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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Emprego dos processos de eletrofloculação e osmose inversa no tratamento de águas oleosas / The use of electroflocculation and reverse osmosis in the treatment of oily wastewater

Leonardo Firmino da Silva 26 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A descarga desenfreada de águas residuais no meio ambiente, ao longo dos últimos anos, vem acelerando o processo de contaminação e degradação dos corpos hídricos no mundo. Tais rejeitos apresentam elevada carga de contaminantes e de concentração de matéria orgânica o que leva a mortandade das espécies pela concorrência ao oxigênio e, em casos extremos, a aceleração dos processos de eutrofização. Pensando nisso, o presente trabalho estudou um sistema híbrido, em batelada, de tratamento de águas oleosas simuladas em laboratório pela adição de um determinado óleo lubrificante em uma solução aquosa de agentes emulsificantes e eletrólito suporte. O sistema de tratamento foi composto de duas etapas, onde na primeira avaliou-se o uso da técnica da eletrofloculação, responsável por quebrar a estabilidade das emulsões óleo/água e de uma segunda que avaliou o uso de processos de separação com membranas visando à remoção do metal adicionado ao efluente na etapa anterior. O sistema de eletrofloculação foi avaliado em relação ao uso de eletrodos de alumínio e ferro com correntes elétricas de 1A, 2A e 3A, nos modos contínuo e alternado. Os resultados apontaram um maior consumo evidente de massa de eletrodos quando do uso da corrente contínua, 4,0337g 0,0132 para o alumínio e 3,8260g 0,0181 para o ferro ao passo que o consumo foi de 2,1400g 0,0099 para o alumínio e 2,4121g 0,0127 para o ferro quando do o uso da corrente alternada. Foram alcançadas remoções máximas de 98 % 0 da DQO, 99,77 % 0,27 de remoção da cor e 100 % 0 de remoção da turbidez para o uso de corrente alternada e eletrodos de alumínio enquanto se alcançaram remoções máximas 96 % 1 da DQO, 99,46 % 0,82 de remoção da cor e também 100 % 0 de remoção da turbidez no uso de eletrodos de ferro. Na segunda etapa do estudo, a osmose inversa, o sistema utilizado atingiu rejeições de 99,53 % 0,12; 99,56 % 0,13 e de 98,87 % 0,36, para pressões respectivas de 10, 20 e 30 bar. Além disso, foram obtidos fluxos crescentes de permeado 10,87 L/h.m2 0,25; 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 com o também aumento da pressão. Ao final do estudo alcançou-se um efluente final com baixa carga orgânica e de metais, estando o mesmo apto ao lançamento nos corpos receptores. Entretanto, mecanismos de controle, sobretudo de pH devem ser incluídos no projeto desses sistemas uma vez que esse parâmetro sofre alterações ao longo do processo / The uncontrolled discharge of wastewater into the environment over the last years has accelerated the process of contamination and degradation of water bodies in the world. These wastes contain high amounts of contaminants and concentration of organic matter which leads to the death of several species due to lack of oxygen and, in extreme cases, acceleration of eutrophication processes. In the specific case of oily wastewater, the use of techniques such as chemical coagulation, dissolved air injection, membranes, biochemical and electrochemical processes are described. However some of these processes have limitations which range from the concentration of the contaminant in the effluent, limitations in the operating conditions and even cost constraints. With this in mind, this paper has studied a hybrid system, batch process, in the treatment of oily waters simulated in the laboratory by adding a specific lubricating oil in an aqueous solution with emulsifiers and supporting electrolyte. The treatment system was consisted of two stages, which in the first was evaluated the use of the technique of electrocoagulation, which was responsible by the breaking stability of oil/water emulsions and a second stage which evaluated the use of membrane separation processes in order to remove the metal added to the effluent in the previous stage. The electrofloculation system was evaluated in relation to the use of iron and aluminum electrodes with electrical currents of 1A, 2A and 3A, in the continuous and alternate modes. The results showed a higher apparent mass consumption of electrodes when using direct current, 4,0337 g 0,0132 for aluminum and 3,8260 g 0,0181 for iron while consumption was 2,1400 g 0,0099 for aluminum, and 2,4121 0,0127 g for the iron when the use of alternating current. Removals were reached maximum 98 % 0 COD, 99,77 % 0,27 color removal and 100 % 0 turbidity removal for use alternating current and aluminum electrodes while were reached maximum 96 % 1 of COD, 99,46 % 0, 82 color removal and also 100% 0 to remove the turbidity in the use of iron electrodes. In the second study phase, reverse osmosis, the system used has reached rejections 99,53 % 0,12, 99,56 % 0,13 and 98,87 % 0,36, corresponding to pressures of 10 , 20 and 30 bar Moreover, increasing flows were obtained permeate 10,87 L/h.m2 0,25, 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 also with the increased pressure. At the end of the study was reached final effluent with low organic load and metals, it being able to release the bodies receptors. However, control mechanisms, particularly pH should be included in the design of such systems since this parameter changes over the process
12

Estudo de remediação de solo contaminado por borra oleosa ácida utilizando a técnica de encapsulamento / Study for repairing soil contaminated with acidic oily sludge using the encapsulation technique

Jiménez Rojas, José Waldomiro January 2007 (has links)
Este trabalho tem como objetivo aplicar a técnica de encapsulamento, conhecida também como solidificação/estabilização, em um solo contaminado com crescentes quantidades do resíduo industrial borra oleosa ácida, utilizando como agente encapsulante o cimento Portland CP-V ARI. O programa experimental consistiu na realização de estudos pré e pós-tratamento, analisando fisicamente o solo através de ensaios de caracterização geotécnica, compactação, resistência à compressão simples, durabilidade e condutividade hidráulica. Quimicamente foram realizados ensaios de lixiviação em coluna e análises químicas e físico-químicas do lixiviado. Devido às elevadas temperaturas detectadas no momento das misturas de solo/cimento e borra oleosa ácida, foram realizados ensaios para o monitoramento da temperatura e o tempo de hidratação do cimento. Os resultados apontam que quanto maior a quantidade de borra oleosa ácida presente no solo tratado, maior é a temperatura de hidratação do cimento e mais rápido atinge o pico máximo, resultando em menor resistência à compressão simples e maior perda de massa. Em amostras sem cimento, a condutividade hidráulica diminui com o aumento de borra oleosa ácida, quando adicionado cimento a condutividade hidráulica inicialmente diminui com o acréscimo de borra oleosa ácida, mas volta a aumentar com quantidades maiores de contaminante. A técnica de encapsulamento mostrou-se eficiente quanto à redução dos metais pesados, devido, principalmente, ao aumento do pH e a precipitação de tais elementos. Porém não se mostrou eficiente quanto ao sulfato, condutividade elétrica e demanda química de oxigênio. / The objective of this study is applying the encapsulation technique, also known as solidification/stabilization, in soil contaminated with increasing amounts of acidic oily sludge industrial residues, using Portland cement CP-V ARI as the encapsulating agent. The experimental program consisted of studies pre and post-treatment, in which the soil was physically analyzed through geotechnical characterization testings, compactation, unconfined compressive strength, duration and hydraulic conductivity tests. In chemical terms, column leach testings were conducted, along with chemical and physical-chemical analyses of the leachete. Due to the high temperatures detected upon mixing soil/cement and the acidic oily sludge, tests were conducted to monitor the temperature and the hydratation rate of the cement. The results show that the greater the amount of acidic oily sludge in the treated soil, the higher the temperature necessary to hydrate the cement and the faster it reaches the maximum peak, which results in less unconfined compressive strength and greater mass loss. In samples without cement, the hydraulic conductivity reduced upon increasing the amount of acidic oily sludge. When cement is added, the hydraulic conductivity initially decreases with the acidic oily sludge, but it increases again with greater amounts of the substance. The encapsulation technique proved to be efficient in the reduction of heavy metals, due mainly to the pH increase and the precipitation of such components. However, the technique did not prove to be efficient in relation to sulphate, and to the electrical conductivity and the chemical oxygen demand.
13

Estudo de remediação de solo contaminado por borra oleosa ácida utilizando a técnica de encapsulamento / Study for repairing soil contaminated with acidic oily sludge using the encapsulation technique

Jiménez Rojas, José Waldomiro January 2007 (has links)
Este trabalho tem como objetivo aplicar a técnica de encapsulamento, conhecida também como solidificação/estabilização, em um solo contaminado com crescentes quantidades do resíduo industrial borra oleosa ácida, utilizando como agente encapsulante o cimento Portland CP-V ARI. O programa experimental consistiu na realização de estudos pré e pós-tratamento, analisando fisicamente o solo através de ensaios de caracterização geotécnica, compactação, resistência à compressão simples, durabilidade e condutividade hidráulica. Quimicamente foram realizados ensaios de lixiviação em coluna e análises químicas e físico-químicas do lixiviado. Devido às elevadas temperaturas detectadas no momento das misturas de solo/cimento e borra oleosa ácida, foram realizados ensaios para o monitoramento da temperatura e o tempo de hidratação do cimento. Os resultados apontam que quanto maior a quantidade de borra oleosa ácida presente no solo tratado, maior é a temperatura de hidratação do cimento e mais rápido atinge o pico máximo, resultando em menor resistência à compressão simples e maior perda de massa. Em amostras sem cimento, a condutividade hidráulica diminui com o aumento de borra oleosa ácida, quando adicionado cimento a condutividade hidráulica inicialmente diminui com o acréscimo de borra oleosa ácida, mas volta a aumentar com quantidades maiores de contaminante. A técnica de encapsulamento mostrou-se eficiente quanto à redução dos metais pesados, devido, principalmente, ao aumento do pH e a precipitação de tais elementos. Porém não se mostrou eficiente quanto ao sulfato, condutividade elétrica e demanda química de oxigênio. / The objective of this study is applying the encapsulation technique, also known as solidification/stabilization, in soil contaminated with increasing amounts of acidic oily sludge industrial residues, using Portland cement CP-V ARI as the encapsulating agent. The experimental program consisted of studies pre and post-treatment, in which the soil was physically analyzed through geotechnical characterization testings, compactation, unconfined compressive strength, duration and hydraulic conductivity tests. In chemical terms, column leach testings were conducted, along with chemical and physical-chemical analyses of the leachete. Due to the high temperatures detected upon mixing soil/cement and the acidic oily sludge, tests were conducted to monitor the temperature and the hydratation rate of the cement. The results show that the greater the amount of acidic oily sludge in the treated soil, the higher the temperature necessary to hydrate the cement and the faster it reaches the maximum peak, which results in less unconfined compressive strength and greater mass loss. In samples without cement, the hydraulic conductivity reduced upon increasing the amount of acidic oily sludge. When cement is added, the hydraulic conductivity initially decreases with the acidic oily sludge, but it increases again with greater amounts of the substance. The encapsulation technique proved to be efficient in the reduction of heavy metals, due mainly to the pH increase and the precipitation of such components. However, the technique did not prove to be efficient in relation to sulphate, and to the electrical conductivity and the chemical oxygen demand.
14

Desenvolvimento e avaliação de eficácia de formulações fotoprotetoras para a pele oleosa contendo extrato de Anacardium occidentale / Development and efficacy evaluation of photoprotective formulations for oily skin containing extract of Anacardium occidentale

Daiane Garcia Mercurio 05 April 2012 (has links)
A pele oleosa e acneica apresenta características diferenciadas e demanda o uso de produtos cosméticos adequados e que proporcionem benefícios específicos a esse tipo de pele. Nesse contexto, o extrato de caju (Anacardium occidentale), devido a sua rica composição, apresenta propriedades que podem promover benefícios para os cuidados da pele oleosa. Assim, o objetivo desse projeto foi desenvolver formulações fotoprotetoras estáveis contendo extrato glicólico de Anacardium occidentale, bem como a avaliação da eficácia clínica destas formulações para a melhoria das condições da pele oleosa. Para tal, foram desenvolvidas formulações fotoprotetoras com matérias primas compatíveis com a pele oleosa, as quais foram submetidas aos testes preliminares de estabilidade e, a mais estável foi selecionada para a avaliação da atividade fotoprotetora in vitro, a avaliação sensorial e avaliação de eficácia clínica dos efeitos imediatos (duas e quatro horas após aplicação) e em longo prazo (após 28 dias de aplicação diária das formulações). Foi realizada também a determinação do espectro de absorção do extrato de caju, avaliação da atividade antioxidante in vitro, e determinação do teor de polifenóis. Preliminar ao estudo de eficácia, foi realizado o estudo de caracterização e classificação dos tipos de pele por score dermatológico e com as técnicas avançadas de biofísica e análise de imagem. Dentre as formulações desenvolvidas, a que continha \"Sodium Polyacrylate (and) Dimethicone (and) Cyclopentasiloxane (and) Trideceth-6 (and) PEG/PPG 18/18 Dimethicone e Acrylates/C10-30 Alkyl Acrylate Crosspolymer como agentes emulsificantes e espessantes e \"Octyl Stearate\" como emoliente e agente dispersante do filtro físico, e \"Sílica\" e \"Polymethyil Methacrylate\" como pós modificadores de sensorial (F15), foi adicionada de 3,5% de extrato glicólico de caju (F15C) e foi estável nos testes preliminares de estabilidade. Na avaliação da atividade fotoprotetora in vitro a formulação apresentou FPS 50, Boost Factor \"Bom\" e comprimento de onda crítico acima de 370 nm. O extrato glicólico de caju apresentou atividade antioxidante dose dependente. A caracterização do tipo de pele demonstrou que o grupo com pele oleosa apresentou maior perda transepidérmica de água, maior aspereza e oleosidade. Além disso, a análise computacional de imagens mostrou diferenças quanto à secreção sebácea, poros e comedões nas regiões malar, queixo e nariz. Nos estudos de avaliação de eficácia, a formulação F15C apresentou melhores notas nos parâmetros relacionados à sensação ao toque, oleosidade, resíduo de brilho e suavidade, bem como na intenção de compra. Na avaliação dos efeitos imediatos, não foram obtidos efeitos no conteúdo aquoso do estrato córneo, perda transepidérmica de água e nos parâmetros do microrrelevo. A formulação F15C apresentou retenção do conteúdo de sebo, comparada à formulação veículo após duas e quatro horas de aplicação da formulação. Na avaliação dos efeitos das formulações a longo prazo, a formulação proporcionou redução do número de poros no queixo e não proporcionou aumento de comedões e alterações significativas nos parâmetros: conteúdo aquoso do estrato córneo, perda transepidermica de água, parâmetros do microrrelevo, secreção sebácea, contagem de glândulas sebáceas ativas. A formulação desenvolvida apresenta-se como um produto inovador e diferenciado, com eficácia e sensorial agradável e compatível ao uso na pele oleosa. Além disso, o extrato de caju melhorou ainda mais o sensorial da formulação e mostrou eficácia pré clínica com, potencial antioxidante, e eficácia clínica no controle da oleosidade e melhoria das condições da pele oleosa. / Oily skin has different characteristics and demands the use of cosmetic products that provide adequate and specific benefits to this skin type. In this context, the cashew extract (Anacardium occidentale), due to its rich composition, has properties that can provide benefits for oily skin care. The objective of this project was to develop stable photoprotective formulations containing glycolic extract of Anacardium occidentale, as well as to evaluate the clinical efficacy of these formulations for the improvement of oily skin conditions. For this purpose, the photoprotective formulations were developed with raw materials compatible with oily skin, which were submitted to preliminary tests of stability, and the most stable was selected to evaluate the sunscreen activity in vitro, sensory evaluation and assessment of clinical efficacy in terms of immediate (two and four hours after application) and long term effects (after 28 days of daily application of the formulations). It was also determined the spectrum of absorption of the cashew extract, antioxidant activity evaluation in vitro, and determination of polyphenols. Before de efficacy evaluation, studies were conducted to characterize and classify skin types using dermatological score and advanced biophysical techniques and skin imaging analysis. Among the formulations developed, the one which contained \"Sodium Polyacrylate (and) Dimethicone (and) Cyclopentasiloxane (and) Trideceth-6 (and) PEG/PPG 18/18 Dimethicone e Acrylates/C10-30 Alkyl Acrylate Crosspolymer as emulsifiers and thickner agents and \"Octyl Stearate\" as an emollient and dispersing agent of the inorganic filter and \"Silica\" and \'Polymethyl Methacrylate \" as sensory modifiers powders (F15), this formulation was added of 3.5% of Glycolic extract of cashew (F15C) and was stable in preliminary tests of stability. In the evaluation of in vitro sunscreen activity, the formulation showed FPS 50, Boost Factor classified as \"Good\" and critical wavelength above 370 nm. Cashew glycolic extract showed dose-dependent antioxidant activity. The characterization of the skin demonstrated that the group with oily skin showed higher transepidermal water loss, greater asperity and oiliness. Furthermore, computer analysis of images showed differences in the sebum, pores and comedones in the regions of the cheeks, chin and nose. In the sensory evaluation studies, the formulation F15C showed better scores on parameters related with touch, oiliness, smoothness, residual brightness, and showed higher purchase intent. No immediate effects were obtained in stratum corneum water content, transepidermal water loss and the parameters of microrelief. The formulation F15C presented retention of the sebum content compared with the formulation vehicle after two and four hours of application of the formulation. In the long-term effects study, the formulation provided a reduction in the number of pores on the chin and did not increase the comedones and didn\'t show significant changes in the parameters: stratum corneum water content, transepidermal water loss, parameters of the microrelief, sebum and counting active sebaceous glands. The formulation developed is presented as an innovative and efficient product with a pleasant sensory and compatible for use on oily skin. Furthermore, the cashew extract further improved the sensory properties of the formulation, showed antioxidant activity and clinical efficacy in the oil control and improvement of skin conditions.
15

Total Long-Chain n-3 Fatty Acid Intake and Food Sources in the United States Compared to Recommended Intakes: NHANES 2003–2008

Richter, Chesney K., Bowen, Kate J., Mozaffarian, Dariush, Kris-Etherton, Penny M., Skulas-Ray, Ann C. 27 September 2017 (has links)
The American Heart Association recommends consuming fish (particularly oily fish) at least two times per week, which would provide ae 0.5 g/day of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for cardiovascular disease risk reduction. Previous analyses indicate that this recommendation is not being met; however, few studies have assessed different ethnicities, subpopulations requiring additional n-3 fatty acid intake (i.e., children and pregnant and/or lactating women), or deciles of intake. Data from the National Health and Nutrition Examination Survey 2003-2008 was used to assess n-3 fatty acid intake from foods and supplements in the US population, according to age, sex, and ethnicity. A unique "EPA equivalents" factor, which accounts for potential conversion of shorter-chain n-3 fatty acids, was used to calculate total long-chain n-3 fatty acid intake. Data are reported for 24,621 individuals. More than 90% consumed less than the recommended 0.5 g/day from food sources (median = 0.11 g/day; mean = 0.17 g/day). Among the top 15% of n-3 fatty acid consumers, fish was the largest dietary contributor (71.2%). Intake was highest in men aged 20 years or more, and lowest in children and women who are or may become pregnant and/or are lactating. Among ethnicities, intake was lowest in Mexican-Americans. Only 6.2% of the total population reported n-3 fatty acid supplement use, and this did not alter median daily intake. Additional strategies are needed to increase awareness of health benefits (particularly among Mexican-Americans and women of childbearing age) and promote consumption of oily fish or alternative dietary sources to meet current recommendations.
16

Caracterização do processo de reciclagem do óleo lubrificante usado em postos de combustíveis e identificação de desafios frente à política nacional de resíduos sólidos /

Castro, Marcos Daniel Gomes de. January 2011 (has links)
Orientador: Rosani de Castro / Banca: Frederico Yuri Hanai / Banca: Ana Beatriz Lopes de Sousa Jabbour / Resumo: Segundo a Agência Nacional de Petróleo (ANP), o volume de óleo lubrificante comercializado no Brasil, tem contribuido para o crescimento da quantidade de resíduos descartados em postos de combustíveis, assim como outros estabelecimentos. Estes resíduos devem receber tratamento específico, conforme legislação vigente no Brasil: Política Nacional de Resíduos Sólidos (PNRS), resolução do Conselho Nacional do Meio Ambiente (CONAMA) 362/05, portarias Agencia Nacinoal do Petróleo (ANP) e a Norma Brasileira NBR 10004, que classifica o Óleo Lubrificante Usado ou Contaminado (OLUC), quanto seus aspectos de nocividade. O cenário é preocupante e envolve questões econômicas e ambientais. Á vista este trabalho tem como objetivo identificar qual o panorama atual do gerenciamento do OLUC nos postos de combustíveis e se os procedimentos adotados estão de acordo com a Nova Política Nacional de Resíduos Sólidos. Desenvolveu-se uma pesquisa quanti-qualitativa, através estudo exploratório com aplicação de um questionários e visita de campo em 70 postos de combustíveis dos municípios da 7ª Região Administrativa do Estado de São Paulo: Agudos, Arealva, Avaí, Balbinos, Bauru, Boracéia, Cabrália Paulista, Duartina, Fernão, Gália, Iacanga, Lençóis Paulista, Lucianópolis, Macatuba, Paulistania, Pederneiras, Pirajuí, Piratininga, Presidente Alves, Reginópolis, e Ubirajara. Técnicas estatísticas de análise multivariada e descritiva foram utilizadas para analisar para analisar as características de correlação dos municípios, além da qualificação das ações e gerencialmento do OLUC. Como principal resultado da dissertação na identificação do panorama atual do gerenciamento do OLUC destaca-se: (a) a integração dos atores da cadeia reversa do óleo lubrificante precisa ser fortalecida, aumentando, portanto a responsabilidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: According to the National Petroleum Agency (ANP), the volume of oil lubrificant marketed in Brazil, has contributed to the growth the amount of waste disposed at gas stations, so as other establishments. These wastes should be treated specifically, according to current law in Brazil: National Policy Solid Waste (PNRS), CONAMA (National Council of the Environment) 362/05, ordinances ANP (National Petroleum Agency) and the Standard Brazilian NBR 10004, which classifies or Used Lube Oil Contaminated (OLUC), and aspects of harm. The scenario is concern and involves economic and environmental issues. To view this study aims to identify the current landscape of Management OLUC at gas stations and the procedures adopted are consistent with the New National Policy on Waste Solids. Developed a quantitative and qualitative research through study exploratory application of a questionnaire and field visits in 70 gas stations in the municipalities of the 7th Administrative Regions of Sao Paulo State: Agudos, Arealva, Avaí, Balbinos, Bauru, Boracéia, Cabrália Paulista, Duartina, Fernão, Gália, Iacanga, Lençóis Paulista, Lucianópolis, Macatuba, Paulistania, Pederneiras, Pirajuí, Piratininga, Presidente Alves, Reginópolis, e Ubirajara. Statistical techiniques of descriptive and multivariate analysis were used to analyze the characteristics of correlation of municipalities and the qualification of actions to manage the OLUC. The results allow us to analyze the gas stations to adapt to managing the challenges of OLUC PNRs. The main result of the dissertation to identify the current landscape of management OLUC stand out: (a) the integration of actors in the chain reverse the lubrication oil needs to be strengthened, thereby increasig, therefore the shared responsability of those involved in the return of the waste on the... (Complete abstract click electronic access below) / Mestre
17

Istovremeni uticaj permeabilnosti sloja, prečnika vlakna i ulazne koncentracije uljne faze na separaciju mineralnih ulja iz otpadnih voda / Simultaneous effect of bed permeability, fiber diameter and oil phase inlet concentration on the separation of mineral oils from wastewater

Sokolović Srđan 26 June 2020 (has links)
<p>Cilj ove doktorske disertacije je da d&acirc; doprinos u proučavanju nedovoljno poznatih fenomena koalescentne filtracije, kako bi se smanjio obim potrebnih poluindustrijskih istraživanja prilikom projektovnja filtera za neku konkretnu primenu. Svi materijali kori&scaron;ćeni u ovoj doktorskoj disertaciji su otpadni materijali, čija primena kao filtarskog punjenja predstavlja poseban doprinos održivom razvoju. Jedan od ciljeva ove doktorske disertacije je proučavanje istovremenog uticaja promene permeabilnosti sloja i debljine vlakana na osobine sloja, pad pritiska i efikasnost separacije dispergovanog ulja iz kontinualne vodene faze. Uticaj geometrije sloja proučavan je na slojevima homogene i heterogene geometrije po dubini. Realizovano je detaljno ispitivanje izgleda, morfologije vlakana, kao i strukture sloja, izgleda i rasporeda njegovih pora, primenom skening elektronske mikroskopije i optičke mikroskopije. U radu je dat pregled istraživanja primene vlakana različite prirode (slobodnih i međusobno povezanih, krutih i elastičnih, različite debljine te time i različite vijugavosti) i njihovih slojeva. Takođe, dat je doprinos proučavanju istovremenog uticaja promena ulazne koncentracije dispergovane faze i permeabilnosti sloja. U veći deo ostvarenih istraživanja ukjučeno je i proučavanje uticaja prirode uljne faze, pri čemu je neophodno istaći da su sva kori&scaron;ćena ulja mineralnog porekla. Cilj optimizacije rada koalescera bio je da se pronađu uslovi u kojima se postiže maksimalna vrednost kritične brzine uz minimalni pad pritiska.</p> / <p>The aim of this doctoral dissertation is to contribute to the study of insufficiently known phenomena of coalescent filtration, in order to reduce the number of pilot plant experiments required for designing filters for some specific applications. All the used materials are waste materials the use of which as a filter media contributes to sustainable development. One of the goals of this doctoral dissertation is to study the simultaneous effect of changes in bed permeability and fiber thickness on bed properties, pressure drop and the efficiency of the dispersed oil separation from a continuous aqueous phase. The effect of bed geometry was studied by applying the beds of homogeneous and heterogeneous geometry in depth. A detailed examination of the appearance and morphology of the fibers, as well as the structure of the bed and the appearance and arrangement of its pores, was performed by scanning electron microscopy and optical microscopy. The doctoral dissertation gives an overview of the testing of fibers of different nature (free and interconnected, rigid and elastic, of different thickness and thus of different meandering) and their beds. The simultaneous effect of the changes in the input dispersed phase concentration and the bed permeability was also investigated. Much of the conducted research includes the study of the impact of the nature of the oil phase, and it is necessary to point out that all used oils are mineral oils. The goal of optimizing the operation of a coalescer was to find the conditions providing the maximum critical velocity value with a minimum pressure drop.</p>
18

[en] ELETROCOAGULATION APPLIED TO TREAT SOLUTIONS WITH HIGH CONCENTRATION OF OIL / [pt] ELETROCOAGULAÇÃO APLICADA A MEIOS AQUOSOS CONTENDO ÓLEO

ANTONIO GUTIERREZ MERMA 19 September 2008 (has links)
[pt] Efluentes oleosos são gerados de muitas fontes, tais como: indústrias petroquímicas, refinarias, plataformas de petróleo, fabricação de maquinarias, e até mesmo, no transporte, distribuição e armazenagem de óleo. O óleo presente na forma de emulsão é difícil de separar. Para quebrar essas emulsões, geralmente, são usados tratamentos químicos, biológicos, eletroquímicos, ultrafiltração. O processo de eletrocoagulação-flotação se inicia com a dissolução do anodo produzindo espécies aquosas (monoméricas, poliméricas) e precipitadas, espécies que funcionam como coagulantes e floculantes. As mesmas causam a desestabilização das emulsões através de mecanismos como a neutralização de carga superficial, ponte interparticular e coagulação por varredura, formando flocos de gotículas de óleo. A dissolução do metal no anodo é acompanhada da geração do gás hidrogênio no catodo. As bolhas são aderidas aos flocos, carregando-os até a superfície, onde são separados do reator, porém, dependendo da densidade deles, poderiam sedimentar-se. Neste trabalho, é avaliada a remoção de óleo de uma emulsão sintético pelo processo de eletrocoagulação-flotação. Avaliou-se a influência dos principais parâmetros de operação na taxa de redução da demanda química de oxigênio (DQO): concentração inicial do óleo; densidade de corrente; separação entre eletrodos; pH da solução; concentração de eletrólito. O efluente sintético foi preparado a partir de óleo Shell Talpa 30 e Oleáto de sódio como surfatante. Foi adicionado NaCl para aumentar a condutividade da solução. O pH inicial da emulsão foi de 8,70. O potencial zeta nessas condições teve um valor médio de -75mV, valor este que indicou a estabilidade da emulsão. / [en] The separation of emulsions or colloidal particles from wastewater is a major concern for the petroleum, metal manufacturing, food, textile, paper and hydrometallurgy industries. The emulsion present is very stable due to the presence of surfactants, so conventional methods can not be applied and it is necessary to combine one or two treatment processes for highly effective purification. Several techniques have been applied to treat these types of oily wastewater, e.g.: chemical, biological and electrochemical destabilization, ultrafiltration. Electrocoagulation is initiated by the oxidation of sacrificial anodes. The metal ions released combine to the hydroxyl ions produced at the cathode to form the corresponding metal hydroxides and others species, which cause the destabilization of the contaminants or particulate suspensions and form flocs. The bubbles hydrogen gas capturing and floating the flocs formed and separating from the liquid surface by scraping or settling depending on density of the flocs. In this work, the electrocoagulation technique was studied in order to treat concentrated oil-water emulsions chemically stabilized. This study was mainly focused on the effects of operating parameters such as: initial pH, current density, reaction time, NaCl concentration, electrode distance and inlet concentration on the abatement rate of chemical oxygen demand (COD). The synthetic emulsion was prepared from Shell - Talpa 30 oil (3g.L-1) and sodium dodecyl sulfate (1.0 g.L-1), also was added NaCl (3g L-1) for increasing the conductivity of the emulsion. Under those conditions we had a pH value around 8.70 and a zeta potential around -70mV, showing a good stability of the emulsion.
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AVALIAÇÃO DA APLICABILIDADE DE PROCESSOS BIOLÓGICOS NO TRATAMENTO DE EFLUENTES OLEOSOS COM ELEVADA CARGA ORGÂNICA / APPLICABILITY ASSESSMENT BIOLOGICAL PROCESSES IN OILY WASTEWATER TREATMENT WITH HIGH ORGANIC LOAD

Castro, Silvia Peres de 21 August 2009 (has links)
Made available in DSpace on 2015-09-25T12:23:37Z (GMT). No. of bitstreams: 1 Silvia Peres de Castro.pdf: 565210 bytes, checksum: bc1094dba26205895b29d51dc104b086 (MD5) Previous issue date: 2009-08-21 / The increasing global demand for energy and the diversity of manufactured products generates diverse residues that are frequently difficult to treat or degrade. The utilization of petroleum and its derivatives cause environmental damage via oil spillages and effluents generated by diverse processes such as car washes, petrol stations, public transport companies and even industrial kitchens. In this study a biological treatment was used as an alternative to treat these pollutants, which included two basic treatments to remove organic material: an aerobic process namely activated sludge and an anaerobic process, comprising a UASB reactor. The objective of this work was to treat by biological processes, a synthetic effluent derived from petroleum which characterized physico-chemically, as having oily characteristics, to evaluate comparatively the efficiency of organic matter removal via two different processes of biodegradation. The results obtained were submitted to statistical analysis by Box Plots and ANOVA at a significance level of 5%. The experimental work with bench scale activated sludge and UASB reactors was performed at The Experimental Station for the Biological Treatment of Sewage EXTRABES in Campina Grande - PB, using effluents synthesized in the laboratory to feed the reactors at elevated loads of organic matter containing lubricating oil and surfactants. The adopted treatments had significant organic carbon removal efficiencies; with values of 23.7 to 32% for aerobic treatment and 42 to 51% with anaerobic treatment thus demonstrating that UASB treatment was the more efficient process and could be adopted for the treatment of oily and surfactant-containing effluents. / A crescente demanda de energia necessária no mundo e a diversidade de produtos obtidos geram diversos resíduos difíceis de serem tratados. A utilização do petróleo e seus derivados causam danos ambientais, estes vêm desde os derramamentos de petróleo e seus componentes até mesmo de efluentes gerados nos mais diversos processos, como em lava-jatos, postos de combustíveis, empresas de transportes públicos e até mesmo em cozinhas industriais. Neste estudo utilizar-se-á tratamento biológico, como uma alternativa para o tratamento desses poluentes, dentre estes tratamentos tem se dois processos básicos para a remoção de material orgânico que foi estudado: os sistemas de lodos ativados e os reatores UASB. O objetivo desse trabalho foi tratar através de processos biológicos, efluentes sintéticos derivados do petróleo, bem como realizar a caracterização físico-química deste efluente oleoso, e determinar comparativamente a eficiência de remoção da matéria orgânica através de processos de biodegradação biológica. Os resultados obtidos foram submetidos a métodos estatísticos: estatística descritiva de distribuição (Box Plot) e análise de variância (ANOVA) fator único, com nível de significância de 5%. O trabalho experimental foi realizado na Estação Experimental de Tratamentos Biológicos de Esgotos Sanitários EXTRABES, localizado no bairro do Tambor na cidade de Campina Grande PB. Para a realização da pesquisa foram construídos, instalados e monitorados reatores de lodo ativado e UASB em escala de bancada. Os reatores foram alimentados com efluentes sintetizados no laboratório. Com esse procedimento buscou-se tratar biologicamente efluentes com elevada carga orgânica, contendo óleo lubrificante e substâncias surfactantes. Nos tratamentos adotados foi conseguido uma eficiência de remoção significativa, o tratamento aeróbio teve remoções de 23,7 a 32,1%, no tratamento anaeróbio a remoção da matéria orgânica foi de 51 e 42%, o que mostra que o tratamento anaeróbio utilizando o reator UASB teve uma melhor remoção da matéria orgânica, podendo esses tratamentos serem adotados para o tratamento de efluentes oleosos e surfactantes.
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O/W Emulsion Stabilised with Clay Particles and Anionic Surfactant as an Oily Sludge Model: Preparation, Characterization and Destabilization with Natural and Synthetic Polyelectrolytes / O/W-Emulsion stabilisiert durch Tonminerale und anionisches Tensid als Ölschlamm-Modellsystem: Herstellung, Charakterisierung und Destabilisierung in Gegenwart von natürlichen und synthetischen Polyelektrolyten

Rojas Reyna, Rosana del Coromoto 22 March 2011 (has links) (PDF)
Oily wastewater produced from petroleum and petrochemical refining processes is one of the gravest environmental threats. Oil waste ending up in sewers and dumps each year is equal to 25 times the amount of crude oil spilled in the Exxon Valdez accident (1989). Oil/Water separation covers a broad spectrum of industrial process operations. There are many techniques employed depending on each situation. The byproduct of water recovery from oily wastewater is a sludge rich in oil, surfactants and particles (oily sludge). The oily sludge still contains significant amounts of waters, which need to be recovered prior to its disposal. The use of polyelectrolytes for the flocculation of the emulsified oil and its separation from the aqueous phase is usually one of the steps of the wastewater as well as oily sludge treatment process. The efficiency of polyelectrolytes as floculants is quite often evaluated via trial and error and the appropriate polymer is selected according to the case. Even in scientific investigations it is rather common to use industrial oily sludge samples. The industrial oily sludge is characterized and treated by polyelectrolytes. Nevertheless industrial oily sludge is quite complicated and variable to be approximated by a model. For the systematic study of polyelectrolytes efficiency a stable, realistic and well-defined oily sludge model is necessary. In the present work an oily sludge model was successfully developed and characterized. The model consists on water, oil (kerosene), surfactant (sodium dodecyl sulphate, SDS) and clay particles (Blauton). The emulsifying efficiency of the surfactant and the clay were studied independently. The interactions between the surfactant and the clay including adsorption of the former on the later and cation exchange reactions were investigated. The four components were finally combined to form a series of emulsions varying the relative amounts of the emulsifiers for the highest stability to be encountered. Having concluded on the composition of the oily sludge model the efficiency of various polyelectrolytes was evaluated. Commercial natural (chitosans), synthetic (PolyDADMACs) polyelectrolytes and oilbreaks as well as lab-scale semi-synthetic polymers (modified chitosans) were tested. The flocculation efficiency was determined based on the amount and quality of water that was recovered as well as on the floc stability, size and sedimentation speed. The recovered water was characterized according to the environmental protection agency (EPA). The analysis included measurements on: total organic carbon (TOC), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS) and pH. Selection of the appropriate flocculant also depends on the type of flocs formed in combination to the treatment following the flocculation. When filtration or centrifugation is used as a post-flocculation process the appropriate polymers are those that form large and porous flocs, as the case of the modified chitosans AG95 and AG97. Clarification devices on the other hand require dense flocs as these produced by the use of PolyDADMACs, commercial chitosans, oilbreaks and modified chitosans GA35, GA41 and AG79. Regarding the water quality, some of the polymers used that have low values of COD, TOC and BOD5, may not need the secondary treatment (biological) prior to discharge, such as P187K (PolyDADMAC) and GA41 (modified chitosan). The others require a biological treatment for the regulation limits to be reached. The pH values of modified chitosans (except of AG97), lab-scale PolyDADMACs and an oilbreak (OCAA) are all in range of the regulation limits. The applicability of biopolymers as flocculants for oil sludge dewatering is a relatively new field of investigation. As a consequence of the growing demand for environmentally friendly technologies as well as renewable resources the interest on natural flocculants has increased. The aminopolysaccharide chitosan and its modified derivatives have outstanding properties such as biocompability, biodegradability, hydrophilicity, adsorption, flocculating ability and antibacterial properties. These natural polymers derived from the sea-food industry waste products would be very useful as residue oil adsorbents in any oily wastewater and can be among the most promising candidates as a replacement of the synthetic flocculants. / Ölhaltiges Abwasser, das bei Erdöl- und petrolchemischen Raffinierungsprozessen entsteht, ist eine der größten Umweltgefahren. Dieses Altöl landet jedes Jahr in der Kanalisation und in Deponien. Es handelt sich dabei um die 25-fache Menge an Rohöl, die beim Unfall der Exxon Valdez (1989) ausgeflossen ist. Die Öl/Wasser-Trennung überspannt ein breites Spektrum industrieller Prozesse. Es gibt viele Techniken, die abhängig von jeder Situation eingesetzt werden. Das Nebenprodukt bei der Abtrennung von Wasser aus ölhaltigen Abwässern ist ein Schlamm (Ölschlamm), der reich an Öl, Tensiden und Partikeln ist. Der Ölschlamm enthält noch bedeutende Mengen an Wasser, die vor ihrer Entsorgung verwertet werden müssen. Die Verwendung von Polyelektrolyten zur Ausflockung des emulgierten Öls und seine Trennung von der wässrigen Phase ist in der Regel einer der Schritte zur Behandlung von Abwässern sowie ölhaltigen Schlämmen. Die Effizienz von Polyelektrolyten als Flockungsmittel wird ganz häufig über Versuch und Fehler bewertet, und das passende Polymer wird entsprechend dem jeweiligen Fall ausgewählt. Sogar in wissenschaftlichen Untersuchungen ist es eher üblich, industrielle Ölschlamm-Proben zu verwenden. Der industrielle Ölschlamm wird charakterisiert und mit Polyelektrolyten behandelt. Dennoch ist der industrielle Ölschlamm ziemlich kompliziert und variabel und muss durch ein Modell angenähert werden. Für die systematische Untersuchung der Effizienz von Polyelektrolyten als Flockungsmittel ist ein stabiles, realistisches und klar definiertes Ölschlamm-Modell notwendig. In der vorliegenden Arbeit wurde ein Ölschlamm-Modell erfolgreich entwickelt und charakterisiert. Das Modell besteht aus Wasser, Öl (Kerosin), Tensid (Natriumdodecylsulfat, SDS) und Tonteilchen (Blauton). Die Emulgiereffizienz des Tensids und des Tons wurden unabhängig voneinander untersucht. Die Wechselwirkungen zwischen dem Tensid und dem Ton, die sowohl die Adsorption des Ersteren auf dem Letzteren einschließen als auch einen Kationenaustausch, wurden untersucht. Die vier Komponenten des Ölschlamm-Modells wurden schließlich kombiniert und es wurde eine Reihe von Emulsionen hergestellt, bei denen die relativen Mengen der Emulsionsmittel verändert wurden, um eine möglichst hohe Stabilität zu erreichen. Nachdem ein geeignetes Ölschlamm-Modell zur Verfügung stand, wurde die Effizienz der verschiedenen Polyelektrolyte als Flockungsmittel bewertet. Kommerzielle natürliche (Chitosane), synthetische (PolyDADMACs) Polyelektrolyte und Oilbreaks sowie Labor-semi-synthetische Polymere (modifizierte Chitosane) wurden getestet. Die Flockungseffizienz wurde sowohl basierend auf der Menge und Qualität des Wassers, das zurückgewonnen wurde, als auch bezogen auf die Flockenstabilität, die Flockengröße und die Sedimentationsgeschwindigkeit bestimmt. Das zurückgewonnene Wasser wurde entsprechend der Vorschriften der Behörde für Umweltschutz (EPA) charakterisiert. Die Analysen enthielten die Bestimmung des gesamten organischen Kohlenstoffs (TOC), des chemischen Sauerstoffbedarf (CSB), des biochemischen Sauerstoffbedarfs (BSB5), des Gesamtgehalts an suspendierten Partikeln (TSS) und die Bestimmung des pH. Die Auswahl geeigneter Flockungsmittel hängt auch von der Art der gebildeten Flocken, in Kombination mit der Behandlung, die den Flockungsprozess folgt, ab. Wenn als Postflockungsprozess Filtration oder Zentrifugation folgen, sollten Polymere verwendet werden, die große und poröse Flöckchen bilden, wie im Fall der modifizierten Chitosane AG95 und AG97. Andererseits verlangen Geräte zur Klärung von Abwässern dichte Flocken, wie solche, die beim Einsatz von PolyDADMACs, kommerziellen Chitosanen, Oilbreaks und den modifizierten Chitosanen GA35, GA41 und AG79 entstehen. In Bezug auf die Wasserqualität erhält man mit einigen der verwendeten Polymere so niedrige Werte von CSB, TOC und BSB5, dass wie im Falle von P187K (PolyDADMAC) und GA41 (modifiziertes Chitosan) keine biologische Sekundärbehandlung notwendig ist. Im Falle der anderen Polymere ist eine biologische Behandlung nötig, um die vorgeschriebenen Grenzen zu erreichen. Die pH-Werte der modifizierten Chitosane (außer der AG97), der im Labor hergestellten PolyDADMACs und des Oilbreak OCAA sind alle in Bereich der vorgeschriebenen Grenzen. Die Anwendbarkeit von Biopolymeren als Flockungsmittel für die Ölschlammentwässerung ist ein relativ neuer Forschungsbereich. Als Folge der wachsenden Nachfrage nach umweltfreundlichen Technologien sowie erneuerbarer Ressourcen hat das Interesse an natürlichen Flockungsmitteln zugenommen. Das Aminopolysaccharidchitosan und dessen modifizierte Produkte haben hervorragende Eigenschaften wie Biokompatibilität, Biodegradierbarkeit, Hydrophilie, Adsorption, die Fähigkeit zur Flockung und antibakterielle Eigenschaften. Diese natürlichen Polymere, die aus Meeresfrüchte-Industrieabfallprodukten gewonnen werden, sollten als Restöl-Adsorbentien bei der Aufarbeitung jedes ölhaltigen Abwassers sehr nützlich sein und können zu den vielversprechendsten Kandidaten als Ersatz der synthetischen Flockungsmittel werden.

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