Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 115-119). Also available in electronic format on the Internet.

Thesis (Ph. D.)--Georgia State University, 2006. / Title from title screen. George E. Pierce,committee chair; Eric S. Gilbert, Sidney A. Crow, committee members. Electronic text (135 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Aug. 20, 2007. Includes bibliographical references (p. 120-124).

O herbicida ametrina é relativamente persistente no meio ambiente e está entre os cinco mais usados junto à cultura da cana-de-açúcar no Brasil. Técnicas radiométricas e moleculares foram utilizadas neste estudo para avaliar o potencial de sorção/dessorção e a biodegradação da ametrina, além do impacto do tempo de residência deste herbicida sobre a estrutura e a diversidade da comunidade microbiana, respectivamente. Os solos foram coletados em áreas florestais, sem histórico de aplicação de ametrina, sendo que um deles apresentou textura mais argilosa (NVef) e o outro mais arenosa (RQo). A ametrina apresentou baixo a moderado potencial de sorção (Kd = 2,2 e 9,9 L kg-1 nos solos RQo e NVef, respectivamente). Paralelamente, a taxa de biodegradação (t1/2 = 16 e 36 dias nos solos NVef e RQo, respectivamente) e a formação de resíduos ligados de 14C-ametrina ao solo (59 e 38 % da quantidade aplicada nos solos NVef e RQo, respectivamente) foram muito maiores no solo NVef, mostrando sua maior taxa de dissipação. Houve também a formação de um metabólito de importância ambiental, o qual correspondeu a 19 e 26 % da quantidade aplicada após 70 dias da aplicação nos solos RQo e NVef, respectivamente. O DNA total foi extraído dos solos, com posterior uso da técnica de Reação em Cadeia da Polimerase associada à Eletroforese em Gel com Gradiente Desnaturante (PCR-DGGE). A aplicação da ametrina alterou a estrutura da comunidade microbiana em ambos os solos, sendo essa alteração mais evidente no solo NVef, principalmente nos períodos inicias da incubação. Os dados de seqüenciamento evidenciaram o predomínio dos seguintes filos: Proteobacteria, Acidobacteria, Actinobacteria e Bacteroidetes. Houve seleção de alguns filos no solo NVef mesmo com apenas 7 dias de incubação da ametrina; entretanto, não houve redução no número de filos no solo RQo. Isto permitiu concluir que a diversidade da população microbiana pode variar com a aplicação do herbicida ametrina, mas isto dependerá principalmente do tipo de solo / The herbicide ametryne is relatively persistent in the environment and is among the five most used in the sugarcane crop in Brazil. Radiometric and molecular techniques were applied in this study to evaluate sorption/desorption and biodegradation of ametryne and the impact caused its residence time on the structure and diversity of the soil microbial community, respectively. The soils were collected from forested areas, with no history of ametryne application. One of them showed a clayey (NVef) and the other one a sandy (RQo) texture. Ametryne presented low to moderate sorption potential (Kd = 2.2 e 9.9 L kg-1 in the RQo and NVef soils, respectively). In parallel, the biodegradation rate (t1/2 = 16 and 36 days in the NVef and RQo, respectively) and the formation of soil bound residues of 14C-ametryne in soil (59 and 38 % of applied amount in the NVef and RQo, respectively) were much greater in NVef soil, showing its higher dissipation rate. There was also formation of a metabolite of environmental importance, which corresponded to 19 and 26 % of applied amount in the RQo and NVef soils, respectively. The genomic soil DNA was extracted with further application of the Polymerase Chain Reaction associated to the Denaturing Gradient Gel Electrophoresis (PCR-DGGE) technique. Ametryne application changed the structure of microbial community in both soils, but this change was more pronounced in the NVef soil, mainly in the initial periods of incubation. The sequencing data showed predominance of the following phyla: Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes. There was selection of certain phyla in the NVef, even only with 7 days of ametryne application; however, there was no reduction in the phyla number in the RQo. This led to the conclusion that microbial population diversity may vary with ametryne application, but it will depend on the soil type

Made available in DSpace on 2014-06-11T19:32:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-30Bitstream added on 2014-06-13T19:03:39Z : No. of bitstreams: 1 goncalves_spc_dr_rcla.pdf: 5626530 bytes, checksum: 213f4e6ddace53c7f1d5646655814102 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Neste trabalho, estudou-se a biodegradação dos filmes de PHB-V, PCL, PP e das blendas de PCL/PHB-V (4:1) e PP/PHB-V (4:1) em solo. Os filmes poliméricos foram preparados por compressão a quente e analisados através das análises de infravermelho com transformada de Fourier (FTIR), microscopia eletrônica de varredura (MEV), calorímetria exploratória diferencial (DSC), termogravimetria (TG) e difração de raio-X (DRX), para investigar os processos de biodegradação por um período de 120 dias. A atividade microbiana foi monitorada durante todo o período de experimento, bem como vários parâmetros: pH, temperatura, umidade, matéria orgânica, quantidade de CO2 e quantificação de microrganismos. Após os diferentes tempos do ensaio em solo, os filmes poliméricos apresentaram alterações quanto a sua estrutura molecular e morfologia em diferentes intensidades. Os processos de biodegradação observados nos diferentes filmes poliméricos, ocorreram via erosão superficial. O filme de PHB-V, foi o mais suscetível ao ataque microbiano, sendo completamente decomposto em 30 dias. O grau de cristalinidade de PHB-V permaneceu inalterado, pois a biodegradação ocorreu simultaneamente nas fases amorfa e cristalina. Para os filmes de PCL a biodegradação ocorreu tanto na fase amorfa como na interface do polímero. Os filmes de PP, após a biodegradação apresentaram uma ordenação na estrutura cristalina, denominada como “quemi-cristalização”. A biodegradação das blendas de PCL/PHB-V (4:1) e PP/PHB-V (4:1) ocorreu na interfase dos dois componentes da blenda, indicando que a imiscibilidade/morfologia são fatores que influenciam significativamente no processo de degradação. / In this works, we studied the biodegradation of the films of PHB-V, PCL, PP and the blends of PCL / PHB-V (4:1) and PP / PHB-V (4:1) in soil. The polymer films were prepared by melt-pressing and was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry (TGA) and X-ray diffraction (XRD), and investigated with respect to their microbial degradation in soil after 120 days. Microbial activity was monitored during the whole experiment, and various parameters: pH, temperature, moisture, organic matter, amount of CO2 and quantification of microorganisms. After different times of the test in soil, the polymer films showed changes in their molecular structure and morphology in different intensities. The processes of biodegradation observed in various polymer films, occurred via surface erosion. The film of PHB-V was the most susceptible to microbial attack and was completely decomposed in 30 days. The degree of crystallinity of PHB-V remained unchanged since the degradation occurred in both crystalline and amorphous phases. For films of PCL biodegradation occurred in both the amorphous phase as the interface of the polymer. The films of PP after biodegradation underwent an arrangement of the crystalline structure, known as chemi-crystallization. The biodegradation of the blends of PCL / PHB-V (4:1) and PP / PHB-V (4:1) occurred in the interphase of the two components of the blends, indicating that the immiscibility/morphology are factors that significantly influence the process of degradation.

Made available in DSpace on 2014-06-11T19:32:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-10-11Bitstream added on 2014-06-13T19:03:39Z : No. of bitstreams: 1 jesus_gj_dr_rcla.pdf: 4895578 bytes, checksum: 6970fd46e2b766b5810c294018cd18da (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho utilizou Neurospora crassa 74A em sua forma paramorfogênica, para avaliar o processo inicial da remoção da cor de efluentes aquáticos, que se desenvolveu em duas etapas; a biosorção e a biodegradação. Nos espectros de UV-Vis foi possível estabelecer o grau de remoção do corante por biosorção, seguido, após um tempo mais longo de contato, do início de processo biodegradativo; em que ficou caracterizado, principalmente, o aparecimento de bandas, indicando a presença de aminas primárias, após 120 horas de contato. Deste modo, pode-se deduzir que o fungo após esgotar sua fonte de carbono decorrente do inóculo, recorreu à fonte de carbono alternativo, vindo do substrato mais próximo, ou seja, das moléculas de corantes. No estudo da tolerância ficou evidenciado que todos os corantes estudados apresentaram fatores que provocaram uma diminuição da produção de biomassa, contudo, foi possível com a determinação da Concentração Efetiva (EC50), que caracteriza a inibição ou mortalidade de 50% dos organismos testados, para saber o grau de toxicidade destes corantes. Os mais tóxicos foram Procion Red MX-5B em pH 2,50; seguido do Acid Red 151 em pH 2,50. Menos tóxicos foram Direct Red 23 no pH 6,50 e Erythrosine B no pH 4,50. / In this research Neurospora crassa 74A in its paramorphogenic form was used to evaluate the initial process of the dye removal from water effluents, which was carried out in two steps; biosorption and biodegradation. It was possible to establish in the UV-Vis spectra a dye removal degree through biosorption, soon after a longer contact time between the microorganism and the dye, beginning the biodegradative process. In which it was mainly characterized the band appearance, pointing out the presence of primary amines after 120-hours contact. Thus, it can be deduced that the fungus after exhausting its carbon source due to the innoculum, it came after the alternative carbon source, coming from nearer substrate, that its, the dye molecules. The tolerance study showed that all dyes presented factors, which induced a decrease in the biomass production; however, it was possible to know the toxicity of the dyes because of the determination of the EC50. The most toxics were (Procion Red MX-5B at pH 2.50); followed by (Acid Red 151 at pH 2.50). The less toxics were (Direct Red 23 at pH 6.50) and (Erythrosine B at pH 4.50).

Made available in DSpace on 2014-10-09T12:28:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:45Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientador: José Carlos Marconato / Banca: Regina Teresa Rosim Monteiro / Banca: Adriana de Campos Pastre / Resumo: Recentemente o mundo começou a se preocupar com o consumo exacerbado de embalagens e a sua rápida descartabilidade. Por conseguinte, alternativas de amenização deste problema têm sido propostas tais como a utilização de plásticos biodegradáveis, o uso de blendas poliméricas e o emprego de aditivos que facilitem a biodegradação. Sendo assim, este trabalho teve por objetivo avaliar os diferentes tratamentos: foto, bio e foto/biotratamento, aplicados na degradação de filmes finos de PEBD, PHB e de suas blendas, empregando o fungo P. chrysosporium CCB 478 no processo biodegradativo. As blendas de PEBD/PHB foram preparadas nas composições de 90:10, 80:20 e 70:30 (m/m) juntamente com os filmes de homopolímeros pelo processo de prensagem sob aquecimento. As amostras foram submetidas à radiação UV e em seguida foram aplicados os testes de biodegradação em meio mineral líquido com o fungo P. chrysosporium CCB 478 pelo período de 120 dias. Análises de perda de massa, ângulo de contato, FTIR, análises visuais, microscopia óptica, MEV, foram técnicas utilizadas para avaliar a biodegradação. O fototratamento realizado com todas as amostras dos filmes foi relevante para o processo de adesão e colonização da superfície dos filmes. As blendas de composição 70/30 e 80/20 apresentaram alterações morfológicas e estruturais mais significativas, por MEV e FTIR, além de apresentaram melhores resultados de biodegradação, após a fotoirradiação. / Abstract: Recently the world began to worry about the high consumption and rapid disposability of packaging. Therefore, alternatives to improve this problem have been proposed such as use of biodegradable plastics, polymer blends and additivies which facilitates the biodegradation. Thus, this study aimed to evaluate the results of different treatments: biotreatment, phototreatment, and photo/biotreatment, applied on the degradation of thin films of LDPE, PHB and its blends, using as fungus Phanerochaete chrysosporium CCB 478 in biodegradation process. Blends of LDPE/PHB were prepared in the compositions of 90:10, 80:20 and 70:30 (m/m) along with homopolymers films by pressing process under heating. Samples were exposed to UV radiation and then were submitted to the biodegradation tests in liquid mineral medium with the P. chrysosporium CCB 478 fungus for 120 days. Analysis of weight loss, contact angle, FTIR, visual analysis, optical microscopy and SEM, were employed to estimate biodegradation. Phototreatment applied to all films was relevant to the adhesion process and colonization the surface films. The blends of composition 70/30 and 80/20 showed significant morphological and structural changes, verified by SEM and FTIR techniques, besides showed better results of biodegradation after photoirradiation. / Mestre

abstract: Intimate coupling of Ti2 photocatalysis and biodegradation (ICPB) offers potential for degrading biorecalcitrant and toxic organic compounds much better than possible with conventional wastewater treatments. This study reports on using a novel sponge-type, Ti2-coated biofilm carrier that shows significant adherence of Ti2 to its exterior and the ability to accumulate biomass in its interior (protected from UV light and free radicals). First, this carrier was tested for ICPB in a continuous-flow photocatalytic circulating-bed biofilm reactor (PCBBR) to mineralize biorecalcitrant organic: 2,4,5-trichlorophenol (TCP). Four mechanisms possibly acting of ICPB were tested separately: TCP adsorption, UV photolysis/photocatalysis, and biodegradation. The carrier exhibited strong TCP adsorption, while photolysis was negligible. Photocatalysis produced TCP-degradation products that could be mineralized and the strong adsorption of TCP to the carrier enhanced biodegradation by relieving toxicity. Validating the ICPB concept, biofilm was protected inside the carriers from UV light and free radicals. ICPB significantly lowered the diversity of the bacterial community, but five genera known to biodegrade chlorinated phenols were markedly enriched. Secondly, decolorization and mineralization of reactive dyes by ICPB were investigated on a refined Ti2-coated biofilm carrier in a PCBBR. Two typical reactive dyes: Reactive Black 5 (RB5) and Reactive Yellow 86 (RY86), showed similar first-order kinetics when being photocatalytically decolorized at low pH (~4-5), which was inhibited at neutral pH in the presence of phosphate or carbonate buffer, presumably due to electrostatic repulsion from negatively charged surface sites on Ti2, radical scavenging by phosphate or carbonate, or both. In the PCBBR, photocatalysis alone with Ti2-coated carriers could remove RB5 and COD by 97% and 47%, respectively. Addition of biofilm inside macroporous carriers maintained a similar RB5 removal efficiency, but COD removal increased to 65%, which is evidence of ICPB despite the low pH. A proposed ICPB pathway for RB5 suggests that a major intermediate, a naphthol derivative, was responsible for most of the residual COD. Finally, three low-temperature sintering methods, called O, D and DN, were compared based on photocatalytic efficiency and Ti2 adherence. The DN method had the best Ti2-coating properties and was a successful carrier for ICPB of RB5 in a PCBBR. / Dissertation/Thesis / M.S. Biological Design 2011

Orientador: Lara Durães Sette / Banca: Maria Aparecida Marin Morales / Banca: Carlos Renato Corso / Banca: Valeria Maia de Oliveira / Banca: Vera Maria Valle Vitali / Resumo: Considerando a importância dos processos de biorremediação, o presente trabalho teve como objetivo principal avaliar o potencial de consórcios microbianos, constituídos por quatro fungos filamentosos isolados de invertebrados marinhos e duas bactérias recuperadas de reservatório de petróleo, na destoxificação de poluentes ambientais, por meio da sobrevivência do microcrustáceo Artemia sp. e da luminescência da bactéria Vibrio fischeri. Após estudos de antagonismo entre os micro-organismos, foram estruturados oito consórcios microbianos, em diferentes combinações. Os consórcios foram usados, isoladamente, para avaliar a toxicidade dos poluentes ambientais corante têxtil RBBR (Remazol Brilliant Blue R), óleo diesel e hidrocarbonetos policíclicos aromáticos. Dentre os consórcios estudados, o consórcio 3, composto por dois fungos filamentosos e pelas duas bactérias, apresentou melhores resultados de destoxificação do corante RBBR e óleo diesel, após sete dias de cultivo a 28 oC e 140 rpm. As enzimas ligninolíticas apresentaram atividade baixa ou ausente no teste feito com o corante e com o óleo diesel. Para o benzo[a]pireno (BaP), apesar de ter havido uma produção mais expressiva de enzimas ligninolíticas, os resultados de destoxificação foram incoerentes, por não apresentar toxicidade mesmo em elevadas concentrações. Sendo assim, no presente estudo o consórcio 3 foi empregado na otimização da destoxificação e descoloração do corante RBBR. Os resultados de dois planejamentos do tipo Plackett-Burman (PB1 e PB2) e um DCCR (Delineamento Composto Central Rotacional) revelaram que as melhores condições de destoxificação/descoloração foram obtidas no ensaio 11 do PB1 e no ensaio 2 do PB2. As condições de cultivo desses dois ensaios foram submetidas a experimentos de validação, porém ... (Resumo completo, clicar acesso eletrônico) / Abstract: Taking into account the relevance of bioremediation processes, the present work aimed to evaluate the potential of microbial consortia composed by four filamentous fungi isolated from marine invertebrates and two bacteria recovered from oil reservoirs in the detoxification of environmental pollutants, through the survival of the microcrustacean Artemia sp. and the luminescence of the bacterium Vibrio fischeri. After studies of antagonism between the microorganisms, eight microbial consortia were structured in different combinations. The consortia were tested separately against the environmental pollutants RBBR (Remazol Brilliant Blue R) textile dye, diesel oil, and polycyclic aromatic hydrocarbons. Among the consortia studied, the consortium 3, composed of two filamentous fungi and two bacteria presented better results of RBBR dye and diesel detoxification after seven days at 28 oC and 140 rpm. Ligninolytic enzymes showed low or absent activity in the experiments containing RBBR and diesel. For benzo[a]pyrene (BaP), although there was a more expressive production of ligninolytic enzymes, the results of detoxification were incoherent, since no toxicity was showed even at high concentrations. Therefore, in the present study the consortium 3 was used to optimize detoxification and discoloration of RBBR dye. Results from two Plackett-Burman designs (PB1 and PB2) and one CCD (Central Composite Design) revealed that the best conditions for detoxification/ discoloration were obtained in the assay 11 from PB1 and assay 2 from PB2. The culture conditions of this two assays were submitted to validation experiments, however only assay 2 from PB2 (4 cylinders (0.5 cm) of each fungus, and 4 mL of each bacteria (OD 0.4), 1 g/50 mL wheat bran, 100 % artificial sea water, pH 8, and 500 ppm RBBR) presented ... (Complete abstract click electronic access below) / Doutor

abstract: In this work, the vapor transport and aerobic bio-attenuation of compounds from a multi-component petroleum vapor mixture were studied for six idealized lithologies in 1.8-m tall laboratory soil columns. Columns representing different geological settings were prepared using 20-40 mesh sand (medium-grained) and 16-minus mesh crushed granite (fine-grained). The contaminant vapor source was a liquid composed of twelve petroleum hydrocarbons common in weathered gasoline. It was placed in a chamber at the bottom of each column and the vapors diffused upward through the soil to the top where they were swept away with humidified gas. The experiment was conducted in three phases: i) nitrogen sweep gas; ii) air sweep gas; iii) vapor source concentrations decreased by ten times from the original concentrations and under air sweep gas. Oxygen, carbon dioxide and hydrocarbon concentrations were monitored over time. The data allowed determination of times to reach steady conditions, effluent mass emissions and concentration profiles. Times to reach near-steady conditions were consistent with theory and chemical-specific properties. First-order degradation rates were highest for straight-chain alkanes and aromatic hydrocarbons. Normalized effluent mass emissions were lower for lower source concentration and aerobic conditions. At the end of the study, soil core samples were taken every 6 in. Soil moisture content analyses showed that water had redistributed in the soil during the experiment. The soil at the bottom of the columns generally had higher moisture contents than initial values, and soil at the top had lower moisture contents. Profiles of the number of colony forming units of hydrocarbon-utilizing bacteria/g-soil indicated that the highest concentrations of degraders were located at the vertical intervals where maximum degradation activity was suggested by CO2 profiles. Finally, the near-steady conditions of each phase of the study were simulated using a three-dimensional transient numerical model. The model was fit to the Phase I data by adjusting soil properties, and then fit to Phase III data to obtain compound-specific first-order biodegradation rate constants ranging from 0.0 to 5.7x103 d-1. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2012