1000 resultados para Digestão de águas residuais


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The use of geophysical methods in the analysis and mapping of likely contamination plumes has shown a huge value in the development of researches related to environmental issues. Among the main geophysical methods applied to this purpose, the geoelectrical methods stand out, being based on the use of electric and electromagnetic fields. The electromagnetic method (EM) uses physical environment responses created by electromagnetic field propagation, consisting of an alternated electric output and a magnetization force, used to obtain the electric conductivity (σ) of the subsurface materials. It has a broad application in the mineral exploration and prospection, and its use has been also efficient in environmental researches. By the electromagnetic method, this work examined and mapped possible contaminations created by cemetery leachate in the Saudade's Cemetery, located in the city of Monte Alto, Sao Paulo, where sedimentary rocks of the Bauru Group are exposed. Cemetery leachate is a putrefactive liquid, generated from the decomposition of organic matter, which contains substances that can contaminate soil and groundwater. Results achieved in this work show that the use of the electromagnetic method is an important indirect tool in the investigation of environmental contaminations in areas with highly contrasting physical properties

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This study used a multi-analytical approach based on traditional microbiological methods for cultivation and isolation of heterotrophic bacteria in the laboratory associated with the molecular identification of the isolates and physicochemical analysis of environmental samples. The model chosen for data integration was supported by knowledge from computational neuroscience, and composed by three modules: (i) microbiological parameters, contemplating taxonomic data obtained from the partial sequencing of the 16S rRNA gene from 80 colonies of heterotrophic bacteria isolated by plating method in PCA media. For bacterial colonies isolation were used water samples from Atibaia and Jaguarí rivers collected at the site of water captation for use in effluent treatment, upstream from the entrance of treated effluent from the Paulínia refinery (REPLAN/Petrobras) located in the Paulínia-SP municipality, from the output of the biological treatment plant with stabilization pond and from the raw refinery wastewater; (ii) chemical parameters, ending measures of dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, acidity CaCO3, alkalinity, ammonia, nitrite, nitrate, dissolved ions, sulfides, oils and greases; and (iii) physical parameters, comprising the pH determination, conductivity, temperature, transparency, settleable solids, suspended and soluble solids, volatile material, remaining fixing material (RFM), apparent color and turbidity. The results revealed interesting theoretical relationships involving two families of bacteria (Carnobacteriaceae and Aeromonadaceae). Carnobacteriaceae revealed positive theoretical relationships with COD, BOD, nitrate, chloride, temperature, conductivity and apparent color and negative theoretical relationships with the OD. Positive theoretical relationships were shown between Aeromonadaceae and OD and nitrate, while this bacterial family showed negative theoretical...

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Com o grande crescimento da população e consequentemente o aumento significativo do consumo de produtos de origem industrial, quantidades enormes de efluentes são geradas, e muitas vezes descartadas de forma imprópria. Esses resíduos industriais comumente são eliminados em mananciais hídricos, afetando lençóis freáticos, córregos, rios e oceanos. Uma das maiores evidências da poluição da água é a alteração de sua cor original. Despejo de efluentes têxteis, por exemplo, alem de alterar drasticamente a cor dos mananciais, geram produtos e subprodutos tóxicos, nocivos tanto para a flora como para a fauna aquática. Essas substâncias possuem alta persistência em meio aquático devido a sua natureza química, conferindo a estes efluentes um lento processo de biodegradação e podendo ter efeito bioacumulativo na cadeia alimentar. Assim veem sendo desenvolvidas diversas maneiras de se controlar a quantidade e a qualidade de efluentes industriais, dentre eles os de corantes têxteis. As técnicas mais utilizadas são a cloração, filtração, tratamentos floculantes e adsorção por Carvão Ativados. Porem, muitas vezes esses processos possuem desvantagens, como, por exemplo, o alto custo e alterações drásticas no pH. Assim tratamentos alternativos, como o uso de Moringa oleifera, veem sendo muito estudados. Este trabalho visou avaliar o potencial do uso das sementes de Moringa oleifera como adsorvente na remoção de corantes têxteis em meio aquoso. Para isso foi analisado a remoção do corante Direct Violet 51, utilizando pó das sementes. Foram realizados testes com diferentes tempos de contato nos valores de pH 2,5, 4,5 e 6,5. Posteriormente novos testes foram realizados, utilizando o sobrenadante e a biomassa das sementes, ambos na forma livre e imobilizada em alginato de calcio, bem como reutilização destes. Através da analise das amostras, notou-se que o processo de coagulação/floculação sobressaiu-se em...

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This study used a multi-analytical approach based on traditional microbiological methods for cultivation and isolation of heterotrophic bacteria in the laboratory associated with the molecular identification of the isolates and physicochemical analysis of environmental samples. The model chosen for data integration was supported by knowledge from computational neuroscience, and composed by three modules: (i) microbiological parameters, contemplating taxonomic data obtained from the partial sequencing of the 16S rRNA gene from 80 colonies of heterotrophic bacteria isolated by plating method in PCA media. For bacterial colonies isolation were used water samples from Atibaia and Jaguarí rivers collected at the site of water captation for use in effluent treatment, upstream from the entrance of treated effluent from the Paulínia refinery (REPLAN/Petrobras) located in the Paulínia-SP municipality, from the output of the biological treatment plant with stabilization pond and from the raw refinery wastewater; (ii) chemical parameters, ending measures of dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, acidity CaCO3, alkalinity, ammonia, nitrite, nitrate, dissolved ions, sulfides, oils and greases; and (iii) physical parameters, comprising the pH determination, conductivity, temperature, transparency, settleable solids, suspended and soluble solids, volatile material, remaining fixing material (RFM), apparent color and turbidity. The results revealed interesting theoretical relationships involving two families of bacteria (Carnobacteriaceae and Aeromonadaceae). Carnobacteriaceae revealed positive theoretical relationships with COD, BOD, nitrate, chloride, temperature, conductivity and apparent color and negative theoretical relationships with the OD. Positive theoretical relationships were shown between Aeromonadaceae and OD and nitrate, while this bacterial family showed negative theoretical...

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Com o grande crescimento da população e consequentemente o aumento significativo do consumo de produtos de origem industrial, quantidades enormes de efluentes são geradas, e muitas vezes descartadas de forma imprópria. Esses resíduos industriais comumente são eliminados em mananciais hídricos, afetando lençóis freáticos, córregos, rios e oceanos. Uma das maiores evidências da poluição da água é a alteração de sua cor original. Despejo de efluentes têxteis, por exemplo, alem de alterar drasticamente a cor dos mananciais, geram produtos e subprodutos tóxicos, nocivos tanto para a flora como para a fauna aquática. Essas substâncias possuem alta persistência em meio aquático devido a sua natureza química, conferindo a estes efluentes um lento processo de biodegradação e podendo ter efeito bioacumulativo na cadeia alimentar. Assim veem sendo desenvolvidas diversas maneiras de se controlar a quantidade e a qualidade de efluentes industriais, dentre eles os de corantes têxteis. As técnicas mais utilizadas são a cloração, filtração, tratamentos floculantes e adsorção por Carvão Ativados. Porem, muitas vezes esses processos possuem desvantagens, como, por exemplo, o alto custo e alterações drásticas no pH. Assim tratamentos alternativos, como o uso de Moringa oleifera, veem sendo muito estudados. Este trabalho visou avaliar o potencial do uso das sementes de Moringa oleifera como adsorvente na remoção de corantes têxteis em meio aquoso. Para isso foi analisado a remoção do corante Direct Violet 51, utilizando pó das sementes. Foram realizados testes com diferentes tempos de contato nos valores de pH 2,5, 4,5 e 6,5. Posteriormente novos testes foram realizados, utilizando o sobrenadante e a biomassa das sementes, ambos na forma livre e imobilizada em alginato de calcio, bem como reutilização destes. Através da analise das amostras, notou-se que o processo de coagulação/floculação sobressaiu-se em...

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A qualidade ambiental das praias tem vindo a adquirir uma importância crescente entre os critérios de escolha de destino turístico. Apesar de, nos últimos anos, a legislação ter evoluído no sentido do ordenamento da zona costeira e do tratamento de águas residuais, a qualidade da água balnear é o único indicador da qualidade relacionado com a saúde pública que pode permitir aos utentes uma escolha orientada. Portugal apresenta-se na comunidade internacional como o primeiro país com um programa de monitorização de qualidade de areias, desenvolvendo ainda atividades de investigação a vários níveis que o permitam melhorar. Outros países avaliam técnicas de determinação de fontes de contaminação de águas de recreio, incluindo areias adjacentes e pesquisa de agentes etiológicos não monitorizados pelas legislações em vigor. Assim, há que concertar esforços no sentido de se encontrarem formas de monitorizar o risco para a saúde em tempo tão útil quanto possível, bem como reavaliar indicadores e seus limites de aceitação, mantendo a liderança desta atividade. Na sequência do Microareias 2012, em que foi feita uma reavaliação dos parâmetros interessantes para este tipo de análise, e numa fase em que internacionalmente se programam atividades técnico-científicas concertadas, foi montado um esquema de avaliação inter-laboratorial com laboratórios pioneiros nacionais. Em 2016, será apresentado o programa já implementado aos laboratórios atualmente participantes, aberto a laboratórios candidatos e profissionais interessados onde será feita uma atualização de conhecimentos e situação internacional.

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Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

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In this work, the treatment of wastewater from the textile industry, containing dyes as Yellow Novacron (YN), Red Remazol BR (RRB) and Blue Novacron CD (NB), and also, the treatment of wastewater from petrochemical industry (produced water) were investigated by anodic oxidation (OA) with platinum anodes supported on titanium (Ti/Pt) and boron-doped diamond (DDB). Definitely, one of the main parameters of this kind of treatment is the type of electrocatalytic material used, since the mechanisms and products of some anodic reactions depend on it. The OA of synthetic effluents containing with RRB, NB and YN were investigated in order to find the best conditions for the removal of color and organic content of the dye. According to the experimental results, the process of OA is suitable for decolorization of wastewaters containing these textile dyes due to electrocatalytic properties of DDB and Pt anodes. Removal of the organic load was more efficient at DDB, in all cases; where the dyes were degraded to aliphatic carboxylic acids at the end of the electrolysis. Energy requirements for the removal of color during OA of solutions of RRB, NB and YN depends mainly on the operating conditions, for example, RRB passes of 3.30 kWh m-3 at 20 mA cm-2 for 4.28 kWh m-3 at 60 mA cm-2 (pH = 1); 15.23 kWh m-3 at 20 mA cm-2 to 24.75 kWh m-3 at 60 mA cm-2 (pH 4.5); 10.80 kWh m-3 at 20 mA cm-2 to 31.5 kWh m-3 at 60 mA cm-2 (pH = 8) (estimated data for volume of treated effluent). On the other hand, in the study of OA of produced water effluent generated by petrochemical industry, galvanostatic electrolysis using DDB led to the complete removal of COD (98%), due to large amounts of hydroxyl radicals and peroxodisulphates generated from the oxidation of water and sulfates in solution, respectively. Thus, the rate of COD removal increases with increasing applied current density (15-60 mAcm-2 ). Moreover, at Pt electrode, approximately 50% removal of the organic load was achieved by applying from 15 to 30 mAcm-2 while 80% of COD removal was achieved for 60 mAcm-2 . Thus, the results obtained in the application of this technology were satisfactory depending on the electrocatalytic materials and operating conditions used for removal of organic load (petrochemical and textile effluents) as well as for the removal of color (in the case of textile effluents). Therefore, the applicability of electrochemical treatment can be considered as a new alternative like pretreatment or treatment of effluents derived from textiles and petrochemical industries.

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Textile industry has been a cause of environmental pollution, mainly due to the generation of large volumes of waste containing high organic loading and intense color. In this context, this study evaluated the electrochemical degradation of synthetic effluents from textile industry containing Methylene Blue (AM) dye, using Ti/IrO2-Ta2O5 and Ti/Pt anodes, by direct and indirect (active chlorine) electrooxidation. We evaluated the influence of applied current density (20, 40 and 60 mA/cm2 ), and the presence of different concentrations of electrolyte (NaCl and Na2SO4), as well as the neutral and alkaline pH media. The electrochemical treatment was conducted in a continuous flow reactor, in which the electrolysis time of the AM 100 ppm was 6 hours. The performance of electrochemical process was evaluated by UV-vis spectrophotometry, chemical oxygen demand (COD) and total organic carbon (TOC). The results showed that with increasing current density, it was possible to obtain 100 % of color removal at Ti/IrO2-Ta2O5 and Ti/Pt electrodes. Regarding the color removal efficiency, increasing the concentration of electrolyte promotes a higher percentage of removal using 0,02 M Na2SO4 and 0,017 M NaCl. Concerning to the aqueous medium, the best color removal results were obtained in alkaline medium using Ti/Pt. In terms of organic matter, 86 % was achieved in neutral pH medium for Ti/Pt; while a 30 % in an alkaline medium. To understand the electrochemical behavior due to the oxygen evolution reaction, polarization curves were registered, determining that the presence of NaCl in the solution favored the production of active chlorine species. The best results in energy consumption and cost were obtained by applying lower current density (20 mA/cm2 ) in 6 hours of electrolysis.

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The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.

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The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.

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The monoaromatic compounds are toxic substances present in petroleum derivades and used broadly in the chemical and petrochemical industries. Those compounds are continuously released into the environment, contaminating the soil and water sources, leading to the possible unfeasibility of those hydrous resources due to their highly carcinogenic and mutagenic potentiality, since even in low concentrations, the BTEX may cause serious health issues. Therefore, it is extremely important to develop and search for new methodologies that assist and enable the treatment of BTEX-contaminated matrix. The bioremediation consists on the utilization of microbial groups capable of degrading hydrocarbons, promoting mineralization, or in other words, the permanent destruction of residues, eliminating the risks of future contaminations. This work investigated the biodegradation kinetics of water-soluble monoaromatic compounds (benzene, toluene and ethylbenzene), based on the evaluation of its consummation by the Pseudomonas aeruginosa bacteria, for concentrations varying from 40 to 200 mg/L. To do so, the performances of Monod kinetic model for microbial growth were evaluated and the material balance equations for a batch operation were discretized and numerically solved by the fourth order Runge-Kutta method. The kinetic parameters obtained using the method of least squares as statistical criteria were coherent when compared to those obtained from the literature. They also showed that, the microorganism has greater affinity for ethylbenzene. That way, it was possible to observe that Monod model can predict the experimental data for the individual biodegradation of the BTEX substrates and it can be applied to the optimization of the biodegradation processes of toxic compounds for different types of bioreactors and for different operational conditions.

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The monoaromatic compounds are toxic substances present in petroleum derivades and used broadly in the chemical and petrochemical industries. Those compounds are continuously released into the environment, contaminating the soil and water sources, leading to the possible unfeasibility of those hydrous resources due to their highly carcinogenic and mutagenic potentiality, since even in low concentrations, the BTEX may cause serious health issues. Therefore, it is extremely important to develop and search for new methodologies that assist and enable the treatment of BTEX-contaminated matrix. The bioremediation consists on the utilization of microbial groups capable of degrading hydrocarbons, promoting mineralization, or in other words, the permanent destruction of residues, eliminating the risks of future contaminations. This work investigated the biodegradation kinetics of water-soluble monoaromatic compounds (benzene, toluene and ethylbenzene), based on the evaluation of its consummation by the Pseudomonas aeruginosa bacteria, for concentrations varying from 40 to 200 mg/L. To do so, the performances of Monod kinetic model for microbial growth were evaluated and the material balance equations for a batch operation were discretized and numerically solved by the fourth order Runge-Kutta method. The kinetic parameters obtained using the method of least squares as statistical criteria were coherent when compared to those obtained from the literature. They also showed that, the microorganism has greater affinity for ethylbenzene. That way, it was possible to observe that Monod model can predict the experimental data for the individual biodegradation of the BTEX substrates and it can be applied to the optimization of the biodegradation processes of toxic compounds for different types of bioreactors and for different operational conditions.

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Oil exploration is one of the most important industrial activities of modern society. Despite its derivatives present numerous applications in industrial processes, there are many undesirable by-products during this process, one of them is water separated from oil, called water production, it is constituted by pollutants difficult to degrade. In addition, the high volume of generated water makes its treatment a major problem for oil industries. Among the major contaminants of such effluents are phenol and its derivatives, substances of difficult natural degradation, which due their toxicity must be removed by a treatment process before its final disposal. In order to facilitate the removal of phenol in wastedwater from oil industry, it was developed an extraction system by ionic flocculation with surfactant. The ionic flocculation relies on the reaction of carboxylate surfactant and calcium íons, yielding in an insoluble surfactant that under stirring, aggregates forming floc capable of attracting the organic matter by adsorption. In this work was used base soap as ionic surfactant in the flocculation process and evaluated phenol removal efficiency in relation to the following parameters: surfactant concentration, phenol, calcium and electrolytes, stirring speed, contact time, temperature and pH. The flocculation of the surfactant occurred in the effluent (initial phenol concentration = 100 ppm) reaching 65% of phenol removal to concentrations of 1300 ppm and calcium of 1000 ppm, respectively, at T = 35 °C, pH = 9.7, stirring rate = 100 rpm and contact time of 5 minutes. The permanence of the flocs in an aqueous medium promotes desorption of the phenol from the flake surface to the solution, reaching 90% of desorption at a time of 150 minutes, and the study of desorption kinetics showed that Lagergren model of pseudo-first order was adequate to describe the phenol desorption. These results shows that the process may configure a new alternative of treatment in regard the removal of phenol of aqueous effluent of oil industry.