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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.
1

Biorremediação de solo tropical contaminado com resíduos da produção de plastificantes. / Bioremediation of a tropical soil contaminated with plasticizers process wastes.

Ferreira, Ieda Domingues 10 February 2009 (has links)
Plastificantes podem ser definidos como aditivos de baixa volatilidade utilizados para aumentar a processabilidade, flexibilidade ou diminuir a dureza de materiais poliméricos. Os ftalatos e adipatos utilizados como plastificantes, por sua baixa solubilidade em água e pelo alto coeficiente de partição octanol/água, tendem a se acumular no solo e sedimentos. Estes compostos são considerados potencialmente carcinogênicos, teratogênicos e disruptores endócrinos. A presente pesquisa compreendeu a biorremediação ex-situ do solo contaminado com resíduos de uma unidade industrial de plastificantes, utilizando reatores aeróbios, com microrganismos indígenas e exógenos adaptados através da adição de inóculo retirado da Estação de Tratamento de Efluentes por Lodos Ativados desta indústria. Foram avaliados os plastificantes: DIBP (Di-isobutilftalato), DBP (Dibutilftalato), DOP (Dioctilftalato),DIDP (Di-isodecilftalato), DIAP (Di-isoamilftalato) e DOA (dioctiladipato). Após a caracterização geotécnica do solo da área de plastificantes em 10 diferentes pontos, foram retiradas as quantidades para a biorremediação em 8 diferentes pontos (100kg/ponto) com os teores totais de plastificantes compreendidos entre 17 mg/kg solo a 6222 mg/kg solo. Análises mineralógicas, físicas e químicas foram realizadas posteriormente e indicaram que possivelmente a capacidade de troca catiônica do solo era devida aos plastificantes. Na biorremediação, os teores iniciais de plastificantes no solo, variaram de 85 mg/kg a 1688 mg/kg e após 120 dias de biodegradação em reatores aeróbios, as eficiências de remoção foram de 75 a 97%. Conforme as análises de fingerprint da comunidade bacteriana, ao final do processo, as bactérias presentes no solo eram originárias do lodo e do solo inicial e as análises de CGMS identificaram os metabólitos MEHP e os sub-produtos finais da biodegradação. / Plasticizers are low volatility compounds that offer flexibility and processability to resins. The phthalates and adipates, used as plasticizers, have low water solubility e high partition octanol/water(Kow) and accumulate in soil and sediments. This compounds are considered teratogenics, carcinogenics and as endocrine disruptors. This study evaluated the bioremediation of tropical soil contaminated with plasticizers process wastes, in aerobic conditions, with and without introduction of acclimated bacteria. After geological analysis of soil, considering ten differents points on the factory area, it was selected the soil for biodegradation of eight points (100kg/point) representing 17mg total plasticizers/kg soil to 6222mg total plasticizers/kg soil. Mineralogical, physical and chemical analysis were done and the results showed that perhaps the cationic change capacity was due to plasticizers. The plasticizers contents in soil were 85-1688mg/kg and after 120 days of biodegradation in eight aerobic reactors, the removal efficiencies were 75-97%. The fingerprint analysis showed that the final bacteria present in reactors originated from soil and sludge and the CGMS analysis identified the metabolic MEHP, and showed the sub-products and final products of biodegradation.
2

Biorremediação de solo tropical contaminado com resíduos da produção de plastificantes. / Bioremediation of a tropical soil contaminated with plasticizers process wastes.

Ieda Domingues Ferreira 10 February 2009 (has links)
Plastificantes podem ser definidos como aditivos de baixa volatilidade utilizados para aumentar a processabilidade, flexibilidade ou diminuir a dureza de materiais poliméricos. Os ftalatos e adipatos utilizados como plastificantes, por sua baixa solubilidade em água e pelo alto coeficiente de partição octanol/água, tendem a se acumular no solo e sedimentos. Estes compostos são considerados potencialmente carcinogênicos, teratogênicos e disruptores endócrinos. A presente pesquisa compreendeu a biorremediação ex-situ do solo contaminado com resíduos de uma unidade industrial de plastificantes, utilizando reatores aeróbios, com microrganismos indígenas e exógenos adaptados através da adição de inóculo retirado da Estação de Tratamento de Efluentes por Lodos Ativados desta indústria. Foram avaliados os plastificantes: DIBP (Di-isobutilftalato), DBP (Dibutilftalato), DOP (Dioctilftalato),DIDP (Di-isodecilftalato), DIAP (Di-isoamilftalato) e DOA (dioctiladipato). Após a caracterização geotécnica do solo da área de plastificantes em 10 diferentes pontos, foram retiradas as quantidades para a biorremediação em 8 diferentes pontos (100kg/ponto) com os teores totais de plastificantes compreendidos entre 17 mg/kg solo a 6222 mg/kg solo. Análises mineralógicas, físicas e químicas foram realizadas posteriormente e indicaram que possivelmente a capacidade de troca catiônica do solo era devida aos plastificantes. Na biorremediação, os teores iniciais de plastificantes no solo, variaram de 85 mg/kg a 1688 mg/kg e após 120 dias de biodegradação em reatores aeróbios, as eficiências de remoção foram de 75 a 97%. Conforme as análises de fingerprint da comunidade bacteriana, ao final do processo, as bactérias presentes no solo eram originárias do lodo e do solo inicial e as análises de CGMS identificaram os metabólitos MEHP e os sub-produtos finais da biodegradação. / Plasticizers are low volatility compounds that offer flexibility and processability to resins. The phthalates and adipates, used as plasticizers, have low water solubility e high partition octanol/water(Kow) and accumulate in soil and sediments. This compounds are considered teratogenics, carcinogenics and as endocrine disruptors. This study evaluated the bioremediation of tropical soil contaminated with plasticizers process wastes, in aerobic conditions, with and without introduction of acclimated bacteria. After geological analysis of soil, considering ten differents points on the factory area, it was selected the soil for biodegradation of eight points (100kg/point) representing 17mg total plasticizers/kg soil to 6222mg total plasticizers/kg soil. Mineralogical, physical and chemical analysis were done and the results showed that perhaps the cationic change capacity was due to plasticizers. The plasticizers contents in soil were 85-1688mg/kg and after 120 days of biodegradation in eight aerobic reactors, the removal efficiencies were 75-97%. The fingerprint analysis showed that the final bacteria present in reactors originated from soil and sludge and the CGMS analysis identified the metabolic MEHP, and showed the sub-products and final products of biodegradation.
3

Isolamento e caracterização de bactérias degradadoras de acefato. / Isolation and characterization of acephate degrading bacteria.

Góes, Karina Paschoal 29 May 2009 (has links)
Quatro linhagens capazes de crescer com acefato foram isoladas a partir de solos com históricos de aplicação de deste composto. Stenotrophomonas maltophilia, Rhodococcus sp., Staphylococcus sp. e Pandoreae sp. foram identificadas através do rDNA 16S e perfil de ácidos graxos de membrana. Rhodococcus sp. foi o isolado mais eficiente na degradação de acefato, removendo 99.24% deste composto em meio de cultura com acefato como única fonte de carbono. Quando avaliado com acefato como fonte combinada de carbono e nitrogênio, este organismo degradou 19% de acefato com formação de metamidofós (17%). Staphylococcus sp. apresentou 21% de degradação de acefato utilizando-o como fonte de carbono e nitrogênio, mas não manteve o crescimento com este composto como fonte de carbono. Stenotrophomonas maltophilia e Pandoreae sp. não mantiveram crescimento com acefato como única fonte de carbono isoladamente. Estas linhagens apresentaram crescimento em acefato como fonte de nitrogênio e enxofre, porém, as análises de GC/MS demonstraram que não houve degradação nestas condições. / Four strains of microorganisms capable of growth on acephate were isolated from soil samples with a history of acephate application. Stenotrophomonas maltophilia, Rhodococcus sp., Staphylococcus sp. and Pandoreae sp. were identified based on 16S rRNA gene sequencing and fatty acid profiling. Rhodococcus sp. was the most efficient acephate degrader of the isolates, it removed 99.24% of acephate from defined growth media when the compound was provided as sole carbon source. When provided as a combined carbon and nitrogen source, the organisms degraded 19% of acephate with formation of methamidophos (17%). Staphylococcus sp. degraded 21% of acephate when provided as sole nitrogen and carbon source but did not grow on the compound as a sole source of carbon. Pandoreae sp. and Stenotrophomonas maltophilia failed to grow on acephate as sole source of carbon in defined medium. These strains grew in media where the pesticide was provided as a combined nitrogen and carbon source, but no acephate biodegradation could be demonstrated in these instances.
4

Análise econômica da produção de polímeros biodegradáveis no contexto de uma biorefinaria a partir de cana-de-açúcar. / Economic assessment of biopolymer production in a sugarcane based biorefinery context.

Raicher, Gil 05 September 2011 (has links)
Polihidroxialcanoatos são polímeros biodegradáveis, sintetizados por bactérias a partir de fontes de carbono renováveis. Este trabalho se concentra na produção de P3HB a partir de xilose no contexto de uma usina padrão de álcool e açúcar que produz energia através de cogeração, utiliza resíduos agrícolas de cana-de-açúcar e passaria a produzir etanol de segunda geração a partir do bagaço. A produção de PHAs a partir de xilose, hoje descartada, poderá viabilizar a geração de etanol de segunda geração. Variou-se a produtividade (0,28 e 1,11 g/L.h), o preço (R$ 4,50 R$ 9,00), o custo do fermentador (três cenários entre US$ 475 - 3.013 mil) e a capacidade produtiva da planta (dez cenários de 1.000 a 35.000 mil t/ano). As visões de resultado oferecem a margem de contribuição, lucratividade líquida da operação, bem como o ponto de breakeven. Recomenda-se redirecionar parte dos esforços de pesquisa voltados a um aumento do teor de P3HB na célula para a melhoria da produtividade do processo, que é o fator-chave para que o processo se torne economicamente mais atrativo. / Polyihydroxyalkanoates are biodegradable polymers, synthetized by bacteria from renewable sources of carbon. This thesis focuses on production of P3HB from xylose in the context of a standard sugar and ethanol plant, cogenerates steam and electrical energy utilizing sugarcane bagasse and agricultural residues. PHAs production from xylose, discarded in most mills nowadays, may enable profitability of 2nd generation bioethanol. Productivity varied from 0,28 to 1,11 g/L.h, and PHB price ranged from R$ 4,50 to R$ 9,00 per kilo. Fermentor cost was studied in 3 scenarios from US$ 475 to 3.013 thousand and the production capacity was analyzed in ten different scenarios, from 1,000 to 35,000 thousand tonnes/year. Result reviews offer contribution margin, net operational profit, as well as breakeven point analysis. Recommended is to redirect part of the research efforts from improving P3HB yields to process productivity improvement, which turned out to be the key factor to economic feasibility.
5

Análise econômica da produção de polímeros biodegradáveis no contexto de uma biorefinaria a partir de cana-de-açúcar. / Economic assessment of biopolymer production in a sugarcane based biorefinery context.

Gil Raicher 05 September 2011 (has links)
Polihidroxialcanoatos são polímeros biodegradáveis, sintetizados por bactérias a partir de fontes de carbono renováveis. Este trabalho se concentra na produção de P3HB a partir de xilose no contexto de uma usina padrão de álcool e açúcar que produz energia através de cogeração, utiliza resíduos agrícolas de cana-de-açúcar e passaria a produzir etanol de segunda geração a partir do bagaço. A produção de PHAs a partir de xilose, hoje descartada, poderá viabilizar a geração de etanol de segunda geração. Variou-se a produtividade (0,28 e 1,11 g/L.h), o preço (R$ 4,50 R$ 9,00), o custo do fermentador (três cenários entre US$ 475 - 3.013 mil) e a capacidade produtiva da planta (dez cenários de 1.000 a 35.000 mil t/ano). As visões de resultado oferecem a margem de contribuição, lucratividade líquida da operação, bem como o ponto de breakeven. Recomenda-se redirecionar parte dos esforços de pesquisa voltados a um aumento do teor de P3HB na célula para a melhoria da produtividade do processo, que é o fator-chave para que o processo se torne economicamente mais atrativo. / Polyihydroxyalkanoates are biodegradable polymers, synthetized by bacteria from renewable sources of carbon. This thesis focuses on production of P3HB from xylose in the context of a standard sugar and ethanol plant, cogenerates steam and electrical energy utilizing sugarcane bagasse and agricultural residues. PHAs production from xylose, discarded in most mills nowadays, may enable profitability of 2nd generation bioethanol. Productivity varied from 0,28 to 1,11 g/L.h, and PHB price ranged from R$ 4,50 to R$ 9,00 per kilo. Fermentor cost was studied in 3 scenarios from US$ 475 to 3.013 thousand and the production capacity was analyzed in ten different scenarios, from 1,000 to 35,000 thousand tonnes/year. Result reviews offer contribution margin, net operational profit, as well as breakeven point analysis. Recommended is to redirect part of the research efforts from improving P3HB yields to process productivity improvement, which turned out to be the key factor to economic feasibility.
6

Isolamento e caracterização de bactérias degradadoras de acefato. / Isolation and characterization of acephate degrading bacteria.

Karina Paschoal Góes 29 May 2009 (has links)
Quatro linhagens capazes de crescer com acefato foram isoladas a partir de solos com históricos de aplicação de deste composto. Stenotrophomonas maltophilia, Rhodococcus sp., Staphylococcus sp. e Pandoreae sp. foram identificadas através do rDNA 16S e perfil de ácidos graxos de membrana. Rhodococcus sp. foi o isolado mais eficiente na degradação de acefato, removendo 99.24% deste composto em meio de cultura com acefato como única fonte de carbono. Quando avaliado com acefato como fonte combinada de carbono e nitrogênio, este organismo degradou 19% de acefato com formação de metamidofós (17%). Staphylococcus sp. apresentou 21% de degradação de acefato utilizando-o como fonte de carbono e nitrogênio, mas não manteve o crescimento com este composto como fonte de carbono. Stenotrophomonas maltophilia e Pandoreae sp. não mantiveram crescimento com acefato como única fonte de carbono isoladamente. Estas linhagens apresentaram crescimento em acefato como fonte de nitrogênio e enxofre, porém, as análises de GC/MS demonstraram que não houve degradação nestas condições. / Four strains of microorganisms capable of growth on acephate were isolated from soil samples with a history of acephate application. Stenotrophomonas maltophilia, Rhodococcus sp., Staphylococcus sp. and Pandoreae sp. were identified based on 16S rRNA gene sequencing and fatty acid profiling. Rhodococcus sp. was the most efficient acephate degrader of the isolates, it removed 99.24% of acephate from defined growth media when the compound was provided as sole carbon source. When provided as a combined carbon and nitrogen source, the organisms degraded 19% of acephate with formation of methamidophos (17%). Staphylococcus sp. degraded 21% of acephate when provided as sole nitrogen and carbon source but did not grow on the compound as a sole source of carbon. Pandoreae sp. and Stenotrophomonas maltophilia failed to grow on acephate as sole source of carbon in defined medium. These strains grew in media where the pesticide was provided as a combined nitrogen and carbon source, but no acephate biodegradation could be demonstrated in these instances.
7

Assessment of Environmental Issues And Biodegradation Aspects of Current MSW Practices of Developing Country Metropolises - A Case Study of Bangalore

Shwetmala, * January 2016 (has links) (PDF)
Municipal solid waste (MSW) production has significantly increased in the rapidly urbanizing developing world and also changed composition with increased decomposable organic fraction in MSW (OFMSW) and plastics content. This has stressed the environment in many ways while city managers and citizens have responded with various technological and management solutions leading to a need for scientific, environmental, technological and sustainability assessments of the emerging problems. This sets the research agenda and framework for this study wherein the MSW generation, composition, processing and treatment methods, open dumping practices, environmental liability, natural degradation, sustainability issues etc. have been studied for the city of Bangalore as a model for such an emerging problem. Results show that MSW generation ranged from 0.1-0.4 kg/person/day and the OFMSW content was >80% emerging predominantly from fruit, vegetable and food wastes. About 10-15% of daily MSW generated appeared to be haphazardly dumped around the city in ~700 small to large dumps ranging from 10-6,500 m2 with potential for large GHG emissions. Their spread and characteristics were assessed for 3 consecutive years using a novel rapid survey method developed at IISc involving motorcycle borne student volunteer teams, GPS enabled locating, physical measurements and satellite image interpretations. Results indicated that dump sites were of three types, ephemeral small sized in the core area (303) functioning as transfer stations, medium sized ones in outer areas that were closed rapidly with construction debris and very soon inhabited with dwellings and the larger and longer duration dumps (2-3 years, 393) in the peripheral regions within 10 km from the city administrative boundary. This method was compared with physical measurement and satellite imaging and gave very high level of accuracy and is hence suggested for other cities as well. A smaller fraction of MSW is also dumped in open drains that lead to choking and flooding of 3 locations and this was studied with some detail. The environmental footprint of such dumps were assessed by theoretical and experimental on-site and off-site approaches and experimental results show low GHG (CH4) emissions and emission factors that was largely attributable to the shallow depth of dumps (~0.7 m) and its low pH. The decomposition rates were experimentally determined for open dump sites and drivers for decomposition monitored. By providing differential access to macro-fauna, meso-micro organisms and only soil contact in field scale experiments it was determined that the greatest loss in weight occurred primarily due to the rapid drying process that brings down decomposition within 6 days. During the early stages of decomposition, mostly micro with meso organisms are responsible and after 6 days, the moisture content falls below 60% making microbiological decomposition difficult and enabling other foraging organisms to take over. The weight loss (decay) could be patterned both on exponential decay or a two component fit representing a rapid initial decay followed by a slower long term decay process similar to soil application of organic matter. Monitoring the decentralized MSWM practices in the city suggests that small scale composting and biomethanation is gaining acceptance and is the possible direction for OFMSW in growing cities.

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