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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.
171

Application of HTML/VRML to Manufacturing Systems Engineering

Krishnamurthy, Kasthuri Rangan 22 February 2001 (has links)
Manufacturing systems are complex entities comprised of people, processes, products, information systems and data, material processing, handling, and storage systems. Because of this complexity, systems must be modeled using a variety of views and modeling formalisms. In order to design and analyze manufacturing systems, the multiple views and models often need to be considered simultaneously. However, no single tool or computing environment currently exists that allows this to be done in an efficient and intelligible manner. New tools such as HTML and VRML present a promising approach for tackling these problems. They make possible environments where the different models can coexist and where mapping/linking between the models can be achieved. This research is concerned with developing a hybrid HTML/VRML environment for manufacturing systems modeling and analysis. Experiment was performed to compare this hybrid-modeling HTML/VRML environment to the traditional database environment in order to answer typical design/analysis questions associated with manufacturing systems, and to establish the potential advantages of this approach. Analyzing results obtained from the experiment indicated that the HTML/VRML approach might result in better understanding of a manufacturing system than the traditional database approach. / Master of Science
172

Application of Permutation Genetic Algorithm for Sequential Model Building–Model Validation Design of Experiments

Kianifar, Mohammed R., Campean, Felician, Wood, Alastair S. 08 1900 (has links)
Yes / The work presented in this paper is motivated by a complex multivariate engineering problem associated with engine mapping experiments, which require efficient Design of Experiment (DoE) strategies to minimise expensive testing. The paper describes the development and evaluation of a Permutation Genetic Algorithm (PermGA) to support an exploration-based sequential DoE strategy for complex real-life engineering problems. A known PermGA was implemented to generate uniform OLH DoEs, and substantially extended to support generation of Model Building–Model Validation (MB-MV) sequences, by generating optimal infill sets of test points as OLH DoEs, that preserve good space filling and projection properties for the merged MB + MV test plan. The algorithm was further extended to address issues with non-orthogonal design spaces, which is a common problem in engineering applications. The effectiveness of the PermGA algorithm for the MB-MV OLH DoE sequence was evaluated through a theoretical benchmark problem based on the Six-Hump-Camel-Back (SHCB) function, as well as the Gasoline Direct Injection (GDI) engine steady state engine mapping problem that motivated this research. The case studies show that the algorithm is effective at delivering quasi-orthogonal space-filling DoEs with good properties even after several MB-MV iterations, while the improvement in model adequacy and accuracy can be monitored by the engineering analyst. The practical importance of this work, demonstrated through the engine case study, also is that significant reduction in the effort and cost of testing can be achieved. / The research work presented in this paper was funded by the UK Technology Strategy Board (TSB) through the Carbon Reduction through Engine Optimization (CREO) project.
173

The Screening of Biomaterials to Support Long-term Growth and Maintenance of Human Embryonic Stem Cells in Xeno- and Feeder-free System

Pang, Justin Tse Wei 09 December 2013 (has links)
Current feeder-free culture systems employing undefined Matrigel are still more effective in maintaining human embryonic stem (ES) cells than defined surfaces using extracellular matrix (ECM) proteins. While the role of substrate stiffness in stem cell fate is becoming increasingly evident, all previous culture systems use ECM proteins on rigid polystyrene surfaces. Here, we used factorial designs to screen and evaluate combinations ECM proteins and substrate stiffness for their effect on short-term pluripotency and self-renewal. Using optimal conditions determined from our screening experiments, defined and near xeno-free culture systems maintained CA1 human ES cells for over 10 passages in Essential 8 (E8) medium. Under these conditions, we found that human ES cell self-renewal was greater on soft polydimethylsiloxane (PDMS) substrates than on rigid polystyrene dishes. The culture systems and screening tools developed in this project will help develop robust and defined xeno-free culture systems that incorporate both biochemical and biomechanical factors.
174

The Screening of Biomaterials to Support Long-term Growth and Maintenance of Human Embryonic Stem Cells in Xeno- and Feeder-free System

Pang, Justin Tse Wei 09 December 2013 (has links)
Current feeder-free culture systems employing undefined Matrigel are still more effective in maintaining human embryonic stem (ES) cells than defined surfaces using extracellular matrix (ECM) proteins. While the role of substrate stiffness in stem cell fate is becoming increasingly evident, all previous culture systems use ECM proteins on rigid polystyrene surfaces. Here, we used factorial designs to screen and evaluate combinations ECM proteins and substrate stiffness for their effect on short-term pluripotency and self-renewal. Using optimal conditions determined from our screening experiments, defined and near xeno-free culture systems maintained CA1 human ES cells for over 10 passages in Essential 8 (E8) medium. Under these conditions, we found that human ES cell self-renewal was greater on soft polydimethylsiloxane (PDMS) substrates than on rigid polystyrene dishes. The culture systems and screening tools developed in this project will help develop robust and defined xeno-free culture systems that incorporate both biochemical and biomechanical factors.
175

Relation between structure and properties of TiO2 coatings on metallic substrates / Relation entre la structure et les propriétés fonctionnelles des revêtements de TiO2 sur les substrats métalliques

Varghese, Aneesha Mary 19 April 2012 (has links)
L'objectif de cette étude était de réaliser des revêtements de TiO2 présentant une large variété de morphologies et d'établir des corrélations entre la structure de ces couches et leurs propriétés fonctionnelles, notamment la photocatalyse. Deux voies de synthèse employant le même précurseur, le tétra-isopropropoxide (TTIP) de titane, ont été utilisées, le procédé sol-gel et le dépôt chimique en phase vapeur (MOCVD). L'emploi de ces deux techniques permet de produire TiO2 sous une large gamme de morphologies mais avec des variétés polymorphiques similaires. Les revêtements synthétisés ont été caractérises afin de déterminer leur composition polymorphique, la taille des cristallites, la surface spécifique, la rugosité et l'épaisseur. Puis leur activité photocalytique pour la dégradation du bleu de méthylène a été déterminée. Par voie sol-gel, des dispersions de nano-cristallites de TiO2 dans l'eau, stables sur une longue durée (plus d'un an) en termes de composition polymorphique, taille d'agglomérats et de cristallites ont été synthétisées. Les revêtements ont été réalisés par tape-casting et dip-coating. Pour la synthèse en MOCVD, un plan d'expérience (PeX) a été utilisé, à notre connaissance pour la première fois. Il a permis de déterminer, d'une manière efficace et économique (avec un nombre minimum de tests expérimentaux), les paramètres les plus importants du procédé contrôlant les diverses propriétés quantifiables du revêtement. Il a aussi permis de mettre en évidence les interactions entre les paramètres de synthèse et leur effet sur la structure du revêtement. Les conclusions tirées du PeX sont en accord avec les résultats obtenus lors des études précédentes. L'analyse en composantes principales (ACP) a été réalisée pour avoir une vue globale de la façon dont les diverses propriétés des revêtements sont reliées entre elles / The overall objectives of this study was to find an environmental-friendly and simple procedure to synthesize titanium-dioxide, as well as, to determine the relation between the structural and functional properties of titanium dioxide coatings. Both of these objective have been attained in this study. By the sol-gel technique, titanium dioxide sols were synthesized by the hydrolysis of titanium(IV)isopropoxide. Nanocrystalline dispersions of TiO2 in water were prepared that were suitable for coatings and having long-term stability (more than 1 year) in terms of polymorphic composition, crystallite and agglomerate size. A design of experiments (DoE) was utilised, to our knowledge, for the first time in MOCVD for the synthesis of TiO2 coatings. It was employed to determine, in a timely and economical manner, the most significant process parameters for any quantifiable property of the coating and to highlight the interaction between these operating parameters, as well as, the correlation between the structure of the coating and the process. The conclusions drawn from the DoE were compared to results obtained by previous studies and were found to concur. Therefore, the DoE was successful in screening the most important process parameters, with a minimum number of experimental trials. For most of the properties that were under investigation, the DoE showed that, the deposition temperature and reactor pressure were, often-times, the most significant. Therefore, to change the microstructure and composition of MOCVD coatings, changing these process parameters will ensure the highest impact. It has to be stressed that the conclusions drawn from the DoE are restricted to the experimental range that was under investigation. Principal Component Analysis (PCA) was conducted to have an overall view of how the different properties of the coatings related with one another. The interpretations made from this analysis were that the photocatalytic (PC) activity of the coatings produced did not relate strongly to the polymorphic composition, which is contrary to literature review and is explained to be a result of the different morphologies that lead to different porosities and specific surface area. The PC activity did not depend on the mass over a critical mass. With this analysis it appeared to be clear that the porosity and specific surface area played a larger role than polymorphic composition. This hypothesis has to be verified because we did not succeed in determining the specific surface area of our coatings during this study. However, some preliminary tests have been conducted showing that cyclic voltametry could be used to evaluate the surface area of our films
176

Développement d’outils prédictifs de la teneur en composés sensibles à l’oxydation au cours de la conservation dans les matrices nutritionnelles / Development of predictive tools for the content of oxidation-sensitive compounds during storage in nutritional matrices

Yessaad, Mouloud 12 December 2018 (has links)
Lors de leur conservation, les principes actifs (médicaments, nutriments) peuvent être sujets à une dégradation susceptible de modifier leurs propriétés initiales et les rendre non disponibles. Aussi, les industriels et les pharmaciens hospitaliers réalisant des préparations pharmaceutiques et/ou des compléments alimentaires ont-ils la nécessité de réaliser des études de stabilité. Ces études sont longues et coûteuses car elles doivent tenir compte de tous les paramètres environnementaux susceptibles d’influencer la stabilité du principe actif, de la matrice et du conditionnement. L’objectif de cette thèse consiste à développer un outil qui permet d’estimer les taux de dégradation des vitamines et de se projeter sur la durée de vie de principes actifs nutritionnels en se basant sur l’utilisation des modèles de calcul intégrant à la fois les caractéristiques des produits, matrice et des conditions de conservation. Le projet s’est déroulé en plusieurs phases en ciblant les vitamines hydrosolubles. Tout d’abord, un développement et validation d’une méthode de dosage chromatographique qui permet de quantifier toutes les vitamines en une seule analyse sans interférence avec les éventuels produits de dégradation. Une étude de l’influence des paramètres les plus importants a été réalisée via un plan d’expériences. Les cinétiques de dégradation ont été étudiées et modélisées en plusieurs approches. A partir du modèle le plus adapté, un premier niveau de simulation a été conçu permettant de déterminer les facteurs d’influence pertinents dans la dégradation des vitamines au regard des données exploitables. Le livrable, le calculateur, devrait ainsi permettre de guider les utilisateurs industriels et hospitaliers dans le choix des conditions d’étude de vieillissement accéléré. / When stored, the active ingredients (drugs, nutrients) may be subject to degradation that may change their original properties and make them unavailable. In addition, manufacturers and hospital pharmacists carrying out pharmaceutical preparations and / or dietary supplements have the need to carry out stability studies. These studies are long and costly because they must consider all the environmental parameters likely to influence the stability of the active principle, the matrix and the packaging. The aim of this thesis is to develop a tool that allows to estimate the degradation rates of vitamins and to project on the life span of nutritional active principles based on the use of computational models integrating at the same time product characteristics, matrix and storage conditions. The project took place in several phases targeting the water-soluble vitamins. First, a development and validation of a chromatographic assay method that quantifies all vitamins in a single analysis without interference with any degradation products. A study of the influence of the most important parameters was carried out with a design of experiments. The kinetics of degradation have been studied and modeled in several approaches. From the most appropriate model, a first simulation level was designed to determine the relevant influencing factors in the degradation of vitamins in terms of exploitable data. The deliverable, the calculator, should thus help guide industrial and hospital users in the choice of accelerated aging study conditions.
177

Parâmetros mais influentes na previsão da diluição inicial em sistemas de emissários submarinos: uma contribuição baseada em técnicas de planejamento de experimentos e superfícies de resposta. / More influential parameters in the prediction of initial dilution in submarine outfall systems: a contribution based on techniques of design of experiment and response surfaces.

Yanes, Jacqueline Pedrera 14 December 2017 (has links)
As simulações computacionais são comumente empregadas no estudo do processo da dispersão da pluma de efluente de esgoto no mar como suporte no projeto de sistemas de emissários submarinos. Os modelos de campo próximo são uma ferramenta eficiente para prever o comportamento desses sistemas, através da previsão da diluição inicial, das principais dimensões da pluma e da concentração final de poluentes, informações úteis para o projeto do difusor. Usando modelos de campo próximo, como o NRFIELD e o UM3 do Visual Plumes, é possível simular diferentes alternativas de emissários. No entanto, a realização de muitas simulações resulta numa grande quantidade de informações que impede a obtenção de conclusões objetivas, consumindo muito tempo do projeto. Uma estratégia para um processo de simulação eficiente que permita a obtenção da máxima informação possível com um número mínimo de simulações é fundamental. Na análise dos resultados de simulações nas quais seus parâmetros de entrada são modificados de forma controlada, as causas das mudanças na resposta podem ser facilmente identificadas. Devido a isto, o uso da análise estatística foi considerado. As ferramentas estatísticas podem ser úteis na organização das simulações e na análise subsequente dos resultados. O Planejamento de Experimentos (DOE) é a metodologia estatística para uma experimentação eficiente, permitindo a identificação das variáveis estatisticamente significativas em qualquer sistema ou processo e, a Metodologia de Superfície de Resposta permite a otimização de sistemas a partir de suas variáveis estatisticamente significativas. Considerando isso, o objetivo principal desta pesquisa foi apresentar uma nova abordagem para otimizar, por meio da simulação computacional com modelos de campo próximo e da utilização das ferramentas estatísticas: Planejamento de Experimentos e Superfícies de Resposta, a quantidade de simulações necessárias para a obtenção do valor de diluição inicial mais próximo do ótimo, no projeto de emissários submarinos, através da identificação das variáveis estatisticamente significativas, na predição da diluição inicial, nos modelos de campo próximo do Visual Plumes. Os resultados do trabalho mostraram que só três variáveis geométricas, da configuração do difusor de um emissário, são estatisticamente significativas para a previsão da diluição inicial, e que apenas umas poucas simulações, estatisticamente planejadas, são indispensáveis para a obtenção de uma configuração de emissário mais eficiente. / The computational simulations are commonly employed in the study of the process of dispersion of sewage plume at sea as support in the design of submarine outfall systems. The near field models are an efficient tool to predict the behavior of these systems, by predicting the initial dilution, the main dimensions of the sewage plume and the final concentration of pollutants, useful information for the design of the diffuser. Using near field models such as NRFIELD and UM3 from Visual Plumes, it is possible to simulate different submarine outfall alternatives for their posterior comparison and analysis. However, when many simulations are conducted, it is resulted a large amount of information, which make more difficult to obtain objective conclusions and it is much more time consuming solution. A strategy for an efficient simulation process, that allows obtaining the maximum possible information with a minimum number of simulations, is quite fundamental. In the analysis of the results of simulations in which its input parameters are modified in a controlled way, the causes of the changes in the response can be easily identified. Because of this, the use of statistical analysis was considered. Statistical tools can be useful in organizing the simulations and in the subsequent analysis of the results. The Design of Experiments (DOE) is the statistical methodology to guarantee an efficient experimentation, allowing the identification of the statistically significant variables in any system or process, and the Response Surface Methodology allows the optimization of the systems using their statistically significant variables. Considering this, the main objective of this research was to present a new approach to optimize, through computational simulation with near field models and the use of statistical tools: Design of Experiments and Response Surfaces Methodology, the number of necessary simulations to obtain the initial dilution value closer to the optimum, in the design of submarine outfalls, through the identification of the statistically significant variables, in the prediction of the initial dilution, in the near field models. The results of the work showed that only three of the diffuser geometric variables are statistically significant for the initial dilution prediction, and that only a few statistically planned simulations are indispensable for obtaining a more efficient submarine outfall configuration.
178

Estudo da aplicação de ZnO fotoirradiado com luz solar no tratamento de efluentes de laticínios / Study of application of ZnO using solar photoirradiation in dairy wastewater

Samanamud, Gisella Rossana Lamas 28 February 2011 (has links)
Os produtos lácteos são tidos como os alimentos mais perfeitos para o homem devido ao seu alto valor nutritivo. Entretanto, esses produtos vêm refletidos na elevada carga orgânica de efluente gerado. Os Processos Oxidativos Avançados (POA) são métodos químicos baseados na geração de radicais hidroxilas, que promovem a oxidação de compostos orgânicos. O uso de semicondutores no tratamento de efluentes tem sido de grande interesse devido à sua alta eficiência, estabilidade fotoquímica, natureza não-tóxica e baixo custo, especialmente quando a luz do sol é usada como fonte de irradiação. O uso de Óxido de Zinco (ZnO), por exemplo, além de mais econômico, absorve uma fração maior de espectro UV e tem melhor desempenho em pH neutro. Este estudo consistiu em avaliar a aplicação e eficiência da fotocatálise heterogênea (POA) solar com ZnO em termos de percentual de degradação de Carga Orgânica Total (COT) para um posterior tratamento biológico aerado visando melhorar as condições de despejo do efluente de modo a preservar o ecossistema e economia dos recursos naturais. O sistema POA consistiu de um volume fixo de efluente de 3L, de uma chapa metálica 800 x 250 mm revestida com uma formulação de tinta contendo ZnO, um reservatório de vidro, uma bomba centrífuga e aberto para absorção de radiações UV solar. Os resultados foram obtidos e analisados a partir do método de planejamento de experimentos em termos de percentual de degradação de COT. O melhor resultado apresentou um percentual de degradação de COT de 31,5% onde os níves das variáveis estudadas ocorreram em pH 8,0 em chapa de ZnO com espessura de 100 micrômetros (?m), utilizando o efluente in natura e o tempo total de reação de 3 h (180min). O efluente tratado pelo POA solar com ZnO foi submetido ao tratamento biológico aerado. O pH ótimo e a concentração de lodo foram de 6,0 e 5,0 mg/L, respectivamente. O percentual de degradação de COT para os tratamentos combinados foi de 75,1 % para o efluente de laticínios utilizado neste estudo. Isto sugere que o tratamento por POA utilizando ZnO seguido de um Tratamento Biológico Aerado seria uma alternativa promissora no tratamento de efluentes de laticínios. / Dairy products are the most perfect type of food for men due to its high nutritive value reflected on its high organic load of wastewater generated. The Advanced Oxidation Processes (AOP) are chemical methods based on the generation of hydroxyls radicals that promote the oxidation of organic compounds. The use of semiconductors in wastewater treatment has been of great interest owing to its high efficiency, photochemical stability, non-toxic nature and lower costs, especially when sunlight is used as source of irradiation. The use of Zinc Oxide (ZnO), for instance, besides being more economic, it also absorbs a greater range of UV spectrum and it has a better performance on neutral pH. This study consisted in evaluating the application and efficiency of solar photocatalytic oxidation (AOP) with ZnO in percentage terms of removal of Total Organic Carbon (TOC) prior to an aerobic biological treatment aiming to improve the conditions of the disposal of this wastewater in order to conserve the water environment and saving natural resources. The AOP system consisted of a working volume of 3 L, a sheet metal 800 x 250 mm covered with a paint formula containing ZnO, a glass vessel, a pump and an open system in order to collect solar UV radiation. The results were obtained and analyzed from design of experiments in terms of percentage of removal of TOC. The maximum percentage was found to be 31.5 % of removal of TOC and at pH 8.0, thickness of the sheet containing ZnO of 100 micrometers (?m), wastewater in natura and total time of reaction of 3 h (180 min). The solar AOP with ZnO treated wastewater was subjected to an aerobic biological treatment. The optimum pH and sludge loading were of 6.0 and 5.0 mg/L, respectively. The combination of both treatments resulted in 75.1 % of removal of TOC from the dairy wastewater used in this study. This suggests that the AOP using ZnO followed by an aerobic biological treatment would be a promising alternative for the treatment of dairy wastewater.
179

Otimização da síntese de poliacrilamida catiônica em emulsão / Optimization of cationic polyacrylamide emulsion synthesis

Pegoraro, Danilo Silva 06 May 2016 (has links)
Polímeros e copolímeros hidrossolúveis a base de acrilamida e seus derivados são sintetizados e aplicados principalmente como floculantes, auxiliando na remoção de sólidos finos presentes em águas residuais e industriais. As poliacrilamidas, como são assim chamadas, podem se apresentar em sua forma neutra ou contendo diferentes cargas iônicas (positivas ou negativas) em sua composição em função do tipo de aplicação específica. As poliacrilamidas são sintetizadas, em sua grande maioria, através de emulsões inversas via polimerização radicalar, visando à elevada massa molar do polímero formado. A formulação da poliacrilamida catiônica com fração molar de 0,6 do comonômero iônico foi otimizada através de planejamento fatorial experimental, variando-se os principais fatores de processo: concentração do pacote de surfactante para formação da emulsão inversa, tempo de micronização, concentração de VISCOPLEX® e concentração de ácido graxo. Com base nos resultados obtidos a partir do primeiro planejamento, foram estudadas as seguintes variáveis: HLB do sistema de surfactantes e a troca dos surfactantes monoméricos por surfactantes poliméricos. A otimização da formulação levou em conta principalmente o custo-benefício para produção e comercialização em escala industrial. O fator micronização foi elevado em seu máximo e os fatores VISCOPLEX® e ácido graxo foram excluídos da formulação, após conclusão dos estudos. A troca dos surfactantes monoméricos por poliméricos foi vantajosa devido ao ganho de qualidade do produto final, mesmo com maior custo de implementação. Para minimizar os custos de formulação o fator HLB foi utilizado em seu máximo, onde houve incremento do ALKONAT® L 50 para formação da emulsão inversa. / Acrylamide based hydrosoluble polymers and copolymers and their derivatives are synthesized and mainly applied as flocculants, assisting removal of fine solids present in wastewater and industrial wastewater. Polyacrylamides may be present in their neutral form or with different ionic charges (positive or negative) in their composition depending on the type of specific application. Polyacrylamides are synthesized, mostly by inverse emulsions using radical polymerization, aiming polymers with high molecular weight. Cationic polyacrylamide formulation with 0.6 mole fraction of the ionic comonomer was optimized through design of experiments (DOE), varying the major process factors: surfactant package concentration to form inverse emulsion, micronization time, VISCOPLEX® concentration and fatty acid concentration. Based on the responses from the first DOE, a second DOE was performed, where the variables surfactant system HLB and the exchange of monomeric surfactant by polymeric surfactants were investigated. The formulation optimization considered mainly cost-effective production and industrial scale. The micronization factor was set at its maximum and VISCOPLEX® and fatty acid factors were excluded from the formulation, after conclusion of studies. Exchanging monomeric surfactants by polymeric surfactants led to a final product with higher quality, even considering a higher implementation cost. In order to minimize formulation costs HLB factor was used at its maximum, increasing the content of ALKONAT® L50 to form the inverse emulsion.
180

Influência do sulfato na produção de metano a partir de vinhaça de cana-de-açúcar / The influence of sulfate on the production of methane from sugarcane vinasse

Barbosa, Raphaella Machado 18 September 2018 (has links)
O Brasil é o maior produtor mundial de cana-de-açúcar e também o primeiro do mundo na produção de açúcar e etanol, o biocombustível mais utilizado como alternativa energética no país (BRASIL, 2017). No entanto, esse processo produtivo precisa considerar os subprodutos gerados, principalmente a vinhaça, que se não tratada e disposta corretamente podem causar problemas ambientais sérios. Sendo um efluente com alta carga orgânica, a vinhaça concentra potencial substancial para geração de bioenergia como o metano. Este trabalho teve como objetivo avaliar a influência da concentração de sulfato, advindo da utilização de ácido sulfúrico para manutenção da pureza das cepas fermentativas e incorporado à vinhaça, na produção de metano. Para tanto, testes em batelada foram feitos com relações DQO/Sulfato diferentes. As respostas obtidas no planejamento experimental fatorial 22 com ponto central, utilizando a demanda química de oxigênio (DQO) e sulfato como os fatores, foram a produção de metano, a eficiência de remoção de matéria orgânica e a eficiência de remoção de sulfato ao longo dos ciclos de operação. As faixas estudadas foram de 4,6 a 2,0 gDQO.L-1 e 0,3 a 2,3 gSO4-2.L-1. Dessa forma, para o intervalo de concentrações testadas, a quantidade de matéria orgânica foi o fator mais importante para a produção de metano, e foi constatado que o sulfato possuiu efeito negativo em sua produção. Para a eficiência de remoção de matéria orgânica, a interação dos fatores foi a mais significativa, mostrando que a participação das bactérias redutoras de sulfato foi positiva, aumentando a eficiência de remoção. Com relação à eficiência de remoção do sulfato, apenas a concentração de sulfato foi significativa para a remoção do mesmo, quanto maior a concentração menor foi a eficiência de remoção observada. A maior produção de metano ocorreu na condição 4,6 gDQO.L-1 e 0,3 gSO4-2.L-1, DQO/SO42- de 12,5, em que a eficiência de remoção de matéria orgânica foi de 80% e a de sulfato foi de 89%. A biomassa desenvolveu as rotas metanogênica e sulfetogênica, sendo a metanogênica responsável pela maior eficiência de remoção (85% do total). Sequenciamento Illumina MiSeq 16S rRNA foi feito no inóculo utilizado nos experimentos, indicando a presença abundante das bactérias capazes de produzir acetato (54,75%), dentre elas o gênero Desulfofaba (Bactéria Redutora de Sulfato Oxidativa Incompleta, 7,08%), mostrando uma predisposição da rota metanogênica pela via do acetato ser a predominante. / Brazil is the world\'s largest producer of sugarcane and the world\'s leading producer of sugar and ethanol, the most used biofuel as an energy alternative in the country (BRASIL, 2017). However, this productive process needs to consider the by-products generated, especially the vinasse, which if not treated and disposed properly can cause serious environmental problems. Being an effluent with high organic load, vinasse concentrates potential for bioenergy generation as methane. The objective of this work was to evaluate the influence of the sulfate concentration, resulting from the use of sulfuric acid to maintain purity of fermentative strains and incorporated into vinasse, in the production of methane. For that, batch tests were done with different COD/SO42- ratios. The responses obtained in the 22 design of experiment with central point, using the chemical oxygen demand (COD) and sulfate, as the factors were the methane production, the organic matter removal efficiency and the sulfate removal efficiency along the cycles of operation. The ranges studied were 4.6 to 2.0 gDQO.L-1 and 0.3 to 2.3 gSO42-.L-1. Therefore, for the range of concentrations tested, the amount of organic matter was the most important factor for the production of methane, and it was verified that the sulfate had a negative effect on its production. For the removal efficiency of organic matter, the interaction of the factors was the most significant, showing that the participation of the sulfate reducing bacteria was positive, increasing the removal efficiency. Regarding the sulfate removal efficiency, only the sulfate concentration was significant for the removal of itself, the higher the concentration the lower the observed removal efficiency. The highest methane production occurred in the condition 4.6 gDQO.L-1 and 0.3 gSO4-2.L-1, COD/SO42- of 12.5, where the removal efficiency of organic matter was 80% and sulfate was 89%. The biomass developed the methanogenic and sulfetogenic routes, being the methanogenic responsible for the greater removal efficiency (85% of the total). Sequencing Illumina MiSeq 16S rRNA was done in the inoculum used in the experiments, indicating the abundant presence of bacteria capable of producing acetate (54.75%), among them the genus Desulfofaba (Incomplete Oxidative Sulfate Reducing Bacteria, 7.08%), showing a predisposition of the methanogenic route through the acetate route is the predominant one.

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