Lau Kan Lung. / Thesis submitted in: November 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 286-312). / Abstracts in English and Chinese. / List of Symbols and Abbreviations --- p.I / List of Figures --- p.III / List of Tables --- p.XII / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Polycyclic aromatic hydrocarbons (PAHs) --- p.1 / Chapter 1.1.1 --- Physical and chemical properties of PAHs --- p.1 / Chapter 1.1.2 --- Formation of PAHs --- p.5 / Chapter 1.1.3 --- Sources of PAHs --- p.9 / Chapter 1.1.4 --- Regulations for contamination of PAHs --- p.13 / Chapter 1.1.5 --- Pollution of PAHs in environments of Hong Kong --- p.17 / Chapter 1.1.6 --- Toxicity of PAHs --- p.18 / Chapter 1.1.7 --- Fate of PAHs --- p.22 / Chapter 1.1.7.1 --- Sorption --- p.24 / Chapter 1.1.7.2 --- Volatilization --- p.25 / Chapter 1.1.7.3 --- Photooxidation --- p.25 / Chapter 1.1.7.4 --- Chemical oxidation --- p.27 / Chapter 1.1.7.5 --- Microbial degradation --- p.28 / Chapter 1.1.8 --- General principles of metabolism of PAHs --- p.30 / Chapter 1.2 --- Spent mushroom compost (SMC) --- p.35 / Chapter 1.2.1 --- Production of SMC --- p.35 / Chapter 1.2.2 --- Physical and chemical properties of SMC --- p.36 / Chapter 1.2.3 --- Availability of SMC --- p.40 / Chapter 1.2.4 --- Conventional applications of SMC --- p.43 / Chapter 1.2.5 --- Alternate use of SMC --- p.44 / Chapter 1.3 --- Objectives of the study --- p.48 / Chapter 1.4 --- Research strategy --- p.51 / Chapter 1.4.1 --- Effect of initial PAH concentration --- p.51 / Chapter 1.4.2 --- Effect of initial pH --- p.52 / Chapter 1.4.3 --- Effect of incubation time --- p.53 / Chapter 1.4.4 --- Effect of incubation temperature --- p.54 / Chapter 1.4.5 --- Putative identification of intermediates and/or breakdown products --- p.54 / Chapter 1.4.6 --- Isotherm plots and fitting into monolayer models --- p.55 / Chapter 1.4.6.1 --- Langmuir isotherm --- p.56 / Chapter 1.4.6.2 --- Freundlich isotherm --- p.58 / Chapter 1.4.7 --- Toxicological study by Microtox test --- p.59 / Chapter 1.4.8 --- Removal of PAH mixtures --- p.60 / Chapter 1.4.9 --- Specific goals of the study --- p.61 / Chapter 2 --- Materials and Methods --- p.62 / Chapter 2.1 --- Materials --- p.62 / Chapter 2.2 --- Physical and chemical analysis of SMC --- p.62 / Chapter 2.2.1 --- pH --- p.63 / Chapter 2.2.2 --- Electrical conductivity --- p.63 / Chapter 2.2.3 --- Salinity --- p.63 / Chapter 2.2.4 --- Ash content --- p.63 / Chapter 2.2.5 --- Metal contents --- p.64 / Chapter 2.2.6 --- Water-soluble anion contents --- p.65 / Chapter 2.2.7 --- "Carbon, hydrogen, nitrogen and sulfur contents" --- p.65 / Chapter 2.2.8 --- Infrared spectroscopic study --- p.66 / Chapter 2.2.9 --- Chitin content --- p.66 / Chapter 2.3 --- Soil collection and characterization --- p.67 / Chapter 2.4 --- Optimization for extraction --- p.67 / Chapter 2.5 --- Removal of PAHs --- p.68 / Chapter 2.5.1 --- Experimental design --- p.68 / Chapter 2.5.1.1 --- Pretreatment and incubation --- p.68 / Chapter 2.5.1.2 --- Extraction of sorbed PAHs in soil system or in SMC --- p.69 / Chapter 2.5.1.3 --- Extraction of PAHs in water system --- p.70 / Chapter 2.5.1.4 --- Putative identification and quantification of PAHs --- p.71 / Chapter 2.5.2 --- Assessment criteria --- p.72 / Chapter 2.5.3 --- Stability of PAHs --- p.77 / Chapter 2.5.4 --- Optimization for removal of PAHs --- p.78 / Chapter 2.5.4.1 --- Effects of initial PAH concentration and amount of SMC --- p.78 / Chapter 2.5.4.2 --- Effect of initial pH --- p.79 / Chapter 2.5.4.3 --- Effect of incubation time --- p.79 / Chapter 2.5.4.4 --- Effect of incubation temperature --- p.79 / Chapter 2.5.5 --- Putative identification of intermediates and/or breakdown products --- p.80 / Chapter 2.5.6 --- Isotherm plots and fitting into monolayer models --- p.80 / Chapter 2.5.6.1 --- Langmuir isotherm --- p.80 / Chapter 2.5.6.2 --- Freundlich isotherm --- p.81 / Chapter 2.5.7 --- Toxicological study of Microtox® test --- p.82 / Chapter 2.5.8 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.82 / Chapter 2.5.9 --- Removal abilities of different sorbents towards PAHs in water --- p.83 / Chapter 2.5.10 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.83 / Chapter 2.5.11 --- Statistical validation --- p.83 / Chapter 3 --- Results --- p.85 / Chapter 3.1 --- Characterization of soil --- p.85 / Chapter 3.1.1 --- Physical and chemical properties of soil --- p.85 / Chapter 3.1.2 --- GC-MS analysis of soil --- p.85 / Chapter 3.2 --- Calibration curves of PAHs --- p.85 / Chapter 3.3 --- Optimization for extraction --- p.91 / Chapter 3.4 --- Stability of PAHs --- p.101 / Chapter 3.4.1 --- Soil system --- p.101 / Chapter 3.4.1.1 --- Effect of incubation time --- p.101 / Chapter 3.4.1.2 --- Effect of incubation temperature --- p.101 / Chapter 3.4.2 --- Water system --- p.103 / Chapter 3.4.2.1 --- Effect of incubation time --- p.103 / Chapter 3.4.2.2 --- Effect of incubation temperature --- p.103 / Chapter 3.5 --- Characterization of SMC --- p.103 / Chapter 3.5.1 --- Physical and chemical properties of SMC --- p.103 / Chapter 3.5.2 --- GC-MS analysis of SMC --- p.106 / Chapter 3.5.3 --- Infrared spectroscopic study and chitin content --- p.106 / Chapter 3.5.4 --- Removal abilities of different sorbents towards PAHs in water --- p.121 / Chapter 3.5.5 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.121 / Chapter 3.6 --- Optimization for removal of PAHs --- p.124 / Chapter 3.6.1 --- Naphthalene --- p.124 / Chapter 3.6.1.1 --- Soil system --- p.124 / Chapter 3.6.1.1.1 --- Effects of initial naphthalene concentration and amount of straw SMC on removal efficiency --- p.124 / Chapter 3.6.1.1.2 --- Effects of initial naphthalene concentration and amount of straw SMC on removal capacity --- p.128 / Chapter 3.6.1.1.3 --- Effect of initial pH --- p.128 / Chapter 3.6.1.1.4 --- Effect of incubation time --- p.128 / Chapter 3.6.1.1.5 --- Effect of incubation temperature --- p.131 / Chapter 3.6.1.1.6 --- Putative identification of intermediates and/or breakdown products --- p.131 / Chapter 3.6.1.2 --- Water system --- p.134 / Chapter 3.6.1.2.1 --- Effects of initial naphthalene concentration and amount of straw SMC on removal efficiency --- p.134 / Chapter 3.6.1.2.2 --- Effects of initial naphthalene concentration and amount of straw SMC on removal capacity --- p.137 / Chapter 3.6.1.2.3 --- Effect of initial pH --- p.137 / Chapter 3.6.1.2.4 --- Effect of incubation time --- p.139 / Chapter 3.6.1.2.5 --- Effect of incubation temperature --- p.139 / Chapter 3.6.1.2.6 --- Putative identification of intermediates and/or breakdown products --- p.143 / Chapter 3.6.2 --- Phenanthrene --- p.145 / Chapter 3.6.2.1 --- Soil system --- p.145 / Chapter 3.6.2.1.1 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal efficiency --- p.145 / Chapter 3.6.2.1.2 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal capacity --- p.145 / Chapter 3.6.2.1.3 --- Effect of initial pH --- p.148 / Chapter 3.6.2.1.4 --- Effect of incubation time --- p.148 / Chapter 3.6.2.1.5 --- Effect of incubation temperature --- p.151 / Chapter 3.6.2.1.6 --- Putative identification of intermediates and/or breakdown products --- p.151 / Chapter 3.6.2.2 --- Water system --- p.155 / Chapter 3.6.2.2.1 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal efficiency --- p.155 / Chapter 3.6.2.2.2 --- Effects of initial phenanthrene concentration and amount of straw SMC on removal capacity --- p.155 / Chapter 3.6.2.2.3 --- Effect of initial pH --- p.157 / Chapter 3.6.2.2.4 --- Effect of incubation time --- p.157 / Chapter 3.6.2.2.5 --- Effect of incubation temperature --- p.161 / Chapter 3.6.2.2.6 --- Putative identification of intermediates and/or breakdown products --- p.163 / Chapter 3.6.3 --- Benzo[a]pyrene --- p.163 / Chapter 3.6.3.1 --- Soil system --- p.163 / Chapter 3.6.3.1.1 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal efficiency --- p.163 / Chapter 3.6.3.1.2 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal capacity --- p.167 / Chapter 3.6.3.1.3 --- Effect of initial pH --- p.167 / Chapter 3.6.3.1.4 --- Effect of incubation time --- p.168 / Chapter 3.6.3.1.5 --- Effect of incubation temperature --- p.168 / Chapter 3.6.3.1.6 --- Putative identification of intermediates and/or breakdown products --- p.172 / Chapter 3.6.3.2 --- Water system --- p.172 / Chapter 3.6.3.2.1 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal efficiency --- p.172 / Chapter 3.6.3.2.2 --- Effects of initial benzo[a]pyrene concentration and amount of straw SMC on removal capacity --- p.176 / Chapter 3.6.3.2.3 --- Effect of initial pH --- p.178 / Chapter 3.6.3.2.4 --- Effect of incubation time --- p.178 / Chapter 3.6.3.2.5 --- Effect of incubation temperature --- p.181 / Chapter 3.6.3.2.6 --- Putative identification of intermediates and/or breakdown products --- p.183 / Chapter 3.6.4 --- "Benzo[g,h,i]perylene" --- p.183 / Chapter 3.6.4.1 --- Soil system --- p.183 / Chapter 3.6.4.1.1 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal efficiency" --- p.183 / Chapter 3.6.4.1.2 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal capacity" --- p.187 / Chapter 3.6.4.1.3 --- Effect of initial pH --- p.187 / Chapter 3.6.4.1.4 --- Effect of incubation time --- p.187 / Chapter 3.6.4.1.5 --- Effect of incubation temperature --- p.189 / Chapter 3.6.4.1.6 --- Putative identification of intermediates and/or breakdown products --- p.189 / Chapter 3.6.4.2 --- Water system --- p.192 / Chapter 3.6.4.2.1 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal efficiency" --- p.192 / Chapter 3.6.4.2.2 --- "Effects of initial benzo[g,h,i]perylene concentration and amount of straw SMC on removal capacity" --- p.196 / Chapter 3.6.4.2.3 --- Effect of initial pH --- p.198 / Chapter 3.6.4.2.4 --- Effect of incubation time --- p.198 / Chapter 3.6.4.2.5 --- Effect of incubation temperature --- p.198 / Chapter 3.6.4.2.6 --- Putative identification of intermediates and/or breakdown products --- p.201 / Chapter 3.7 --- Isotherm plots and fitting into monolayer models --- p.205 / Chapter 3.7.1 --- Sorption of naphthalene --- p.205 / Chapter 3.7.2 --- Sorption of phenanthrene --- p.205 / Chapter 3.7.3 --- Sorption of benzo[a]pyrene --- p.208 / Chapter 3.7.4 --- "Sorption of benzo[g,h,i]perylene" --- p.208 / Chapter 3.8 --- Toxicological study of Microtox test --- p.208 / Chapter 3.8.1 --- Soil system --- p.214 / Chapter 3.8.2 --- Water system --- p.214 / Chapter 3.9 --- Operable conditions of SMC for removal of PAHs --- p.214 / Chapter 3.10 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.214 / Chapter 3.10.1 --- Soil system --- p.216 / Chapter 3.10.2 --- Water system --- p.216 / Chapter 4 --- Discussion --- p.221 / Chapter 4.1 --- Characterization of SMC --- p.221 / Chapter 4.2 --- Removal abilities of different sorbents towards PAHs in water --- p.223 / Chapter 4.3 --- Removal abilities of raw and autoclaved SMC towards PAHs in water --- p.226 / Chapter 4.4 --- Extraction efficiencies of PAHs --- p.227 / Chapter 4.5 --- Factors affecting removal of PAHs by SMC --- p.229 / Chapter 4.5.1 --- Initial PAH concentration and amount of straw SMC --- p.229 / Chapter 4.5.2 --- Initial pH --- p.237 / Chapter 4.5.3 --- Incubation time --- p.237 / Chapter 4.5.4 --- Incubation temperature --- p.242 / Chapter 4.6 --- Putative identification of intermediates and/or breakdown products --- p.247 / Chapter 4.7 --- Isotherm plots and fitting into monolayer models --- p.257 / Chapter 4.8 --- Toxicological study of Microtox® test --- p.258 / Chapter 4.9 --- Removal ability of SMC towards PAHs in single and in a mixture --- p.261 / Chapter 4.10 --- Comparison of removal efficiencies of benzo[a]pyrene by layering and mixing of straw SMC with soil --- p.265 / Chapter 4.11 --- Comparison of removal efficiencies of benzo[a]pyrene in different scales of experiment setup --- p.267 / Chapter 4.12 --- Effect of age of straw SMC on removal of PAHs --- p.270 / Chapter 4.13 --- Removal of benzo[a]pyrene by an aqueous extract of SMC --- p.270 / Chapter 4.14 --- Advantages of using SMC in removal of PAHs --- p.273 / Chapter 4.15 --- Limitations of the study --- p.278 / Chapter 4.16 --- Further investigation --- p.280 / Chapter 5 --- Summary --- p.282 / Chapter 6 --- Conclusion --- p.285 / Chapter 7 --- References --- p.286

O comportamento dos herbicidas no ambiente depende de sua composição química, do modo de aplicação e de fatores edafoclimáticos. Este estudo teve como objetivos avaliar em campo: i) a interferência dos resíduos florestais no controle das plantas daninhas e na eficácia de diferentes herbicidas aplicados na pré-emergência das plantas daninhas; ii) a seletividade dos diferentes herbicidas para as plantas de eucalipto e na atividade microbiológica do solo e iii) o efeito residual dos herbicidas. O experimento foi instalado em solo de textura argilosa na região de Capão Bonito, SP e cada parcela útil foi composta por três linhas com 8 m de comprimento. Foram usados quatro herbicidas aplicados na pré-emergência das plantas daninhas aplicados em área total e antes do plantio do híbrido Eucalyptus urophylla x grandis. A pesquisa foi instalada no delineamento blocos casualizados com cinco repetições, e sete tratamentos: 1) testemunha sem resíduo (linha de plantio com solo exposto após preparo de solo e retirada manual dos resíduos florestais da entrelinha de plantio); 2) testemunha com resíduo (linha de plantio com solo exposto após preparo de solo e manutenção dos resíduos florestais na entrelinha de plantio); 3) testemunha com controle (semelhante à testemunha com resíduo, mas com capina química das plantas daninhas durante o período de avaliação); 4) aplicação de isoxaflutole; 5) aplicação de sulfentrazone; 6) aplicação de flumioxazin; 7) aplicação de oxyfluorfen. Nos tratamentos de 4 a 7, os herbicidas foram aplicados na área total da parcela com costal pressurizada e mesmo volume de calda. Os efeitos dos tratamentos foram avaliados por meio da: i) avaliação visual de controle das plantas daninhas na linha e na entrelinha de plantio; ii) contagem e identificação das plantas daninhas emergidas após aplicação; iii) levantamento de sintomas de fitotoxidez e mensuração da altura da planta e do diâmetro do colo; iv) quantificação da atividade microbiológica no solo. A altura das plantas na área tratada com isoxaflutole foi 6,4 % superior comparativamente ao tratamento capinado. O flumioxazin controlou 85 % das plantas daninhas na linha de plantio aos 90 dias após aplicação (DAA), mas foi fitotóxica para algumas plantas, diminuindo a altura média. As precipitações pluviais e a temperatura atmosférica possivelmente influenciaram a eficácia do controle das plantas daninhas e a atividade dos microrganismos no solo. O preparo de solo na linha de plantio reduziu a germinação de plantas daninhas e aumentou a eficácia de controle das plantas daninhas, principalmente, nos tratamentos com flumixazin e oxyfluorfen. Em todos os tratamentos, as plantas de eucalipto recuperaram dos efeitos fitotóxicos ao longo de 150 DAA dos herbicidas. A atividade microbiana foi muito sensível às intervenções realizadas na área experimental. / The behavior of herbicides in the environment depends on its chemical composition, application and edaphoclimatic factors. This study aimed to evaluate the field: i) the interference of forest residues on weed control and effectiveness of different herbicides applied in the pre-emergence of weeds; ii) the selectivity of different herbicides for eucalypt plants and microbiological activity of the soil; and iii) the residual effect of herbicides. The research was installed in a clay soil in the region of Capão Bonito, SP and each useful plot area consisted of three rows with 8 m long. Four herbicides applied in the pre-emergence of weeds were applied in total area before planting the hybrid Eucalyptus urophylla x grandis. The experiment was conducted in a randomized block design with five replications and seven treatments: 1) control without residue (planting row with bare soil after preparation and manual removal of forest residues of planting interrow); 2) control with residue (planting row with bare soil after soil preparation and maintenance of forest residues in the planting interrow); 3) control weed free (similar to control with residue, but with weed chemical control during the evaluation period); 4) isoxaflutole application; 5) sulfentrazone application; 6) flumioxazin application ; 7) oxyfluorfen application. In treatment 4 to 7, the herbicides were applied at the total plot area with pressurized costal and same spray volume. The effects of the treatments were assessed by: i) visual assessment of weed control in the planting row and interrow; ii) counting and identification of weeds emerged after application; iii) survey of symptoms of phytotoxicity and measurement of plant height and base diameter; iv) measurement of microbiological activity in the soil. The height of the plants in the area treated with isoxaflutole was 6.4 % higher compared to weed free treatment. The flumioxazin controlled 85 % of the weeds in the planting row at 90 DAA, but was phytotoxic to some plants, reducing the average height. The rainfall and atmospheric temperature possibly influenced the effectiveness of weed control and activity of soil microorganisms. Soil preparation in the planting row reduced weed germination and increased weed control effectiveness, mainly in the treatments with flumixazin and oxyfluorfen. In all treatments, eucalyptus plants recovered from the phytotoxic effects over 150 DAA herbicides. Microbial activity was very sensitive to interventions in the experimental area.

Os compostos fenólicos pertencem a um grupo tóxico de poluentes ambientais descartados do processo de muitas indústrias tais como refinarias de óleo e indústrias químicas. Embora o fenol possua ação bactericida, alguns micro-organismos adquiriram a habilidade de se adaptar e utilizar este composto como fonte de carbono e energia, através do controle coordenado de vias metabólicas (catabólicas). A expressão destas vias pode ser regulada por: mecanismos de controle globais ou por uma via específica de resposta controlada, porém estes mecanismos ainda não são bem compreendidos. O presente trabalho pretendeu isolar e identificar micro-organismos de um ambiente contaminado para tratamento biológico de efluentes fenólicos, bem como analisar o padrão de proteínas citosólicas expressas em função da exposição à duas diferentes fontes de carbono (glicose ou fenol). As linhagens isoladas de Cubatão-SP foram identificadas pela amplificação e sequenciamento do gene 16S DNAr, resultando em 100 % de similaridade com os gêneros Achromobacter e Pandoraea. Os ensaios de biodegradação em diferentes concentrações de fenol (200 a 600 mg.L-1) mostraram que as duas linhagens foram capazes de degradar 100 % do fenol. As proteínas expressas por Achromobacter sp. em resposta ao fenol foram submetidas a eletroforese 2D e os resultados sugerem que a biodegradação do fenol foi realizada através da meta clivagem do anel aromático, pois três enzimas desta via foram identificadas (proteína degradação do fenol via meta- clivagem, 2- hidroximucônico semialdeído desidrogenase 1 e 4-hidroxi-2-oxovalerate aldolase). Outras enzimas envolvidas no metabolismo celular também foram identificadas, reforçando a hipótese que o fenol altera todo o metabolismo celular, envolvendo as mais diferentes vias metabólicas para que a célula possa superar o estresse celular ocasionado por esta exposição. / Phenolic compounds belong to a group of toxic environmental pollutants discharged from the process in many industries such as oil refineries and chemical plants. Although phenol has bactericidal action, some microorganisms acquired the ability to adapt and use this compound as a source of carbon and energy, through the coordinated control of metabolic pathways (catabolic). The expression of these pathways may be regulated by: control mechanisms via a global or specific response, but these mechanisms are not well understood. This work aims to isolate and identify micro-organisms from a contaminated environment for biological treatment of phenolic wastewaters, as well as analyzing the pattern of cytosolic proteins expressed in terms of exposure to two different carbon sources (glucose or phenol). The strains isolated from Cubatao-SP were identified by amplification and sequencing of 16S rDNA, resulting in 100% similarity with the genera Achromobacter and Pandoraea. The biodegradation assays at different concentrations of phenol (200 to 600 mg.L-1) showed that both strains were able of degrading 100% of the phenol. The proteins expressed by Achromobacter sp. in response to phenol were subjected to 2D electrophoresis and the results suggest that the biodegradation of phenol was performed using the meta cleavage of the aromatic ring, once three enzymes of this pathway have been identified (protein degradation meta-cleavage pathway phenol, 2-hydroxymuconic semialdehyde dehydrogenase 1 and 4-hydroxy-2-oxovalerate aldolase). Other enzymes involved in cellular metabolism were also identified; reinforcing the hypothesis that phenol modifies the entire cellular metabolism, involving very different metabolic pathways for the cell can overcome stress caused by this exposure.

O objetivo desse trabalho foi desenvolver e caracterizar blendas poliméricas dos copolímeros de poli(hidroxibutirato-co-hidroxivalerato) (PHBV) com poli(etileno-coacetato de vinila) (EVA) contendo altos teores de acetato de vinila (VA). Os teores de VA nos EVA utilizados foram de 65% (EVA65) e 90% (EVA90) em massa. Como as propriedades finais das blendas de PHBV, copolímero derivado de fonte renovável e biocompostável, com EVA, polímero de origem petroquímica e não biocompostável, são altamente dependentes do número de fases constituintes do sistema, esse trabalho investigou inicialmente a miscibilidade desses blendas. Assim, blendas contendo entre 10 e 90% (m/m) de EVA foram preparadas a partir do estado fundido em reômetro de torque e caracterizadas por calorimetria exploratória diferencial (DSC) e microscopia eletrônica de varredura (MEV). Os resultados da reometria de torque indicaram que o EVA65 sofreu degradação termomecânica (com ramificação e/ou reticulação das cadeias), enquanto que no PHBV predominou o processo de cisão. As blendas PHBV/EVA65 apresentaram duas transições vítreas e nítida separação de fases, em todas as composições, típicas de sistemas imiscíveis. Em contraste, o EVA90 não apresentou degradação nas condições de estudo. As curvas DSC das blendas PHBV/EVA90 apresentaram uma única temperatura de transição vítrea (Tg) cuja variação em função da fração em massa de cada componente foi prevista pela equação de Fox. As micrografias indicando a presença de uma única fase comprovam que as blendas PHBV/EVA90 são totalmente miscíveis em qualquer proporção. Após essa etapa, buscou-se avaliar a influência do teor de VA nas blendas PHBV/EVA. Para atingir esse objetivo, blendas contendo 5, 10, 20 e 30% (m/m) de EVA foram preparadas em extrusora dupla rosca co-rotacional interpenetrante e a influência do teor de VA na biodegradabilidade, morfologia e comportamento térmico e mecânico dessas blendas foi investigada por ensaio de biodegradação em solo, MEV, DSC, análise termo-dinâmico mecânica (DMA) e, ensaios mecânicos de tração e impacto. Além da influência sobre as transições térmicas dos polímeros mencionada anteriormente, os resultados de DSC mostraram que a temperatura de cristalização a frio (Tcc) e a entalpia de fusão (ΔHm) do PHBV aumentaram com o aumento do teor de EVA. Porém, o teor de VA e, consequentemente a miscibilidade das blendas, teve forte influência sobre a entalpia de cristalização a frio (ΔHcc) do PHBV. A presença do EVA65 reduziu significativamente os valores de ΔHcc, enquanto para as blendas preparadas com EVA90 esses valores foram superiores ao do polímero puro, sugerindo influência direta sobre a cinética de cristalização do PHBV. De uma maneira geral, as propriedades mecânicas em tração, tais como, resistência à tração e módulo elástico diminuíram com o aumento do teor de EVA, independentemente do teor de VA nas blendas. Entretanto, a deformação na ruptura foi altamente influenciada pelo teor de VA. Blendas PHBV/EVA65 apresentaram pequeno aumento na deformação na ruptura com o aumento do teor de EVA, provavelmente devido à fraca adesão interfacial entre seus os componentes. Já a deformação na ruptura de blendas PHBV/EVA90 contendo 30% (m/m) de EVA foi de 280%, muito superior à deformação na ruptura de 1,7% do PHBV. A taxa de biodegradação das blendas PHBV/EVA foi menor que a determinada para o PHBV. Apesar da baixa perda de massa determinada no PHBV e nas blendas PHBV/EVA após 180 dias de ensaio de biodegradação, foi possível observar que blendas PHBV/EVA65 apresentaram taxas de biodegradação superiores as apresentadas pelas blendas PHBV/EVA90. Além disso, blendas PHBV/EVA65 contendo altos teores de EVA apresentaram maiores taxas de biodegradação. Nas blendas PHBV/EVA90 as maiores taxas de biodegradação foram obtidas em composições contendo baixos teores de EVA. Esses resultados demonstraram que a miscibilidade afetou a biodegradabilidade das blendas PHBV/EVA de maneira negativa. / The aim of this work was to develop and characterize blends of poly (hydroxybutyrateco-hydroxyvalerate) (PHBV) and poly (ethylene-co-vinyl acetate) (EVA) containing high amount of vinyl acetate (VA). The VA amount in the EVA used here were 65% (EVA65) and 90% (EVA90) in mass. As the final properties of PHBV blends, a polymer derived from a renewable and biocompostable source with EVA, a polymer of petrochemical and non-biocompostable origin, are highly dependent on the number of constituent phases of the system. Therefore this work initially investigated the miscibility of these blends. PHBV/EVA blends containing 10 to 90% (m/m) of EVA were prepared from the molten state in a torque rheometer and characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results of the torque rheometry indicated that EVA65 chains underwent thermomechanical degradation with branching and / or crosslinking, while in PHBV the scission process predominated. The PHBV/EVA65 blends presented two vitreous transitions and distinct phase separation, typical of immiscible systems. In contrast, EVA90 showed no degradation in the study conditions. The DSC curves of the PHBV/EVA90 blends presented a single glass transition temperature (Tg) whose variation as a function of the mass fraction of each component was predicted by the Fox equation. The micrographs indicating the presence of a single phase prove that PHBV blends/EVA90 are totally miscible in any proportion. After this step, the influence of VA amount on the PHBV/EVA blends was studied. PHBV/EVA blends containing 5, 10, 20 and 30% (m/m) EVA were prepared in an interpenetrating co-rotational double screw extruder and the influence of VA content on the biodegradability, morphology and thermal and mechanical behavior of these blends was investigated by soil biodegradation test, SEM, DSC, dynamic mechanical analysis (DMA) and mechanical tensile and impact tests. In addition to the influence on the thermal transitions aforementioned, the DSC results showed that the cold crystallization temperature (Tcc) and the melting enthalpy (ΔHm) of PHBV increased with increasing EVA amount. However, the VA content and hence the miscibility of the blends, had a remarkable influence on the cold crystallization enthalpy (ΔHcc) of PHBV. The presence of EVA65 significantly reduced ΔHcc values, while for blends prepared with EVA90 these values were higher than that of pure polymer, suggesting a direct influence on PHBV crystallization kinetics. In general, mechanical tensile properties, such as tensile strength and elastic modulus decreased with increasing EVA content, regardless of the VA content in the blends. However, the deformation at rupture was highly influenced by the VA amount. PHBV/EVA65 blends exhibited small increase in the elongation at break with increasing EVA amount, probably due to the poor interfacial adhesion between their components. The elongation at break of PHBV/EVA90 blends containing 30% (m/m) of EVA was 280%, much higher than the elongation at break of 1.7% of neat PHBV. The biodegradation rate of PHBV/EVA blends was lower than that determined for PHBV. Despite the low loss of mass determined in PHBV and PHBV/EVA blends after 180 days of biodegradation test, it was possible to observe that PHBV/EVA65 blends had higher biodegradation rates than PHBV/EVA blends90. In addition, PHBV/EVA65 blends containing high EVA amount showed higher rates of biodegradation. In the PHBV/EVA90 blends the highest rates of biodegradation were obtained in compositions containing low EVA contents. These results demonstrated that the miscibility affected the biodegradability of PHBV/EVA blends negatively.

The nuclear waste inventory of the UK comprises large quantities of intermediate level wastes (ILW), which will be immobilised by encapsulation within a cementitious grout in stainless steel containers, followed by disposal in a deep engineered geological disposal facility (GDF) within a suitable geological formation. These wastes contain, in addition to radioactive elements, a heterogeneous mix of organic materials, including plastics, cellulose and rubber. Cellulosic items, such as cloth, tissue, filters, paper and wood, are considered particularly problematic, because they are known to be susceptible to degradation under alkaline conditions, forming small chain organic acids with the ability to complex metals and radionuclides. It is predicted that under alkaline conditions isosaccharinic acid (ISA) will form particularly strong complexes with Ni(II), Am(III), Eu(III), Np(IV), Th(IV), and U(IV). As a result, the presence of ISA could affect the migration behaviour of these elements, by increasing their solubility and reducing sorption, thus enhancing their mobility into the near and far field surrounding a GDF. During site operation and then after closure of a GDF, microbial communities have the potential to colonise the steep biogeochemical gradients, running from highly alkaline in the GDF “near field” to circumneutral pH conditions in the surrounding geosphere. Within these steep pH gradients microbial processes can control the fate of organic compounds, such as ISA, and have therefore been considered as an effective self-attenuating mechanism to remove ISA from the groundwater. This thesis aims to deliver a greater understanding of the microbial processes that can potentially use ISA as a carbon source and electron donor, removing it from solution, and thus having a positive impact on radionuclide mobility under GDF-relevant conditions. A microbial enrichment approach was chosen that approaches GDF-relevant conditions to explore the biodegradation of ISA. Cross-disciplinary analyses of water chemistry (pH, Eh, photospectroscopy, IC, ICP), mineralogy (ESEM, XRD, TEM, XAS) and microbiology (light microscopy, next generation sequencing) have demonstrated the ability of bacteria to degrade ISA over a wide range of biogeochemical conditions. Furthermore, key radionuclides (and their non-active analogues), including Ni(II) and U(VI), were precipitated from the groundwater system during ISA biodegradation. Moreover, in the case of uranium, microbial metabolism led to the reduction of U(VI) to U(IV), which is also less soluble. This study highlights the potential for microbial activity to help remove chelating agents from groundwaters surrounding an ILW GDF, and suggests that safety cases that do not include microbial processes may be overly conservative, over-estimating the impact of ISA on radionuclide transport.

La pollution des écosystèmes marins côtiers par les hydrocarbures, en particulier les HAPs, est un problème environnemental majeur. Le même constat est fait pour le littoral Sud de Sfax (Tunisie) dont la pollution presque généralisée menace sérieusement les ressources naturelles existantes dans la région. La caractérisation physico-chimique des échantillons marins prélevés à partir des trois ports (plaisance, commerce et pêche) de la ville de Sfax, prouve une contamination par des micropolluants organiques (hydrocarbures) et inorganiques (métaux) qui sont considérés comme des excellents traceurs de la pollution urbaine et industrielle et ils font partie des composés les plus toxiques étant donné leur faible biodégradation. La méthode d’empreinte moléculaire (PCR-SSCP) montre une dominance du domaine Bacteria suivie des Eucarya et des Archaea au sein des échantillons marins étudiés. Les analyses statistiques par le logiciel R ont montré l’absence de corrélation entre la communauté bactérienne identifiée par PCR-SSCP et les paramètres physico-chimiques étudiés.Dans une autre partie de travail, quatre souches bactériennes marines hydrocarbonoclastes ont été isolées et caractérisées sur les plans phénotypique et phylogénétique, après des enrichissements sur des HAPs et sur le pétrole brut: FLU5 de Bacillus stratosphericus, NAPH6 de Pseudomonas aeruginosa, PYR2 de Bacillus licheniformis isolées sur le fluoranthène, le naphtalène et le pyrène, respectivement, en présence de 30 g/l NaCl; et CO100 de Staphylococcus sp., isolée sur le pétrole brut, en présence de 100 g/l NaCl. Les analyses chromatographiques, GC-MS ou GC-FID, montrent les capacités biodégradatives intéressantes de ces composés récalcitrants par les bactéries isolées. En outre, ces quatre souches bactériennes, sont capables de produire des biosurfactants nommés BS-FLU5, BS-NAPH6, BS-PYR2 et BS-CO100, sur plusieurs sources de carbones, y compris l’huile de friture résiduelle, un substrat bon marché, minimisant ainsi le coût élevé de production de ces tensioactifs. Les analyses MALDI-TOF/MS, des biosurfactants BS-FLU5, BS-PYR2 et BS-CO100 purifiés, montrent qu’il s’agit des lipopeptides, les biosurfactants BS-NAPH6 sont de nature rhamnolipidique, sur la base des analyses FTIR. Ces quatre biosurfactants sont caractérisés par des propriétés tensiactives intéressantes : une faible CMC, une importante réduction de la tension de surface... Ils sont stables vis-à-vis d’une large gamme de pH, de température et de salinité. De plus, ces agents tensioactifs sont doués d’activité de remobilisation des hydrocarbures contenus dans des sols pollués par. Les biosurfactants BS-FLU5, BS-PYR2 et BS-CO100, présentent des activités anti-adhésives et anti-biofilms intéressantes contre des biofilms de certains microorganismes pathogènes. Par ailleurs, une propriété cicatrisante remarquable sur des plaies d’excision chez un modèle expérimental de rats de race Wistar, a été montrée par les quatre biosurfactants pour des concentrations de l’ordre de 5 et 10 mg/ml, en comparaison avec un cicatrisant de référence (CICAFLORA®). A noter que, l’évaluation de la cytotoxicité des biosurfactants étudiés, a montré qu’ils n’ont pas des effets toxiques sur des cellules rénales humaines HEK-239 à des concentrations jusqu’à 1000 µg/ml pour BS-FLU5 et BS-CO100 et jusqu’à 200 µg/ml pour BS-NAPH6 et BS-PYR2. La production des biosurfactants de la souche FLU5 à l’échelle pilote (deux fermenteurs de 20 et 100 litres, volume total), en présence d’un milieu économique, montre une augmentation des quantités des biosurfactants produits par rapport à l’échelle laboratoire (erlenmeyer, 1 litre). L’ensemble de ces résultats prometteurs, montrent que les souches marines isolées FLU5, NAPH6, PYR2 et CO100, ainsi que leurs biosurfactants demeurent d’intérêts biotechnologiques pour divers types d’applications, tels que la bioremédiation, l’agroalimentaire, la cosmétique... / Pollution of coastal marine ecosystems by hydrocarbons, in particular polycyclic aromatic hydrocarbons (PAHs), is a major environmental problem. The South coast of Sfax (Tunisia) is an example of a polluted ecosystem subject to both urbanization and industrialization including the outfall of untreated domestic sewage and wastewaters, fishery activities, as well as ship traffic and boat pollution. The physico-chemical characterization of the seawater taken from three harbours (pleasure, commercial and fishing) of the city of Sfax, showed a heavy contamination by organic and inorganic micropollutants. These are excellent tracers of urban and industrial pollution, and they are among the most toxic compounds due to their low biodegradation.The molecular fingerprinting technique (PCR-SSCP) showed the dominance of the Bacteria domain followed by Eucarya and Archaea within the studied marine samples. Statistical analysis using the R software, showed that no correlation was identified between the bacterial community identified by PCR-SSCP and the studied physico-chemical parameters.In another part, four marine, aerobic and hydrocarbonoclastic strains: Bacillus stratosphericus FLU5, Pseudomonas aeruginosa NAPH6, Bacillus licheniformis PYR2, isolated after enrichments on fluoranthene, naphthalene and pyrene, respectively, and in the presence of 30 g/l NaCl. Strain Staphylococcus sp. CO100 was isolated after enrichment on crude oil, in the presence of 100 g/l. Chromatographic analysis (GC-MS or GC-FID), showed the interesting biodegradative capacities of these recalcitrant compounds by the isolated bacteria.Besides, these strains showed their capacity to produce efficient surface active agents BS-FLU5, BS-NAPH6, BS-PYR2 and BS-CO100, on several substrates and in particular the residual frying oil, which is a cheap and renewable carbon source alternative, thus minimizing the high cost of producing surfactants. The MALDI-TOF/MS analysis of the purified BS-FLU5, BS-PYR2 and BS-CO100 biosurfactants revealed that they are belonging to lipopeptide family. FTIR analysis showed the glycolipid nature, more precisely the rhamnolipid type, of biosurfactant BS-NAPH6.These four biosurfactants are characterized by interesting tensioactive properties (low CMC, important surface tension reduction...). Furthermore, these surface active agents showed interest stability against a broad range of pH, temperature and salinity. The application of these biosurfactants, in oil recovery, from hydrocarbons-contaminated soil, showed that they were more effective on the hydrocarbon-remobilization than some tested synthetic surfactants. The biosurfactants BS-FLU5, BS-PYR2 and BS-CO100, were found to have notable anti-adhesif and anti-biofilm activities, being able to prevent and eliminate the biofilm formation by pathogenic microorganisms. Moreover, the four tested biosurfactants showed an interesting healing activity, on the wound site in a rat model. They increased significantly the percentage of wound closure when compared to the untreated and CICAFLORA® (a reference pharmaceutical product) treated groups, using two different concentrations (5 and 10 mg/l). Interestingly, the evaluation of the cytotoxicity of the studied biosurfactants, showed that they have no toxic effects on human HEK-239 cells at concentrations up to 1000 μg/ml for BS-FLU5 and BS-CO100 and up to 200 μg/ml for BS-NAPH6 and BS-PYR2. An attempt to produce biosurfactant produce by strain FLU5 on a pilot-scale (fermentors of 20 and 100 liter, as total volume), using a cost-effective medium, was also performed. Preliminary results showed an increase in the quantities of biosurfactantsBS-FLU5 produced on a pilot-scale compared to the lab-scale (Erlenmeyer of 1 liter).These results highlight the interest for potential use of strains FLU5, NAPH6, PYR2 and CO100, as well as their biosurfactants, in a wide variety of industrial, environmental and biotechnological applications.

Photolysis utilises short wavelength ultraviolet radiation to excite and cleave the carbon-chlorine bond of PCBs, yielding less chlorinated PCBs and ultimately biphenyl which can serve as energy and carbon source of various bacteria. Thus integration of photolysis and biodegradation can be a feasible remediation for PCB contamination. / Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants once used as industrial fluids (in hydraulic systems, gas turbines), dielectric fluids (capacitors, transformers), plasticizer (adhesives, textiles, sealants, copy paper), and heat exchangers due to their inertness as well as thermal and electrical insularity. However, they are found to be neurotoxic, immunosuppressive, hepatotoxic, and the USEPA classified PCBs as probable human carcinogens. Although the production of PCBs was banned by the US Congress in 1976, they persist in the environment because of their resistance. Upon entering the marine environment, PCBs will associate with particulates and ultimately with sediment due to their hydrophobic nature and thus sediment become a sink for PCBs. This exerts a threat to marine organisms and human who consume seafood. / The major sink of PCBs in the environment is marine sediment, and the presence of sediment particles as well as other sorbed chemicals may inhibit both photolysis and biodegradation. This study extracts PCBs from sediment and further purify them by various cleanups to prevent the effect of these materials on the efficiency of treatment. / Using 2,4,4'-trichlorobiphenyl (PCB 28), 2,2',5,5'-tetrachlorobiphenyl (PCB 52), 2,2',4,5,5'-pentachlorobiphenyl (PCB 101), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) and 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB 180) as model compounds, optimal UV intensity, reaction time, as well as reaction solvent were found to be dependent on the congeners used. While PCB 28 was highly reactive and PCB 101, PCB 153 and PCB 180 were comparatively easy to remove, PCB 52 showed high resistance towards photolysis. The photolysis of PCB mixture containing these five congeners with each of them in 1 mg/L was also being optimised. After optimisation, the reaction intermediates and products were identified by gas chromatography coupling mass spectrometry (GC-MS). Less chlorinated congeners and biphenyl were found, indicating stepwise dechlorination of PCB is the major pathway. (Abstract shortened by UMI.) / by Wong Kin Hang. / "August 2005." / Adviser: P. K. Wong. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0159. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 111-140). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Adequate wastewater management is a crucial element to achieve water sustainability in the petroleum refining sector, as their operations produce vast quantities of wastewater with potentially harmful contaminants. Treatment technologies are therefore pivotal for stopping these chemicals from entering the environment and protecting receiving environments. However, refining effluents are still linked to serious pollution problems, partly because little progress has been made in determining the causative agents of the observed biological effects, resulting in non-targeted treatment. Here it is shown that naphthenic acids, which have been reported as toxic and recalcitrant, are important components of refining wastewater resulting from the processing of heavy crude oil and that they have a significant contribution to the toxic effects exerted by these effluents. Furthermore, it was found that their chemical stability makes them highly resistant to remediation using Pseudomonas putida and H2O2/Fe-TAML (TetraAmido Macrocyclic Ligands) systems under laboratory conditions, and only sequential aliquots of Fe-TAML catalysts and H2O2 showed to partially degrade naphthenic acids (50 mg/L) within 72 hours. Results suggest that a combinatorial approach of Fe-TAML/H2O2 followed by biodegradation might improve current treatment options, but further optimisation is required for the biological treatment. These results can serve as a starting point for better environmental regulations relevant to oil refining wastewater resulting from heavy crude oil, as naphthenic acids are not currently considered in the effluent guidelines for the refining sector. Furthermore, the degradation of naphthenic acids under mild conditions using Fe-TAML/H2O2 systems indicates that these catalysts hold promise for the remediation of refining wastewater in real-life scenarios.

Les silicones acrylates photoréticulés sont largement utilisés dans les revêtements de divers matériaux. Leur production nécessite l’utilisation d’un photoamorceur considéré comme potentiellement reprotoxique, ce qui impose aux producteurs de revêtements silicones d’imaginer des formulations alternatives. L’augmentation de la consommation de ce type de revêtements amène à s’interroger sur leur devenir au cours et en fin de vie dans les filières de traitement des déchets et sur l’influence du changement de photoamorceur sur le comportement environnemental des revêtements. Ce domaine de recherche demande la mise en place d’une méthodologie spécifique, alliant des expériences de dégradation physico-chimiques et biologiques. Deux types de revêtements photoréticulés par deux photoamorceurs différents : le Darocur 1173 et Darocur 1173 modifié (nouveau photoamorceur) font l’objet de cette étude. L’exposition des revêtements silicones aux UV a montré que ces composés sont facilement dégradables et sensibles au photovieillissement. L’enduction silicone augmente, elle, la photosensibilité des films revêtus. Dans un contexte de fin de vie, les essais réalisés sur la matrice silicone ont permis de mettre en évidence une légère hydrolyse chimique des chaines siloxanes, non biodégradables aussi bien en aérobiose qu’en anaérobiose mais dont la présence n’inhibe pas l’activité microbienne. Les photoamorceurs testés présentent des comportements totalement différents face à la lixiviation et à la dégradation biologique: ainsi, le Darocur 1173 est très mobile en phase aqueuse, facilement assimilable par les microorganismes comme source primaire de carbone en conditions aérobies contrairement au Darocur 1173 modifié. Qu’il y ait eu biodégradation ou non, la structure de la communauté microbienne est influencée différemment suivant le photoamorceur utilisé. L’utilisation du Darocur 1173 modifié permet de diminuer le risque de migration et sa toxicité potentielle dans les revêtements silicones. La démarche mise en œuvre apporte de nombreuses informations quant aux impacts environnementaux et pourra servir d’exemple pour l’étude d’autres déchets silicones. / Photocrosslinked silicones acrylates are widely used in coatings of various materials. Their production requires the use of photoinitiator considered as potentially reprotoxic, which requires producers of silicone coatings to devise alternative formulations. Consumption increase of this type of coatings raises questions about their fate during and at their end-of-life in waste treatment channels and the influence of photoinitiator change on the environmental behavior of the coatings. This research area needs the use of a specific methodology, combining physico-chemical and biological degradation experiments. Two types of coatings photocrosslinked by two different photoinitiators: Darocur 1173 and modified Darocur 1173 (new photoinitiator) are the subject of this study. UV exposure of silicone coatings showed that these materials are easily degradable and sensitive to photoageing. The silicone coating increases the photosensitivity of coated films. At the end-of-life stage, performed experiments on silicone coatings revealed a slight chemical hydrolysis of the non-biodegradable siloxane chains, both under aerobic and anaerobic conditions. However, these materials does not inhibit the microbial activity. The tested photoinitiators have totally different behavior regarding the leaching and biological degradation: Darocur 1173 is very mobile in aqueous phase, easily assimilated by microorganisms as a primary sole of carbon under aerobic conditions in contrast to modified Darocur 1173. Whether there has been biodegradation or not, the structure of microbial communities is influenced differently depending on the used photoinitiator. Modified Darocur 1173 reduces the risk of migration and its potential toxicity in silicone coatings. The implemented approach brings a lot of information about the environmental impacts and can serve as an example for the study of other silicone waste.

Orientador: Sandra Mara Martins Franchetti / Banca: José Manoel Marconcini / Banca: Guilhermino José Macedo Fechine / Banca: José Carlos Marconato / Banca: Marcos Roberto Monteiro / Resumo: 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. / Abstract: 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. / Doutor