421 |
Vytvoření metodiky zavádění systému managementu hospodaření s energií ve výrobním podniku / Development and implementation of energy savings and energy management methodology in an industrial enterpriseDudarev, Ivan Unknown Date (has links)
V současné době se problematika energetických úspor dostává do popředí zájmu jak na úrovni jednotlivých podniků, tak i na úrovni celého státu. Často bývá příčinou sporů ve vědeckých kruzích i mezi odborníky z praxe. Lidstvo tradičně začalo využívat energii z minerálních přírodních zdrojů, které však ve srovnání s obnovitelnými zdroji energie mají omezení. Výzkum a implementace moderních technologií jsou ztíženy otázkou investic a časově omezeny. Proto se evropská strategie energetické bezpečnosti zaměřuje na energetickou účinnost, která je jedním z nejefektivnějších způsobů zlepšení bezpečnosti spotřeby energie. Velké společnosti a podniky jsou jedním z hlavních spotřebitelů energie. Proto je tato vědecká práce zaměřena na problematiku úspor energie a zlepšování energetické účinnosti podniku. Těžiště práce spočívá ve vytvoření a zavedení metodiky pro úsporu energie a managementu hospodaření s energií ve výrobním procesu automobilového podniku. Dále je pro účely této práce vytvořen a popsán způsob vizualizace spotřeby energie v prostředí virtuální reality
|
422 |
Design and configuration of sustainable dynamic cellular manufacturing systems / Configuration de systèmes de production cellulaires dynamiques et durablesNiakan, Farzad 07 December 2015 (has links)
La révolution la plus récente dans l'industrie (révolution industrielle 4.0) nécessite une plus grande flexibilité, agilité et efficacité dans l'utilisation des équipements de production. Le système manufacturier cellulaire dynamique (DCMS) est l'un des meilleurs systèmes de production qui répondent à ces exigences. En outre, l'importance croissante du développement durable force les fabricants et les gestionnaires à prendre en compte les enjeux environnementaux et sociaux dans la conception et la configuration des systèmes de fabrication. Cette thèse porte sur la configuration durable des DCMS en proposant trois modèles mathématiques. Le plus grand challenge de cette étude est (i) de choisir des critères sociaux et environnementaux appropriés, (ii) de les intégrer dans des modèles mathématiques et (iii) d'étudier l'impact de ces critères sur des DCMS. Le premier modèle est bi-objectif afin de faire un compromis entre certains critères sociaux (offres d'emplois, risques de la machine, etc.) et économiques (divers coûts liés à la formation de cellules). Pour être plus proche de situations de la vie réelle, certains paramètres tels que la demande, les coûts liés aux machines et la capacité en temps des machines sont considérés comme incertains. Pour résoudre ce problème, une méthode d'optimisation robuste est appliquée pour faire face à cette incertitude. Dans le deuxième modèle, toutes les dimensions du développement durable sont prises en compte dans le modèle mathématique bi-objectif proposé. La première fonction objectif modélise des critères économiques (coûts) et la seconde des aspects environnementaux (déchets de production), tandis que certaines contraintes représentent des questions sociales (principalement le « Daily Noise » à cause de la complexité de calcul). En raison de la NP-difficulté du problème, une nouvelle approche novatrice appelée NSGA II-MOSA est proposée. Le troisième modèle proposé a trois fonctions objectif, une pour chaque type d’enjeux : environnemental, social et économique. Afin d'être proche de la vie réelle, certains paramètres du modèle sont exprimés en termes de valeur floue. Nous proposons une méthode possibiliste hybride pour faire face à l'incertitude et une approche floue interactive est considérée pour résoudre un modèle multi-objectif déterministe pour des solutions de compromis. Enfin, la dernière partie de la thèse étudie la possibilité d'appliquer les trois modèles proposés à l’industrie grâce à une méthode plus facile. Une approche d'optimisation-simulation innovante est introduite pour faire face à la configuration de DCMS : (i) La phase d'optimisation fonctionne comme méthode de fractionnement de scénarii pour réduire le nombre de configurations alternatives en se concentrant sur les niveaux stratégique et tactique. (ii) Ensuite, un outil de simulation détaille le niveau opérationnel en étudiant la performance de chaque alternative et l'interaction entre plusieurs composants de cellules. / The most recent revolution in industry (Industrial Revolution 4.0) requires increased flexibility, agility and efficiency in the use of production equipment. Dynamic Cellular Manufacturing System (DCMS) is one of the best production systems to meet such requirements. In addition, the increasing importance of sustainable development forces manufacturers and managers to take account of the environmental and social issues in the design and configuration of manufacturing systems. This thesis focuses on the sustainable configuration of DCMS by proposing three mathematical models. The main challenge of this study is to (i) choose appropriate social and environmental criteria, (ii) integrate them in mathematical models, and (iii) study the impact of these criteria on DCMS. The first model is bi-objective in order to make a trade-off between some social (job opportunity, potential machine hazards, etc.) and economic (various costs related to cell formation) criteria. To get closer to real-life situations, some parameters such as demand, machine-related costs and time capacity of the machines are considered as uncertain. To solve this problem, a robust optimization method is applied to cope with this uncertainty. In the second model, all dimensions of sustainable development are taken into account in a new bi-objective mathematical model. The first objective function models economic criteria (costs) and the second one environmental aspects (production waste), while social issues (mainly Daily Noise Dosage because of computational complexity) are modeled as constraints. Due to the NP-hardness of the problem, a new innovative approach called NSGA II-MOSA is proposed. The last model has three objective functions, one for each dimension of the sustainable development: environmental, social and economic. In order to be close to real life, some parameters of the model are expressed in terms of fuzzy value. We propose a hybridized possibilistic method to deal with uncertainty and an interactive fuzzy approach is considered to solve an auxiliary crisp multi-objective model in order to find trade-off solutions. Finally, the last part of the thesis studies the possibility to apply the three proposed models to the industry thanks to an easier method. A novel optimization-simulation approach is introduced to deal with the configuration of DCMS: (i) the optimization phase operates as scenario fraction method in order to reduce the number of alternative configurations by focusing on strategic and tactical levels; (ii) next, a simulation tool investigates the operational level by studying the performance of each alternative and the interaction between several components of the cells.
|
423 |
Produtividade de cultivares de batata e atributos de qualidade para processamento industrial nas formas de palha e chips / Yield efficiency and industrial attributes of potatoes cultivars for shoestring and chipsAraujo, Thaís Helena de 20 January 2014 (has links)
O mercado brasileiro de processamento de batata tem mostrado expressivo crescimento nos ultimos anos. No entanto, sua expansao e condicionada pelo suprimento de materia-prima adequada ao processamento industrial. As principais industrias de batata frita priorizam cultivares aptas para cada forma de processamento, pois a escolha correta da cultivar contribui para a reducao do custo de producao e para o aumento do rendimento e da qualidade do produto final. O objetivo dessa pesquisa foi estudar a eficiencia produtiva, a aptidao culinaria e as caracteristicas das cultivares de batata quando processadas na forma de palha e chips. Avaliou-se nove cultivares de batata: Agata, Almera, Arizona, Caruso, Destiny, Excelence, Fontane, Markies e Saviola. \'Agata\' e \'Almera\' foram utilizadas como cultivares nao aptas para fritura e \'Fontane\' e \'Markies\' como cultivares recomendadas para fritura. O ensaio foi conduzido no periodo de janeiro a maio de 2013, nas condicoes ambientais de Nova Resende, na regiao Sudoeste de Minas Gerais. As cultivares Arizona, Caruso, Agata e Markies exibiram o maior potencial produtivo e, junto a Saviola, a maior producao de tuberculos comerciaveis. Os teores mais elevados de materia seca foram exibidos por \'Destiny\' e \'Caruso\' (superior a 20%), seguidas por \'Excelence\', \'Fontane\' e \'Markies\' (17 a 18%). \'Caruso\' proporcionou o maior rendimento de fritura em ambas as formas de processamento. As cultivares Destiny, Excelence (ambas com cor amarela extremamente clara apos a fritura), e Caruso (cor dourada) na forma de palha; e Caruso e Destiny (cor amarela clara a dourada) na forma de chips apresentaram baixos teores de acucares redutores. Entre as cultivares avaliadas a maior eficiencia produtiva de materia-prima com aptidao para fritura foi exibida por \'Caruso\', \'Destiny\' e \'Excelence\', sendo que todas sao aptas ao processamento na forma de palha. Ja na forma de chips somente \'Destiny\' e \'Caruso\' proporcionaram fritas adequadas. / There is an increasing market for potato processing in Brazil, and the expansion of the potato industry can only be sustained if good quality product supplies of raw material are available. To reduce production costs and increase industrial efficiency, the industry must choose appropriated cultivars for each kind of product. This research investigated the tuber yield, frying aptitude, and the potato quality attributes for shoestring and chips. Nine potatoes cultivars were evaluated: Agata, Almera, Arizona, Caruso, Destiny, Excelence, Fontane, Markies and Saviola. \'Agata\' and \'Almera\' were considered unfit for frying, \'Fontane\' and \'Markies\' with frying standards. The trial ran from January to May 2013, in the south-west region of Minas Gerais State, Brazil. The cultivars Arizona, Caruso, Agata and Markies exhibited higher yield potential. These cultivars and Saviola obtained the highest marketable tubers. \'Destiny\' and \'Caruso\' showed the highest dry matter contents (higher than 20%) and were followed by \'Excelence\', \'Fontane\' and \'Markies\' (17- 18%). \'Caruso\' showed greater industrial efficiency for shoestring and chips. \'Destiny\', \'Excelence\' (extra light fries) and Caruso (medium light) for shoestring, and Caruso and Destiny (extra light to medium light) for chips showed low contents of reducing sugars. It was concluded that \'Destiny\', \'Excelence\' and \'Caruso\' outperformed all other cultivars in terms of yield. Besides, these varieties also displayed aptitude for shoestring frying. On the other hand, \'Destiny\' and \'Caruso\' were apt to frying as chips.
|
424 |
Potencial do reator anaeróbio de leito fixo-estruturado e fluxo descendente para o tratamento de drenagem ácida de minas em co-digestão com vinhaça / Down-flow fixed-structured bed anaerobic reactor potential for acid mine drainage treatment in co-digestion with vinasseGodoi, Leandro Augusto Gouvêa de 14 May 2018 (has links)
No presente trabalho foi avaliado o potencial do reator anaeróbio de leito fixo-estruturado e fluxo descendente (down-flow fixed strucutured bed reactor – DFSBR) para o tratamento de drenagens ácidas de minas (DAM) com vistas à recuperação de metais. Vinhaça de cana-de-açúcar foi utilizada como doador de elétrons para bactérias redutoras de sulfato (BRS) e ferro (Fe2+) foi adicionado como metal de referência. Em associação com a sulfetogênese, produção de metano foi promovida pela relação DQO/SO42- de 2,0, maior que a relação estequiométrica de oxidação da matéria orgânica via redução de SO42- (0,67). Concentrações afluentes de DQO e SO42- da ordem de 4000 mg.L-1 e 2000 mg.L-1, respectivamente, foram mantidas durante todo o período experimental (547 dias), sendo o reator operado com TDH de 20 h. Durante a ETAPA 1 (277 dias) o DFSBR foi alimentado com substrato sintético simulando a fração solúvel da vinhaça e recebeu cargas crescentes de ferro (0,07 a 0,51 g Fe2+.L-1.d-1) para avaliação do potencial de remoção de metais. Foram obtidas eficiências de remoção de DQO e SO42- de 94±2% e 97±3%, respectivamente. Remoção de ferro de 95±5% foi alcançada, assim como proporções crescentes de ferro (de até 55%) nas cinzas do precipitado. Ao longo da ETAPA 2 (100 dias) vinhaça foi utilizada como único doador de elétrons e diferentes razões de recirculação foram estudadas (0, 50, 100 e 150 vezes), com velocidades superficiais do escoamento variando de 0,03 a 5,20 m.h-1. A eficiência de remoção de DQO de 82±6% foi atribuída à presença de compostos recalcitrantes na vinhaça, ao passo que a remoção de SO42- permaneceu próxima da alcançada na ETAPA 1 (95±5%). Uma produção volumétrica de metano da ordem de 390 mL CH4.L-1.d-1 foi obtida (CNTP). A despeito da variação nas taxas de reciclo, maior estabilidade e eficiência de remoção de ferro (96±3%) foram determinadas na ausência de recirculação, com ganhos econômicos para o processo. Durante a ETAPA 3 (170 dias) a diminuição gradativa do pH afluente de 6,30 para 3,50 foi realizada. Apesar da supressão de alcalinidade, o sistema atingiu eficiências de remoção de SO42- de 97±1% e remoção de ferro de 95±4%. Foram observados efeitos adversos sobre o metabolismo metanogênico, com queda na produção de metano de 380 para 230 mL CH4.L-1.d-1, acompanhada por aumento da DQO residual no efluente (1500 mg DQO.L-1). Ainda assim, o DSFBR foi capaz de elevar o pH da água residuária de 3,5 para 6,9, confirmando o potencial do sistema para a neutralização de DAM. A caracterização da comunidade microbiana por análise do sequenciamento do gene RNAr 16S indicou predominância dos gêneros Desulfovibrio e Methanosaeta, comprovando o estabelecimento simultâneo dos processos sulfetogênicos e metanogênicos. Por fim, os resultados apontaram perspectivas promissoras de aplicação do DFSBR ao tratamento de DAM via redução de SO42- favorecendo a precipitação e separação de metais em reator de único estágio. A vinhaça de cana-de-açúcar também se mostrou um adequado doador de elétrons para o processo. / This work evaluated the potential of the down-flow fixed-structured bed anaerobic reactor (DFSBR) for the treatment of acid mine drainage (AMD) aiming at metals recovery. Sugarcane vinasse was used as electron donor for sulfate-reducing bacteria (BRS) and iron (Fe2+) was added as reference metal. In association with sulfidogenesis, methane production was promoted by the applied COD/SO42- ratio of 2.0, which is higher than the stoichiometric ratio for organic matter oxidation solely by SO42- reduction (0.67). Affluent concentrations of COD and SO42- were kept close to 4000 mg.L-1 and 2000 mg.L-1, respectively, over the entire experimental time (547 days). The reactor was operated with HRT of 20 h. During STAGE 1 (277 days) the DFSBR was fed with synthetic substrate simulating the soluble fraction of vinasse and received increasing iron loads (0.07 to 0.51 g Fe2+.L-1.d-1) to verify the potential for metal removal. COD and SO42- removal efficiencies were 94±2% and 97±3%, respectively. Iron removal of 95±5% was achieved, as well as increasing proportions of iron (up to 55%) were observed in the ashes of precipitate. Throughout STAGE 2 (100 days) sugarcane vinasse was used as unique electron donor whereas different recirculation ratios were studied (0, 50, 100 and 150 times), with superficial flow velocities ranging from 0.03 to 5.20 m-1. COD removal efficiency of 82±6% was attributed to the presence of recalcitrant compounds in the vinasse, while the removal of SO42- remained close to that previously achieved during STAGE 1 (95±5%). Volumetric methane production near of 390 mL CH4.L-1.d-1 was obtained (STP). Although the variation in the recycle rates, greater stability and efficiency of iron removal (96±3%) were determined in the absence of recirculation, with economic gains for the process. During the STAGE 3 (170 days) gradual decrease of the pH affluent from 6.30 to 3.50 was performed. Despite the alkalinity suppression, the system achieved SO42- removal efficiencies of 97±1% and iron removal close to 95±4%. Adverse effects over methanogenic metabolism were observed once methane production decreased from 380 to 230 mL CH4.L-1.d-1, which was followed by a residual COD increase in the effluent (1500 mg COD.L-1). Nevertheless, the DSFBR was able to raise the pH of the wastewater from 3.5 to 6.9, indicating the potential of such system for AMD neutralization. 16S rRNA gene sequencing analysis for microbial community characterization showed predominance of the genera Desulfovibrio and Methanosaeta, confirming the simultaneous establishment of sulfidogenic and methanogenic processes. Finally, the results presented promising perspectives for the DFSBR application to the AMD treatment via SO42- reduction, also favoring metals precipitation and separation in a single-stage reactor. Sugarcane vinasse was also considered a suitable electron donor for the process.
|
425 |
"Três formas de intervenção para a adesão ao tratamento dietético da obesidade em cardiologia: estudo comparativo" / Interventional actions directed to compliance with dietetic management in obesity and cardiology: comparative studyBruno, Maria Lucia Mendes 15 August 2006 (has links)
Trata-se de pesquisa realizada em hospital da rede pública estadual de São Paulo, especializado em cardiologia com pacientes obesos em acompanhamento ambulatorial pelo Serviço de Nutrição e Dietética (SND) dessa instituição. As formas de intervenção nutricional investigadas foram: atendimento individual, em grupo (controle) e grupo multiprofissional (com nutricionista e psicóloga). Na fase preliminar do estudo, realizou-se pesquisa de opinião que possibilitou o embasamento das variáveis analisadas. Na fase principal, os participantes foram divididos em grupos, sendo realizadas duas entrevistas individuais no intervalo de seis meses. Foram investigados apenas os pacientes de alta. Compararam-se os resultados obtidos quanto ao peso corporal, índice de massa corpórea, circunferência do abdome; o acompanhamento dos fatores de risco cardiovascular (hipertensão arterial, diabetes melito, dislipidemias) foi feito através da variação das medidas de pressão arterial e níveis sanguíneos de glicose, triglicérides, colesterol total e frações. Analisaram-se as opiniões sobre as facilidades e dificuldades para seguir as orientações recebidas por meio de instrumento próprio, não validado. No atendimento em grupo, foram obtidos resultados satisfatórios, porém não ideais, e verificou-se que os participantes passaram a valorizar o apoio familiar. No atendimento individual, os participantes conseguiram maior redução da glicemia e triglicérides, porém isso não pode ser atribuído exclusivamente à dieta. No atendimento em grupo multiprofissional, houve mudança de comportamento com valorização desse tipo de atendimento. / The study was performed in a cardiology specialty hospital of Sao Paulo state public system with obese outpatients followed up by the Sector of Nutrition and Dietetics of the institution. Nutritional intervention actions that were assessed include: individual visit, group approach (control) and multiprofessional group (including dietitian and psychologist). In the preliminary phase of the study, an opinion survey was performed, which supported many of the studied variables. In the main phase of the study, the participants were divided into groups, and 2 individual interviews were conducted within a 6-month interval. Only patients who had been discharged were assessed. The results concerning body weight, body mass index, abdominal circumference, and follow up of cardiovascular risks (arterial hypertension, diabetes mellitus, dyslipidemia) were compared using variation of blood pressure measures and blood levels of glucose, triglycerides and total and fractioned cholesterol. We also checked whether patients found it easy or difficult to follow the received instructions, using our own non-validated instrument. In the group activities, results were satisfactory but not optimal and participants started to value family support. In the individual approach, participants reached higher reduction of glucose and triglyceride levels, but they could not be explained exclusively by the diet. In the multiprofessional group, there was change in behavior and recognition of multiprofessional approach.
|
426 |
Caracterização de compostos de baixa massa molar redutores de ferro produzidos por fungos e mediação da reação de fenton para degradação de polissacarídeos e lignina / Characterization of low molecular weight Fe3+-reducing compounds produced by fungi and mediation of Fenton reaction to degrade polysaccharides and ligninValdeir Arantes 08 August 2008 (has links)
Os fungos de decomposição branca e parda produzem enzimas para degradar os componentes da madeira, os primeiros produzem enzimas hidrolíticas e oxidativas enquanto os outros produzem principalmente enzimas hidrolíticas. A degradação de polissacarídeos e lignina por fungos de decomposição parda e branca seletiva, respectivamente, não ocorre na região imediata à hifa, e, também, não pode ser explicada unicamente por ação enzimática devido a impermeabilidade das mesmas na parede celular. Neste trabalho estudou-se o sistema degradativo não enzimático envolvendo compostos de baixa massa molar (CBMM) redutores de ferro em fungos degradadores de madeira. O fungo de decomposição parda, Wolfiporia cocos e o de decomposição branca seletiva, Perenniporia medulla-panis foram cultivados em diferentes concentrações de ferro, e a atividade redutora de Fe3+ micelial e a extracelular, assim como a produção de quelantes específicos de ferro, como derivados de ácido hidroxâmico e de catecol, foram induzidas em condição de deficiência de ferro. Os géis de SDS-PAGE dos extratos fúngicos mostraram várias proteínas negativamente reguladas por ferro em P. medulla-panis e W. cocos, principalmente para proteínas entre 10 - 30 kDa. Quando os fungos foram cultivados em diferentes fontes de carbono simples com e sem suplementação de celulose microcristalina e deficiência de ferro, produziram CBMM redutores de Fe3+, os quais tiveram a produção estimulada nos meios com celulose. Análises de eletroforese capilar dos compostos quelantes de metal extraídos dos meios que proporcionaram a maior atividade redutora (Lornitina/ celulose para P. medulla-panis e glicose/celulose para W. cocos) na presença e ausência de ferro, confirmaram que, principalmente P. medulla-panis produz compostos extracelulares que são regulados por ferro. Os CBMM purificados das frações < 5 kDa apresentaram atividade redutora de Fe3+ em pH 2,0 mesmo quando ácido oxálico foi adicionado na concentração 20 vezes maior que a concentração de Fe3+. Em pH 4,5, a atividade redutora foi detectada até uma concentração de ácido oxálico 10 vezes superior a de Fe3+. Em ambos os casos a atividade redutora foi observada quando Fe3+ estava presente na forma livre ou complexada como Fe(oxalato)+. Dentre os vários CBMM produzidos por P. medulla-panis e W. cocos aqueles com atividade redutora foram o ácido 4-hidroxi-fenilacético, 1,2-dihidroxi-3-metil-benzeno, 1,2,3-trihidroxi-benzeno e o ácido 4- hidroxi-cinâmico para W. cocos, e para P. medulla-panis os principais foram 1,2-dihidroxibenzeno e 1,2,3-trihidroxi-benzeno. Além desses compostos, ambos os fungos produziram peptídeos de baixa massa molar com atividade redutora. Os CBMM redutores de Fe3+ de P. medulla-panis (Pmp) e de W. cocos (Wc) foram utilizados na ausência e presença de Fe3+ e H2O2 (reação de Fenton mediada) para oxidar polissacarídeos e lignina in vitro. Verificou-se que os maiores níveis de oxidação foram obtidos nas reações de Fenton mediadas (Wc-Fe3+/H2O2 e Pmp-Fe3+/H2O2). A degradação da celulose por estes sistemas foi caracterizada por uma rápida e extensiva despolimerização, seguida de significativa oxidação. Análises dos monômeros de lignina liberados de conífera tratada e não tratada após 13C-TMAH termoquimólise indicaram oxidação da lignina pelos sistemas Wc-Fe3+/H2O2 e Pmp- Fe3+/H2O2, principalmente por desmetoxilação e/ou desmetilação. A ação sinérgica entre os CBMM redutores de Fe3+ e as enzimas ligninolíticas ficou evidenciada para os fungos de decomposição branca Lentinula edodes, P. medulla-panis e Trametes versicolor através da oxidação do corante Azure B. / Brown and white rot fungi produce enzymes to degrade wood. The former produce hydrolytic and oxidative enzymes while the latter produce mainly hydrolytic enzymes. The degradation of polysaccharides and lignin by brown and white-rot fungi, respectively, do not occur next to the fungal hyphae and cannot be explained only by the enzymatic action due to the small pore size of sound wood. In this work, it was studied a non-enzymatic degradative system involving low molecular weight compounds (LMWC) with Fe3+-reducing activity in wood decay fungi. The brown rot fungus Wolfiporia cocos and the selective white rot Perenniporia medulla-panis were grown under varying concentration of iron. The micelial and extracellular Fe3+-reducing activity as well as the production of specific iron chelators (catechol and hydroxamate derivatives) were induced under iron starvation. SDS-PAGE gels of cellular proteins showed several proteins negatively iron-regulated in P. medulla-panis and in W. cocos, especially for proteins of 10 - 30 kDa. When the fungi were grown with different simple carbon source with and without microcrystalline cellulose supplementation and under iron restriction, they produced LMWC with Fe3+-reducing activity, which production was stimulated in the presence of cellulose. Capillary electrophoresis analyses of metal chelating compounds extracted from the growth media that promoted the highest Fe3+-reducing activity (L-ornithine/cellulose for P. medulla-panis and glucose/cellulose for W. cocos) in the presence and absence of iron, confirmed that, especially P. medulla-panis produces extracellular compounds that are iron-regulated. LMWC purified from these media showed Fe3+-reducing activity at pH 2.0 even when oxalic acid was added up to 20 fold the iron concentration. At pH 4.5, the Fe3+-reducing activity was detected at an oxalic acid concentration up to 10 fold the iron concentration. In both cases the LMWC were capable of reducing Fe3+ only when it was in its free form or complexed with oxalate to form Fe3+-monooxalate complex (Fe(C2O4)+). Among the several LMWC produced by P. medulla-panis and W. cocos those with Fe3+-reducing capability were 4-hydroxy-phenylacetic acid, 1,2- dihydroxy-methyl-benzene, 1,2,3-trihydroxy-benzene and 4-hydroxy-cinnamic acid to W. cocos and 1,2-dihydroxy-benzene, and 1,2,3-tri-hydroxy-benzene to P. medulla-panis. Both fungi also produce low molecular weight peptides with Fe3+-reducing capability. The purified LMWC with Fe3+-reducing activity from P. medulla-panis (Pmp) and from W. cocos (Wc) were utilized in the presence and absence of Fe3+ and H2O2 (mediated Fenton reaction) to oxidize polysaccharides and lignin in vitro. The highest oxidation levels were obtained with mediated Fenton reactions (Wc-Fe3+/H2O2 e Pmp-Fe3+/H2O2). Cellulose degradation by these systems was characterized by a rapid and extensive depolymerization followed by significant oxidation. Analyses of the lignin monomers released from treated and untreated softwood after 13C-TMAH thermochemolysis indicated lignin oxidation by the Wc-Fe3+/H2O2 and Pmp-Fe3+/H2O2 systems, mainly by demethoxylation and/or demethylation. The synergistic action between LMWC with Fe3+-reducing activity and the ligninolytic enzymes was evidenced to the white rot fungi Lentinula edodes, P. medulla-panis and Trametes versicolor with Azure B oxidation assays.
|
427 |
Caracterização microbiana e remoção do alquilbenzeno linear sulfonado em reator EGSB / Microbial characterization and removal of linear alkylbenzene sulfonate in EGSB reactorDelforno, Tiago Palladino 18 March 2011 (has links)
O presente trabalho teve por objetivo avaliar a eficiência de remoção do surfactante aniônico alquilbenzeno linear sulfonado (LAS) em reator anaeróbio de leito granular expandido - EGSB (1,5 litros) com recirculação e alimentação com meio mineral. Além de caracterizar filogeneticamente a diversidade de bactérias na presença do surfactante. O sistema foi operado em condição mesofílica em 4 etapas: (I), (II) e (IV) com TDH de 32 horas, e (III) com TDH de 26 horas. Em todas as etapas a DQO foi em média de 609 \'+ OU -\' 137 mg/L e 14 \'+ OU -\' 1,71 mg/L de LAS afluente. As maiores remoções de LAS foram verificada nas etapas II e IV, com valores de 73,6 \'+ OU -\' 5,6% e 63,6 \'+ OU -\' 6,17%, respectivamente de. Na etapa III essa remoção foi de 47,8 \'+ OU -\' 6,2%. Por meio do balanço de massa constatou-se que 56,6% do total de LAS adicionado foram removidos compreendendo 48,4% por biodegradação e 8,2% por adsorção. A remoção de matéria orgânica não foi afetada com a adição do LAS e nem pela exposição prolongada a esse surfactante. Entretanto, a estrutura do grânulo foi comprometida quando da adição do surfactante, observado pelo aumento da concentração de sólidos totais efluente de 0,049 g/L na etapa I (sem LAS), 0,128 g/L na etapa II, 0,064 g/L na etapa III e 0,038 g/L na etapa IV, quando da adição de 14 \'+ OU -\' 1,71 mg LAS/L. Além disso, foi notada diminuição do diâmetro médio dos grânulos no decorrer da operação do reator de 0,36 cm nas etapas I e III para 0,34 cm na etapa IV. Por meio da técnica de tubos múltiplos (NMP) foi constatado aumento das bactérias anaeróbias totais e diminuição das arqueias metanogênicas, em função do tempo de operação do reator. As bactérias redutoras de ferro representaram 8% da biomassa anaeróbia na etapa IV. Por meio do seqüenciamento da região 16S do RNAr para o domínio Bacteria da biomassa da extremidade superior do reator e da biomassa do leito, foi verificado semelhança com os seguintes filos Proteobacteria, Firmicutes e Synergistetes. Notou-se diferença significativa entre as bibliotecas de clones para essas duas amostras. / This study aimed to evaluate the efficiency of removal of linear alkylbenzene sulfonate (LAS) in expanded bed reactor (1.5 liters) using granular sludge (EGSB) with recirculation and feed with mineral medium modified. The system was operated at mesophilic condition in four stages: (I) (II) and (IV) with HRT of 32 hours, and (III) with HRT of 26 hours. At all stages the COD averaged 609 \'+ OR -\' 137 mg/L and 14 \'+ OR -\' 1.71 mg/L LAS influent. The higher removals of LAS were found in stages II and IV, respectively, 73.6 \'+ OR -\' 5.6% and 63.6 \'+ OR -\' 6.17%. In stage III this removal was 47.8 \'+ OR -\' 6.2%. Through mass balance was found that 56.6% of total LAS added were removed by biodegradation comprising 48.4% and 8.2% by adsorption. The organic matter removal was not affected by the addition of LAS and not by prolonged exposure to this surfactant. However, the granule structure was compromised after the addition of surfactant, the observed increase in effluent total solids concentration of 0.049 g/L in stage I (no LAS), 0.128 g/L in stage II, 0.064 g/L in stage III and 0.038 g/L in stage IV when adding 14 \'+ OR -\' 1.71 mg/L. Furthermore, it was noticed significant decrease in mean diameter of the granules during the operation of the reactor of 0.36 cm in stages I and III to 0.34 cm in stage IV. Through the multiple tube method (MPN) was found to increase the total anaerobic bacteria and methanogenic archaea decreased depending on the time of reactor operation. Iron-reducing bacteria accounted for 8% of anaerobic bacteria total in step IV. By sequencing the 16S rRNA for the domain Bacteria biomass from the upper end of the reactor and the biomass of the bed, was found similar to the following phyla Proteobacteria, Firmicutes and Synergistetes. Significant difference was noted between the clone libraries for these two samples.
|
428 |
Production et élimination des sulfures produits lors de la biométhanisation de boues de station de traitement des eaux usées domestiques : Procédés biologiques de sulfooxydation par des thiobacilles anaérobies facultatifs (projet SULFOX) / Production and removal of sulfides produced during biomethanation of from domestic wastewater treatment plant sludge : Biological sulfooxidation processes using facultative anaerobic thiobacilli (SULFOX project)El Houari, Abdelaziz 30 August 2018 (has links)
Reconnu par leur effet toxique, inhibiteur et corrosif, les sulfures (S2-, SH-, SH2) sont un sous-produit indésirable de la digestion anaérobie des boues de station de traitement des eaux domestiques de la ville de Marrakech, Maroc (STEP). Ils proviennent essentiellement de la réduction "dissimilatrice" des composés soufrés (SO4 2-, SO3 2-, S2O4 2- ..) contenus dans ces boues. Ce processus est réalisé par un groupe bactérien anaérobie appelé bactéries sulfatoréductrices (BSR). Une fois dans le biogaz, les sulfures sous forme gazeuse réduisent en plus la durée de vie des installations et des équipements de la STEP. Elle est ainsi dotée d’installations biologiques et physico-chimiques lui permettant d’éliminer ces sulfures avant la transformation du biogaz en énergie électrique. Cependant, ces procédés sont onéreuses et grandes consommatrices d’énergies. D’où l’idée de minimiser la production des sulfures au sein même des digesteurs anaérobies. Pour cela, il était nécessaire d’abord de connaître les microorganismes à l'origine de la production des sulfures (BSR), ceux potentiellement impliqués dans leur élimination (bactéries sulfo-oxydantes), et d’un groupe de microorganismes fermentaires (Synergistetes) intervenant dans le bon fonctionnement de la digestion anaérobie. Ces études ont été menées à la fois sur des d'approches moléculaires et culturales. Les résultats obtenus, ont permis de comprendre comment ces groupes bactériens, d’intérêts écologique et économique importants, interviennent dans la digestion anaérobie des boues de la STEP permettant à la fois d’accélérer les processus d’oxydation de la matière organique combinée à la réduction des composés soufrés et de minimiser la concentration des en sulfure dans le biogaz. / Recognized by their toxic, inhibitory and corrosive effect, sulfides (S2-, SH-, H2S) are an undesirable by-product of the anaerobic digestion of from domestic wastewater treatment plants sludge in the city of Marrakech, Morocco (WWTP). They produced mainly by the dissimilatory reduction of sulfur compounds (SO42-, SO32-, S2O42-) contained in these sludges. This process is performed by an anaerobic bacterial group called sulfate reducing bacteria (SRB). Once in the biogas, the sulfides in gaseous form shorten in addition the lifetime of the installations and equipments of the WWTP. It is thus equipped with biological and physicochemical installations allowing it to eliminate these sulfides before the transformation of biogas into electrical energy. However, these processes are expensive and consume large amounts of energy. Hence the idea of minimizing the production of sulfides within anaerobic digesters. For this, it was first necessary to know the microorganisms originating of the production of sulfides (SRB), those potentially involved in their elimination (sulfur oxidizing bacteria), and a group of fermentative microorganisms (Synergistetes) involved in the good functioning of the anaerobic digestion. These studies were conducted on both molecular and cultural approaches. The results obtained allowed to understand how these bacterial groups, of great ecological and economic interest, are involved in the anaerobic digestion of sludge from the WWTP, which both accelerates the oxidation processes of the organic matter combined with the reduction of sulfur compounds and to minimize the concentration of sulfide in biogas.
|
429 |
Spéciation isotopique et moléculaire du mercure dans les environnements aquatiques influencée par des processus biotiques et abiotiques / Influence of biotic and abiotic processes on mercury isotopic and molecular speciation in aquatic environmentsPerrot, Vincent 10 February 2012 (has links)
Le mercure (Hg) est un métal lourd ubiquiste et très toxique. Présent à l’état de traces dans la colonne d’eau des milieux aquatiques, il peut cependant atteindre des concentrations très élevées en fin de chaine alimentaire car il a la particularité d’être bioaccumulé et bioamplifié dans les organismes sous forme de méthylmercure (MeHg). L’identification et la caractérisation des transformations amenant à la formation de MeHg (méthylation) ou à sa dégradation (déméthylation) sont donc de première importance pour évaluer son devenir dans les milieux aquatiques. L’utilisation du comportement des isotopes stables du Hg, à la fois en laboratoire mais aussi dans des échantillons environnementaux, a permis d’évaluer l’influence des processus biotiques et abiotiques mis en jeu dans les système aquatiques sur les transformations et donc la spéciation du Hg dans de tels environnements. Le fractionnement isotopique du Hg, pouvant être dépendant et/ou indépendant de la masse, s’est également avéré être un outil performant pour étudier sa bioaccumulation dans plusieurs membres de la chaîne alimentaire endémique du Lac Baikal (Russie). Les signatures isotopiques mesurées dans ces échantillons ont permi d’améliorer la connaissance sur la distribution, les sources et les transformations affectant les espèces du Hg dans l’écosystème de ce grand lac faisant partie du patrimoine mondial de l’UNESCO depuis 1996 et étant la plus grande réserve d’eau douce liquide de surface mondiale. / Mercury (Hg) is a toxic and ubiquitous heavy metal. Only present at trace levels in the water column of aquatic systems, it can reach high amounts in food web end-members because of its ability to bioaccumulate and biomagnify in organisms as methylmercury (MeHg). Hence, the characterization of the transformations leading to the formation (methylation) and the degradation (demethylation) of MeHg is of great concern to evaluate its fate in aquatic environments. The use of the Hg stable isotopes, during laboratory experiments or in environmental samples, allowed to identify and characterize several biotic and biotic pathways involved in Hg transformations and speciation in aquatic systems. The study of Hg mass-dependent and/or mass-independent fractionation was also a competitive tool to assess its bioaccumulation process in several members of the Lake Baikal endemic food chain (Russia). Measured Hg isotopic signatures in such samples provided insight about Hg species fate and sources within the ecosystem of this lake, which has been nominated as a world heritage site by UNESCO in 1996 and constitutes the world’s largest freshwater lake in terms of volume.
|
430 |
Structure et fonctionnement de tapis microbiens contaminés par des hydrocarbures / Structure and functioning of hydrocarbon polluted microbial matsAubé, Johanne 05 November 2014 (has links)
Ubiquitaires et très anciens, les communautés des tapis microbiens font preuve de capacités métaboliques et adaptatives très importantes. Situés en zone côtières, ces écosystèmes peuvent être soumis à des contaminations pétrolières. Dans ce contexte, cette étude vise d’une part à décrire la structure et le fonctionnement de tapis microbiens et d’autre part à comprendre l’impact d’une contamination pétrolière sur ces écosystèmes. Cette étude porte sur deux tapis microbiens de l’étang de Berre aux paramètres physico-Chimiques proches mais présentant des contaminations pétrolières contrastées. Le fonctionnement du système étant tributaire d’autres facteurs tels que la lumière et les saisons, les variations saisonnières et nycthémérales ont été prises en compte dans cette étude. Un accent particulier a également été porté sur le cycle du soufre de par son importance en milieu marin. Les résultats de cette étude mettent en évidence des structures de communautés différentes entre les deux tapis au niveau global, la séparation spatiale prévalant sur la séparation saisonnière. La fraction active de la communauté du site contaminé présente une évolution linéaire tandis que celle du site témoins suit pour sa part les variations saisonnières. Au niveau du site contaminé une augmentation de l’expression des gènes impliqués dans la dégradation des hydrocarbures couplée à une biodégradation des hydrocarbures suggère que le tapis contaminé est adapté à la contamination pétrolière. Malgré les différences de structures et d’activités de dégradation, des profils métaboliques très semblables sont cependant observables entre les deux tapis, avec des fonctions similaires laissant supposer une redondance fonctionnelle. Des variations saisonnières et nycthémérales ont également été observées avec notamment des Desulfobulbaceae plus abondantes au printemps et plus actives en journée. Des études culturales ont été réalisées en parallèle. Elles permettront d’appréhender de manière complémentaire la dynamique des communautés des sulfato-Réducteurs au sein du tapis et de mieux comprendre les variations mises en évidence dans cette étude. / Ubiquist and very ancient, the microbial mats communities demonstrate very important metabolic and adaptive capacities. Located in the coastal area, these ecosystems may be subject to oil contamination. In this context, the aim of this study is on one hand to describe the structure and functioning of microbial mats and on the other to understand the impact of oil contamination on these ecosystems. This study focused on two microbial mats from the Berre lagoon with close physical chemical parameters but with contrasted hydrocarbon contamination levels. The functioning of the system is dependent on other factors such as light and seasons, diurnal and seasonal variations were taken into account in this study. Special emphasis was placed on the sulfur cycle due to its importance in the marine environments. The results of this study highlighted different communities’ structures at the global level between both mats, the spatial variation prevailed on seasonal variation. The active part of the community from the contaminated site shows a linear trend while that one of the uncontaminated site follows the seasonal variations. The contaminated site shows genes involved in hydrocarbon degradation more expressed coupled to a hydrocarbon biodegradation suggesting that the contaminated mat is adapted to the petroleum contamination. Despite these differences in the structure and the degradation capacities, very similar metabolic profiles are observed between the two mats with similar functions, suggesting functional redundancy. Seasonal and diurnal variation was also observed, the Desulfobulbaceae were particularly more abundant in spring and more active during the day. A complementary cultural approach will allow to better understanding the dynamics of sulfate-Reducers communities in the mat and comprehending these variations.
|
Page generated in 0.0718 seconds