this works results with past literature. Next, a new technique using atomic force microscopy was developed, building on previous experimental techniques, to allow the direct determination of an adsorbed polymer's loop lengths. This method also was able to quantify changes in the length of adsorbed polymer tails. Finally, mesoscopic simulation was attempted using dissipative particle dynamics. In order to determine more information about an adsorbed polymer's conformation, three different environmental factors were analyzed: an adsorbed polymer on a surface in water, an adsorbed polymer on a surface in aqueous solutions of varying ionic strength, and an adsorbed polymer on a surface functionalized with site blocking additives. This work investigated these scenarios using a low charge density high molecular weight cationic polyacrylamide. Three different substrates, for polymer adsorption were analyzed: mica, anionic latex, and glass. It was determined that, similar to previous studies, the adsorbed polymer layer thickness in water is relatively small even for high molecular weight polymers, on the order of tens of nanometers. The loop length distribution of a single polymer, experimentally verified for the first time, revealed a broad span of loop lengths as high as 1.5 microns. However, the bulk of the distribution was found between 40 and 260 nanometers. For the first time, previous theoretical predictions regarding the salt effect on adsorbed polymer conformation were confirmed experimentally. It was determined that the adsorbed polymer layer thickness expanded with increasing ionic strength of the solvent. Using atomic force microscopy, it was determined that the adsorbed polymer loop lengths and tail lengths increased with increasing ionic strength, supporting the results found using dynamic light scattering. The effect of the addition of site blocking additives on a single polymer's conformation was investigated for the first time. It was determined that the addition of site blocking additives caused strikingly similar results as the addition of salt to the medium. The changes in an adsorbed polymer's loop lengths was found to be inconsistent and minimal. However, the changes in an adsorbed polymer's free tail length was found to increase with increasing site blocking additive levels. These results were obtained using either PDADMAC or cationic nanosilica as site blocking additives.

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.

L'évolution des caractéristiques des particules en suspension au cours de leur transfert au sein des bassins versants est encore mal connue. Ceci limite actuellement notre aptitude à prédire correctement l'érosion ou les flux de matières en suspension (MES) et rend difficile la proposition de pratiques de gestion adaptées aux réglementations en vigueur. A partir d'expériences en milieu contrôlé, nous avons montré que les particules de sols ont tendance à se désagréger en milieu turbulent. Il semble de plus qu'une augmentation de la concentration en suspension accélère cette désagrégation et conduise à des particules plus fines. Même si l'évolution des particules à l'échelle horaire semble rester de second ordre derrière les caractéristiques des sols sources, il est indispensable de pouvoir vérifier si les particules en suspension se comportent de la même manière en conditions naturelles où des interactions complexes entre processus peuvent avoir lieu. Cependant l'absence de méthode de mesure permettant le suivi des propriétés de transport des sédiments en écoulements très concentrés (de 1 plusieurs centaines de grammes par litre) dans les bassins élémentaires limite notre capacité à hiérarchiser les processus à considérer pour modéliser le transfert sédimentaire ou améliorer la gestion opérationnelle des sédiments. Afin de répondre à ce besoin instrumental, nous avons développé un Système de Caractérisation des Agrégats et des Flocs (SCAF). Cet instrument est conçu pour être incorporé dans les stations de suivi hydro-sédimentaire. La mesure est réalisée immédiatement après prélèvement d'un échantillon de la suspension à caractériser par une série de capteurs optiques qui suivent l'évolution de l'absorbance optique durant la sédimentation de l'échantillon. Nous proposons une méthode de traitement des données optiques donnant accès à la distribution des vitesses de chute de la suspension ainsi qu'à un indice de floculation qui renseigne sur la capacité des MES à floculer durant leur sédimentation. Les distributions de vitesses de chute mesurées sont validées sur une large gamme de matériaux et de régimes de sédimentation, afin de couvrir la variabilité des types de matériaux et des concentrations observées en milieu naturel. Pour des sédiments non cohésifs ou floculant peu durant leur sédimentation les mesures du SCAF s'ajustent sur celles issues des autres méthodes. Pour les suspensions qui floculent durant leur sédimentation, la plupart des méthodes de mesure classiques conduisent à des vitesses de chute non représentatives de la suspension. Nous avons montré que les variations des propriétés optiques des matières en suspension lors de leur floculation impactent nos mesures. La méthode proposée permet cependant de quantifier l'augmentation des vitesses de chute avec la floculation, et d'encadrer l'incertitude des mesures. Pour les mesures à forte concentration (>10 g/l), un front d'entravement peut se former durant la sédimentation, le SCAF mesurant alors précisément les vitesses de chute du front. La mesure des distributions des vitesses de chute et de la cohésion des particules en suspension peut permettre d'identifier différentes populations de particules formant une suspension (grains de sables, flocs, matières fines...). Le suivi de telles informations au sein de bassins versants ouvre de nouvelles perspectives pour aborder la connectivité sédimentaire et s'orienter vers une gestion optimale des flux de MES. / Little is known about the processes that govern the evolution of suspended particle characteristics during their transport through a river basin. This is a main limitation for modelling erosion severity or suspended solids (SS) fluxes. It also leads to difficulties to propose management policies adapted to environmental legislation. Based on experiments in controlled environments, we have shown that soil particles tend to disaggregate in turbulent flows. The increase in SS concentration was associated to an increase of the disaggregation of SS particles, leading to smaller final particle sizes. Laboratory experiments also showed that the variability of the particle sizes due to their evolution over one hour was smaller than the variability due to the soil type from which the particles originated. However it is important to ensure that the suspended particles behave in the same way in natural conditions, where complex interactions between hydraulic, chemical and biological processes can influence their evolution. Up to now no measurement method allows measuring continuously the suspended sediment properties in highly concentrated fluids (from one to hundreds grams per liter), such as those observed in headwater catchments during runoff events. This severely limits the possibility to identify the processes that are important to consider in numerical models. The Aggregate and Floc Characterization System (SCAF) has been developed in order to measure SS properties for a wide range of SS concentrations. It was designed to be easily incorporated into sequential samplers. Immediately after the collection of a sample from the river, the sedimentation of the suspension is recorded by continuous measurements of the absorbance by a series of optical sensors. A method was proposed to processes the raw optical data in order to obtain the settling velocity distribution of the suspension. It also provides a flocculation index representing the tendency of the particles to flocculate during their sedimentation. The calculated settling velocity distributions were validated on a large range of materials and settling regimes in order to cover the natural variability of suspended sediments. For sediments that hardly flocculate during their sedimentation or are non-cohesive, the measurements of the SCAF were similar to those from other methods. In the case of suspensions that strongly flocculate during sedimentation, most of the classical methods give non-representative falling velocities. In this case, the optical property of the particles may vary during settling, affecting the optical measurement. The proposed method allowed quantifying the increase of settling velocity induced by flocculation, and provided confidence intervals for the settling velocities. For high SS concentrations ( > 10 g/l), a settling front can be formed during the sedimentation, which is well characterized by the SCAF. The measurement of the settling velocity distributions and of the flocculation index can be used to identify different particle populations (sand grains, flocs, individual particles) forming a suspension. Monitoring these properties in watersheds offers new insights to explore sediment connectivity within river basins and to optimize water management strategies.

A indústria têxtil utiliza elevados volumes de água em seus processos, principalmente na etapa de tingimento, em que são utilizadas também quantidades elevadas de corantes e auxiliares têxteis. A presença desses produtos no efluente gera um efeito prejudicial e claramente visível ao ambiente, pois causam alteração nos parâmetros da qualidade da água do corpo receptor. O presente estudo apresenta o pós-tratamento de um efluente têxtil, objetivando o reciclo deste efluente para água de processo de tingimento. Para isso foi utilizada uma combinação de processo físico-químico de coagulação/floculação (CF) e processo de separação por membrana (PSM) de Ultrafiltração (UF) e Osmose Inversa (OI). Os parâmetros analisados antes e após os tratamentos foram: turbidez, condutividade elétrica, demanda química de oxigênio (DQO), carbono orgânico total (COT) e cor. Na etapa de CF foram testados dois tipos de coagulantes, o Sulfato de Alumínio e o Cloreto Férrico, nas concentrações de 30, 50, 70 e 100 mg.L-1. Foram testadas três concentrações de floculante comercial: 0,2, 0,3 e 0,4 mg.L-1. Os experimentos foram conduzidos em pH 7. As etapas de PSM foram conduzidas em módulo plano de Ultrafiltração e em módulos plano e espiral na membrana de Osmose Inversa. O melhor desempenho foi obtido com a dosagem de 50 mg.L-1 do coagulante cloreto férrico e a de 0,3 mg.L-1 de floculante comercial, que apresentou uma redução de 98% na turbidez com relação ao efluente de alimentação. No PSM de Ultrafiltração a remoção de cor não foi satisfatória por ainda apresentar coloração. No PSM de Osmose Inversa com o módulo plano o objetivo da remoção de cor foi atingido com sucesso na análise visual, porém, a vazão de permeado mostrou-se muito baixa inviabilizando o processo. No PSM de Osmose Inversa em módulo espiral a cor foi removida com sucesso, a turbidez ficou abaixo de 1 NTU, a DQO ficou abaixo do limite de detecção do equipamento e a vazão de permeado foi satisfatória. Assim, o estudo aponta como resultado a aplicação CF combinado à OI no tratamento eficaz deste efluente. / The textile industry uses large volumes of water in their processes, especially in the dyeing step, which are also used large quantities of coloring agents and textile auxiliaries. The presence of these products in the effluent generates a harmful effect and clearly visible to the environment because they cause changes in the parameters of the receiving body of water. This paper presents the post-treatment effluent from a textile industry, in order to recycle it as process water for dyeing. A combination of physico-chemical process were carried out applying coagulation / floculation (CF) and Ultrafiltration (UF) membrane separation process (MSP) and reverse osmosis (RO). The parameters analyzed before and after treatments were: turbidity, electrical conductivity, chemical oxygen demand (COD), total organic carbon (TOC) and color. In CF stage two types of coagulants were tested, aluminum sulphate and ferric chloride at concentrations of 30, 50, 70 e 100 mg.L-1. Three concentrations of commercial floculants were evaluated: 0,2, 0,3 e 0,4 mg.L-1. The experiments were conducted at pH 7. MSP steps were conducted in plan Ultrafiltration module, and in the Reverse Osmosis membrane, plan and spiral modules were tested. The best performance was obtained with a dosage of 50 mg.L-1 of the coagulant ferric chloride and 0.3 mg.L-1 commercial flocculant, which showed a 98% reduction in turbidity in respect to the raw effluent. MSP Ultrafiltration color removal was not satisfactory because color was still present. In MSP Reverse Osmosis using the plan module the goal of color removal was successfully achieved in the visual analysis, however, the membrane flow was extremely low compared with the UF permeate flow and prevented the process. The color in MSP Reverse Osmosis spiral module has been successfully removed, the turbidity was below 1 NTU, the COD was below the detection limit of the the equipment and the permeate flow was satisfactory. In this way, the study showed the best application for this effluent is CF combined with RO.

A forma de tratamento e destinação final ainda mundialmente preponderante para os resíduos sólidos urbanos é o aterro sanitário, método que gera, além de uma massa sólida residual, parcialmente estabilizada, subprodutos finais líquidos e gasosos. O efluente líquido, conhecido como lixiviado, necessita tratamento específico, devido a sua elevada nocividade ao meio ambiente, em função, principalmente, de suas elevadas concentrações de nitrogênio amoniacal e de matéria orgânica, em elevado percentual, recalcitrante. O presente trabalho avaliou em escala de bancada o tratamento, via processo físico-químico, através de coagulação-floculação, de lixiviado bruto proveniente de aterro sanitário Central de Resíduos do Recreio (operado pela Companhia Riograndense de Valorização de Resíduos), desprovido de qualquer tratamento prévio, e de lixiviado pré-tratado biologicamente em reatores sequenciais em batelada (RSB). Para o processo de coagulação-floculação foram testados os coagulantes policloreto de alumínio (PAC), cloreto férrico, sulfato férrico e tanino. Sucessivas etapas foram planejadas para a determinação de dosagem e ajuste de pH ótimos, para cada coagulante empregado, e para a verificação da influência de tempos e gradientes de misturas, bem como foi testada a aplicação de polímeros auxiliares de floculação. As variáveis resposta utilizadas para o monitoramento e a avaliação de eficiências foram a cor verdadeira, turbidez (com e sem prévia filtração), DQO, volume de lodo gerado e pH. O uso de reator sequencial em batelada objetivou nitrificação/desnitrificação convencional das elevadas concentrações de nitrogênio amoniacal e eventual oxidação de matéria carbonácea. Verificou-se que os diferentes tempos e gradientes de mistura testados, assim como a utilização de polímeros auxiliares, não produziram impactos nos resultados. Os coagulantes inorgânicos apresentaram elevadas eficiências de remoção, com destaque para o cloreto férrico, o qual na dosagem de 1102 mgFe+3/L e ajuste inicial de pH em 6,2 removeu 98% da cor verdadeira e da turbidez filtrada, 63% da DQO, 40% da DBO5, e 88% de turbidez não filtrada do lixiviado bruto. Apesar da recalcitrância de considerável fração da matéria orgânica do lixiviado, o RSB2 removeu 40% da DQO e 60% da DBO5 originais. A coagulação-floculação do efluente do RSB2 necessitou inferiores dosagens dos coagulantes em relação ao processo com lixiviado bruto. O cloreto férrico, em dosagem ótima de 826 mgFe+3/L e ajuste de pH em 6,3, removeu 95% da cor, 77% da DQO, 82% da DBO5, 94% da turbidez filtrada e 92% da turbidez não filtrada. Concluiu-se por elevada viabilidade técnica do processo de coagulação-floculação para o lixiviado com e sem pré-tratamento, a partir da otimização das condições de contorno do processo. O pré-tratamento em RSB, quando utilizado controle de pH, demonstrou grande potencial para nitrificação/desnitrificação e oxidação de significante parcela da matéria carbonácea do lixiviado bruto. / The form of treatment and disposal still prevalent worldwide for solid waste is the landfill, a method that generates, in addition to a solid mass residual partially stabilized, liquid and gas end products. The effluent liquid, known as leachate, requires specific treatment, due to its high harmfulness to the environment, due mainly to its high concentrations of ammonia nitrogen and organic matter in high percentage, recalcitrant. This study evaluated the treatment on bench scale, via physico-chemical process, by coagulation-flocculation, of raw leachate from Central de Resíduos do Recreio landfill (operated by Companhia Riograndense de Valorização de Resíduos), devoid of any previous treatment, and biologically pretreated leachate reactors in sequential batch reactors (SBR). For the process of flocculation-coagulation were tested polyaluminum chloride (PAC), ferric chloride, ferric sulfate and tannin. Successive stages were designed for determining dosage and optimum pH adjustment for each coagulant employed and for verifying the influence of times and gradients mixtures, as well as tested in the application of polymers flocculation auxiliaries. The answers used for parametric monitoring and evaluation of efficiencies were the true color, turbidity (with and without prior filtration), COD, sludge volume and pH. The use of sequential batch reactor aimed conventional nitrification/denitrification of the high concentrations of ammonia nitrogen and eventual oxidation of carbonaceous matter. It was found that the different gradients and mixing times tested, as well as the use of auxiliary polymers, did not produce impact on the results. The inorganic coagulants showed high removal efficiencies, especially ferric chloride, which at a dose of 1102 mgFe+3/L and initial pH adjusted to 6.2, removed 98% of the true color and filtered turbidity, 63% of COD, 40% of BOD5 and 88% of unfiltered turbidity. Despite the considerable fraction of the recalcitrance of organic matter in the leachate, the SBR2 removed 40% of COD and 60% of BOD5 of the original. The coagulation-flocculation of the effluent from SBR2 required lower dosages of coagulants in relation to the similar process with raw leachate. Ferric chloride in optimum dosage of 826 mgFe+3/L and adjusting pH to 6.3, removed 95% of color, 77% of COD, 82% of BOD5, 94% of the filtered turbidity and 92% of unfiltered turbidity. It was concluded by high technical feasibility of the process of flocculation-coagulation for the leachate with and without pre-treatment, based on the optimization of the boundary conditions of the process. The pre-treatment with SBR, when pH control, demonstrated high potential for nitrification/denitrification and oxidation of a significant portion of the carbonaceous of the raw leachate.

A separação de microrganismos fotossintetizantes no tratamento de efluentes possui dois aspectos fundamentais. O primeiro refere-se à qualidade do efluente tratado e seu impacto sobre os recursos hídricos e, o segundo, refere-se ao potencial deste material como fonte de energia renovável. Diversos trabalhos tem demostrado elevada eficiência na separação de algas no tratamento de efluentes. Entretanto, quando considerado o cultivo de microalgas para utilização da biomassa como matéria prima, para produção de biocombustível por exemplo, mais estudos científicos são necessários. Entre as operações de separação sólido-líquido, normalmente empregadas no tratamento de efluentes, a flotação por ar dissolvido tem se mostrado uma tecnologia vantajosa, pois, além de ser capaz de separar partículas com diâmetro reduzido e baixa velocidade de sedimentação, também permite a obtenção de um material flotado com maior percentual de sólidos, desejável para redução dos custos de processamento da biomassa algal. O objetivo deste trabalho foi avaliar a separação de microalgas cultivadas em uma lagoa de tratamento de esgoto de alta taxa através do processo de coagulação-floculação e flotação por ar dissolvido. Como contribuição aos estudos de separação por FAD, foi avaliado a estabilidade do material flotado submetido a uma agitação mecânica, utilizando a técnica de captura e análise de imagens digitais, segundo um parâmetro chamado porcentagem de área (αa) Este parâmetro é definido como o percentual de pixels pretos em relação ao total de pixels da imagem, e demonstra a instabilidade do material flotado. Os coagulantes cloreto férrico e Tanfloc SG (Tanac®) e os floculantes sintéticos do tipo poliacrilamidas (SNF Floerger®) catiônico (FO4550SH), aniônico (FA920SH) e não iônico (FA920SH) foram investigados em diferentes dosagens e combinações. O presente estudo mostrou que a separação de algas através deste sistema é viável tecnicamente, sendo que os melhores resultados apresentaram uma remoção de turbidez de 92% para a combinação de cloreto férrico (20mg/L) + FO4550SH (2mg/L) e 97% para Tanfloc SG (20mg/L) + AN956SH (1mg/L). Em relação à estabilidade do material flotado, as amostras que continham apenas coagulantes apresentaram valores de αa entre 4,26 e 5,49, indicando uma baixa estabilidade do material flotado. Enquanto as combinações de cloreto férrico (20mg/L) + FO4550SH(0.5mg/L) e Tanfloc SG (20mg/L) +FO4550SH (1 e 2mg/L) foram as que produziram um material flotado com maior estabilidade, apresentando αa=0,35 e αa=0,40, respectivamente, demonstrando que o uso dos polímeros proporciona uma maior estabilidade do material flotado, quando este está sujeito a turbulências. / Separation of photosynthetic microorganisms in the effluent treatment has two fundamental aspects. The first refers to the quality of the treated effluent and its impact on water resources, and the second refers to the potential of this material as a source of renewable energy. Several studies show high efficiency in the separation of algae in effluent treatment. However, more scientific studies are required considering the cultivation of microalgae for the use of them as a raw material for biomass, like biofuel for instance. Among solid-liquid separation operations normally employed in effluents treatment, dissolved air flotation has been shown to be an advantageous technology in order to separate algae, because allows not only the separation of particles with reduced diameter and low sedimentation velocity, but also produces a floating material with higher percentage of solids, which is desirable for reducing the processing costs of the algal biomass. The aim of this work was to evaluate the separation of microalgae originated on a high rate pond through the coagulation, flocculation and dissolved air flotation (DAF) processes. As a contribution to the DAF separation studies, the stability of the floating material was evaluated against mechanical agitation, using the technique of digital image analysis, according to a parameter called area percentage (αa) This parameter is defined as the percentage of pixels in relation to the total pixels of the image, and demonstrates the instability of the floating material. The ferric chloride and Tanfloc SG (Tanac®) coagulants and the synthetic flocculants polyacrylamide types (SNF Floerger®) cationic (FO4550SH), anionic (FA920SH) and nonionic (FA920SH) were investigated in different concentrations and combinations. The present study showed that algae separation through this system is technically feasible. The best results showed a turbidity removal of 92% for the combination of ferric chloride (20mg/L) + FO4550SH (2mg/L) and 97% for Tanfloc SG (20mg/ L) + AN956SH (1mg/L). In relation to the stability of the floated material, the samples containing only coagulants presented values of αa between 4.26 and 5.49, indicating a low stability of the floated material. While the ferric chloride (20mg / L) + FO4550SH (0.5mg / L) and Tanfloc SG (20mg / L) + FO4550SH (1 and 2mg / L) combinations were the ones that produced a floated material with greater stability, 0.35 and α = 0.40, respectively, demonstrating that the use of the polymers provides greater stability of the floated material when it is subjected to turbulence.

Made available in DSpace on 2016-12-23T13:49:02Z (GMT). No. of bitstreams: 1 Renan Vasconcelos Santos.pdf: 2145055 bytes, checksum: 12d61fee1beb0fbd0b1b459c9f469ff6 (MD5) Previous issue date: 2013-04-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Since the dawn of civilization, man has used microbial fermentation to produce various consumer goods. The yeast Saccharomyces cerevisiae is undoubtedly the main factor in known fermentation processes, responsible for the production of bread, beer, wine, cachaça and bioethanol. S. cerevisiae was the first eukaryotic organism to have its genome sequenced and has been used for several decades as a model for eukaryotic cellular and molecular studies. The yeast cell wall is a robust structure composed of a structural internal layer of glucan and chitin, and an outer layer of mannoproteins covalently linked to the structural layer, which determine the bulk properties of the cell surface. The flocculation of yeast can be defined as a non-sexual, reversible and calcium-dependent aggregation of cells in multicellular masses, called flocs, with subsequent sedimentation from the medium in which they are suspended. It is a very complex process and depends on numerous factors such as the characteristics of the medium (pH and the presence of cations), conditions of fermentation (oxygenation, sugars, growth temperature, and the ethanol concentration) and the expression of genes of the FLO family. The process involves the interaction of specialized cell wall proteins called lectins, present only in cell flocculants, and carbohydrates (receptors) in the cell wall of neighboring cells. Flocculation properties specifically set may lead to an improvement in the processing of fermentation biotechnology products, such as food, beverages and biofuels. The group s previous data on the identity of flocculation profile between wild yeast strains isolated from different stills showed two strains with a characteristic profile of sedimentation (BT0510 BT0605), while two others (BT0505 and BT0601) showed no flocculation capacity. The objective of this study was to evaluate the relationship between the content of carbohydrates (glucose and mannose) and cell wall-related genes to the flocculation process in order to better understand the factors that cause the difference in behavior flocculant. Yeast cells were grown in YEPD medium and incubated at 28 ° C and 150 rpm agitation. The cell wall was extracted by a combination of sonication, vigorous agitation with glass beads and boiling in detergent solution. After extensive washing with ultrapure water, the pellet containing the cell wall was incubated at 80 ° C to complete drying and determination of dry weight. Then the samples were subjected to hydrolysis with sulfuric acid, precipitation of sulphate ions by adding Ba (OH) 2, and concentration in vacuum. The liberated monosaccharides were analyzed by HPLC on a column of REZEX-RHM, isocratic elution with ultrapure water, differential refraction detector at 60 ° C. The expression levels of FLO genes and genes related to cell wall between a flocculent strain and a non-flocculent were compared using Real Time PCR. No significant difference was found between the levels of glucose and mannose in flocculent and non-flocculent strains, which suggests that the profile of flocculation is not directly related to the concentration of cell wall carbohydrates. Analysis of relative gene expression showed a significant increase in the FLO gene family (FLO1, FLO8 and FLO10) in flocculant strain, confirming expectations. A large increase of 27 times was noted in CWP1 gene, confirming studies suggesting a major importance of this gene for the cell wall and in the flocculation process. There was also an increase in other genes related to the cell wall. Studies of cell wall proteomics, and mass spectrometry analysis may help elucidate the results, and contribute to a better understanding of flocculation in fermentation processes / Desde os primórdios da civilização, o homem utiliza as fermentações microbianas para a produção de diversos bens de consumo. A levedura Saccharomyces cerevisiae é, sem dúvida, o maior expoente dos processos fermentativos conhecidos, responsável pela fabricação do pão, da cerveja, do vinho cachaça e do bioetanol. S. cerevisiae foi o primeiro organismo eucarionte a ter seu genoma sequenciado e vem sendo utilizada há várias décadas como um modelo eucarionte para estudos celulares e moleculares. A parede celular de levedura é uma robusta estrutura composta por uma camada estrutural interna de glucanos e quitina, e uma camada externa de manoproteínas covalentemente ligadas à camada estrutural, que determinam a maior parte das propriedades de superfície da célula. A floculação de levedura pode ser definida como um processo não sexual, reversível e cálcio-dependente de agregação de células em massas multicelulares, chamadas flocos, com a subsequente sedimentação a partir do meio em que elas estão suspensas. É um processo muito complexo e depende de numerosos fatores, tais como as características do meio (pH e a presença de cátions), as condições de fermentação (oxigenação, os açúcares, a temperatura de crescimento, a concentração de etanol) e a expressão dos genes da família FLO. O processo envolve a interação de proteínas especializadas da parede celular denominadas lectinas, presentes apenas em células floculantes, e carboidratos (receptores) na parede celular das células vizinhas. Propriedades de floculação especificamente ajustadas poderia levar a uma melhoria no processamento de produtos biotecnológicos de fermentação, tais como alimentos, bebidas e biocombustíveis. Dados anteriores do grupo sobre a identificação do perfil de floculação entre cepas selvagens de levedura isoladas de diferentes alambiques mostraram duas cepas com um perfil característico de sedimentação (BT0510 e BT0605), enquanto outras duas (BT0505 e BT0601) sem capacidade de floculação. Assim, o objetivo deste trabalho foi avaliar a relação entre o conteúdo de carboidratos (glicose e manose) da parede celular e de genes relacionados à parede com o processo da floculação, a fim de melhor entender os fatores que causam a diferença no comportamento floculante. As células de levedura foram cultivadas em meio YEPD, incubadas a 28 ºC e 150 rpm de agitação. A parede celular foi extraída por combinação de sonicação, agitação vigorosa com pérolas de vidro e de ebulição em solução detergente. Após lavagem extensiva com água ultra pura, o pellet contendo a parede celular foi incubado a 80 ºC para secagem completa e determinação do peso seco. Em seguida, as amostras foram submetidas a uma hidrólise com ácido sulfúrico, precipitação de íons sulfato por adição de Ba(OH)2, e concentração a vácuo. Os monossacarídeos liberados foram analisados por HPLC na coluna REZEX-RHM, eluição isocrática com água ultra pura, detector de refração diferencial a 60 ºC. Por PCR em Tempo Real foram comparados os níveis de expressão dos genes FLO e de genes relacionados à parede celular entre uma cepa floculante e outra não-floculante. Não foi encontrada diferença significativa entre o teor de glicose e manose nas cepas floculantes e não floculantes, o que sugere que o perfil de floculação não está diretamente relacionado com a concentração de carboidratos de parede celular. A análise da expressão gênica relativa mostrou um aumento significativo dos genes da família FLO (FLO1, FLO8 e FLO10) na cepa floculante, confirmando as expectativas. Um grande aumento, de 27 vezes, foi observado no gene CWP1, corroborando com estudos que sugerem uma grande importância deste gene para a integridade da parede celular e para o processo de floculação. Também houve aumento de outros genes relacionados à parede celular. Estudos de proteômica da parede celular, além de análise em espectrometria de massas poderiam ajudar a elucidar os resultados encontrados, e contribuir para o melhor entendimento da floculação nos processos fermentativos