O desenvolvimento de metodologias eletroanalíticas altamente eficientes para a determinação de resíduos de pesticidas em amostras de alimentos usando a radiação de ultra-som (US) e o eletrodo de diamante dopado com boro (DDB) é reportado neste trabalho.Também são apresentadas tentativas para melhorar a degradação eletroquímica de pesticidas e de seus metabólitos no ambiente usando estas novas ferramentas (US e DDB) para minimizar o bloqueio da superfície eletródica que, usualmente, impede tais processos.A primeira parte do trabalho apresenta a determinação do metilparation (MP), do seu produto de degradação 4-nitrofenol (4-NF) e do carbaril em água pura e em amostras de alimentos, por voltametria de onda quadrada (SWV) na ausência e na presença do ultra-som usando o eletrodo de DDB. Os resultados obtidos em água pura foram comparados com os dados obtidos por cromatografia líquida de alta eficiência.As metodologias sonoeletroanalíticas para todos os analitos em água pura e nas matrizes de alimentos apresentaram maior sensibilidade e precisão e menores limites de detecção (LD) e de quantificação (LQ) em relação às medidas silenciosas. Para a redução do MP e do 4-NF e para a oxidação do carbaril em água pura, o LD diminuiu de 10,8 para 4,86 μg L-1, de 6,38 para 2,57 μg L-1 e de 2,96 para 2,08 μg L-1, respectivamente. Para a detecção do MP em extrato de batata e do 4-NF em suco de limão, o valor do LD diminuiu de 36,6 para 10,1 μg L-1 e de 13,8 para 8,32 μg L-1, respectivamente.Em todos os casos, foi observado que os valores de LD e LQ estão dentro da concentração máxima permitida para os compostos em amostras de alimentos (50 e 500 μg kg-1 para amostras de batata e de milho, respectivamente, de 1000 μg kg-1 para frutas cítricas e de 500 μg kg-1 para amostras de abacaxi). Satisfatórios valores de recuperação dos analitos nas amostras indicam a possibilidade da determinação direta do MP em extratos de batata e de milho (83 a 96 %) e do 4-NF em sucos de laranja e de limão (84 a 94 %) e também para a detecção do carbaril em suco de abacaxi após o procedimento de extração líquido-líquido (89 a 92 %). Inicialmente, não foram encontrados resíduos detectáveis dos compostos em todas essas amostras de alimentos.As vantagens observadas para os estudos na presença do ultra-som são devidas ao aumento do transporte de espécies até a superfície eletródica e também à limpeza da superfície, visto que a limpeza intermediária não é necessária, resultando em análises mais rápidas e reprodutíveis.Na segunda parte do trabalho, os efeitos benéficos do ultra-som, particularmente a limpeza da superfície eletródica, foram avaliados em associação às eletrólises potenciostáticas para a degradação do pentaclorofenol (PCF) a 0,9, 2,0 e 3,0 V vs. Ag/AgCl e do carbaril a 3,0 V vs. Ag/AgCl.Para o pentaclorofenol, as eletrólises a 0,9 V mostraram que o bloqueio da superfície eletródica foi mais rápido na sonoeletrólise em relação ao processo na ausência do ultra-som, devido à formação de um composto dimérico na superfície eletródica. Eletrólises a 2,0 V e a 3,0 V mostraram maiores níveis de decaimento das bandas do PCF para os estudos na presença do ultra-som em relação àqueles obtidos por medidas silenciosas, devido ao aumento do transporte de massa, minimização da inativação do eletrodo e geração simultânea de radicais hidroxila pelo ultra-som e pela superfície polarizada do DDB. Resultados similares àqueles obtidos para o pentaclorofenol no maior valor de potencial foram também observados para a degradação do carbaril a 3,0 V. / The development of highly efficient electroanalytical methodologies for the determination of pesticide residues in food samples using ultrasound radiation (US) and a boron-doped diamond (BDD) electrode is reported in this work.Also reported are attempts to improve the electrochemical degradation of pesticides and their metabolites in the environment by using those new tools (US and BDD) to minimize the blockage of the electrode surface that usually hinders such processes.The first part of the work presents the determination of methylparathion (MP), their degradation product 4-nitrophenol (4-NP) and carbaryl in pure water and food samples by square wave voltammetry (SWV) in the absence and presence of ultrasound using the BDD electrode. The results obtained in pure water were compared with the high performance liquid chromatography data.The sonoelectroanalytical methodologies for all analytes in pure water and food matrices showed greater sensitivity and precision and lower limits of detection (LOD) and quantification (LOQ) than the silent measurements. For the reduction of MP and 4-NP and oxidation of carbaryl in pure water, the LOD diminished from 10.8 to 4.86 μg L-1, from 6.38 to 2.57 μg L-1 and from 2.96 to 2.08 μg L-1, respectively. For the detection of MP in potato extract and of 4-NP in lemon juice, the LOD value diminished from 36.6 to 10.1 μg L-1 and from 13.8 to 8.32 μg L-1, respectively.In all cases, it was observed that the LOD and LOQ values are inside of the maximum allowed concentration for compounds in food samples (50 and 500 μg kg-1 for potato and corn samples, respectively, 1000 μg kg-1 for citrus fruit and 500 μg kg-1 for pineapple sample). Satisfactory recovery values for the analytes in the samples indicate the possibility of the direct determination of MP in potato and corn extracts (83 to 96 %) and 4-NP in orange and lemon juices (84 to 94 %) and also for the detection of carbaryl in a pineapple juice after a liquid-liquid extraction procedure (89 to 92 %). In all these food samples, no initial detectable residues of the compounds were found.The advantages observed for the insonated studies are due to the increase in the mass transport of species to the electrode surface and also to the cleaning of the surface, since the intermediary cleaning is not necessary thus resulting in a more rapid and reproducible analysis.In the second part of the work, the beneficial effects of the ultrasound, particularly the cleaning of electrode surface, were evaluated in association to potentiostatic electrolyses for the degradation of pentachlorophenol (PCP) at 0.9, 2.0 and 3.0 V vs. Ag/AgCl and for carbaryl at 3.0 V vs. Ag/AgCl.For pentachlorophenol the electrolyses at 0.9 V showed that the blockage of the electrode surface was faster in the sonoelectrolysis than in the absence of ultrasound due to the formation of a dimeric compound on the electrode surface. Electrolyses at 2.0 V and 3.0 V showed greater decay levels of the PCP bands for insonated studies than those obtained for the silent measurements, due the increase of mass transport, minimization of the electrode fouling and to the added generation of hydroxyl radicals by both ultrasound and the polarized BDD surface. Similar results to those for pentachlorophenol at the higher potential were also observed for the degradation of carbaril at 3.0 V.

O estudo de polímeros condutores desperta um enorme interesse científico e tecnológico devido às diversas aplicações possíveis para esses materiais, como o desenvolvimento de dispositivos eletro-eletrônicos e sensores. Através de processos de dopagem esses polímeros tornam-se eletroativos, possibilitando por meio de técnicas eletroquímicas a determinação de diversas substâncias. Na agropecuária, a utilização intensiva e crescente de produtos químicos como pesticidas e fertilizantes, tem provocado diversas contaminações e agressões, despertando interesse na utilização de sensores para o monitoramento dessas substâncias em tempo real. Os eletrodos modificados com polímeros condutores têm-se apresentado como uma alternativa devido a algumas peculiaridades como alta estabilidade física e química e excelentes possibilidades analíticas devido à versatilidade da polimerização eletroquímica. Este trabalho teve como objetivo o desenvolvimento de novos materiais de eletrodos modificados com polímeros condutores para a determinação eletroanalítica de pesticidas. Os pesticidas estudados foram os herbicidas 2,4-D, bentazon, glifosato, paraquat e o inseticida paration metílico. Foram realizadas medidas voltamétricas e de impedância com eletrodos de carbono vítreo, pasta de carbono e eletrodos modificados com polianilina e polipirrol, visando a obtenção de sensores para a detecção destes pesticidas. Estudos de interação dos pesticidas com os polímeros foram realizados utilizando-se a técnica de espectrofotometria de UV-visível para a determinação da concentração dos pesticidas em estudos cinéticos. Também utilizou-se a espectroscopia de impedância eletroquímica para auxiliar no entendimento das interações entre os pesticidas e os polímeros condutores. Adicionalmente foi aplicada uma metodologia de análise de fluxo descontínuo (BIA), utilizada com sucesso na determinação de metais, para a determinação de pesticidas. Os resultados mostraram uma seletividade nas interações entre os polímeros condutores e os pesticidas. Por meio da resposta voltamétrica dos polímeros condutores, os eletrodos de pasta modificados com polianilina e polipirrol mostraram-se hábeis na detecção dos pesticidas não eletroativos como o 2,4-D, o bentazon e o glifosato, bem como na determinação do paraquat. Estes resultados atribuem aos eletrodos modificados desenvolvidos neste trabalho a característica de sensores de diagnóstico da presença destes pesticidas em solução. A metodologia de BIA na determinação de pesticidas, apresentou inúmeras vantagens do ponto de vista analítico, como a não renovação da superfície de eletrodo, micro-volumes de injeção de amostra, dezenas de análise sem troca do eletrólito suporte, tempos de análise inferiores a um segundo bem como a possibilidade de utilização de dispositivo portátil para análises em campo. / Studies of conducting polymers have great technological and scientific interest due to many possibilities of applications like the development of electronic devices and sensors. By means of a doping process these polymers became electroactives, allowing the determination of substances that specifically interact with the polymers. In agriculture the intensive and constant use of chemical substances as pesticides and fertilizers are causing several environmental contamination and the development of sensors for real time analysis has been a research field of intense interest. Electrodes modified with conducting polymers have several interesting characteristics as their high physical and chemical stability and excellent analytical possibilities, due to the versatility of the electrochemical polymerization. The objective of the present work was the development of electrode materials modified with conducting polymers for the electroanalytical determination of pesticides. The pesticides studied were the herbicide 2,4-D, bentazon, gliphosate and paraquat and the insecticide methylparathion. Voltammetric measurements were performed on glassy carbon and carbon paste electrodes modified with polianiline and polipirrol to obtain a procedure for the pesticides measurement. Studies of interaction between the pesticides and the polymers were performed using UV-visible spectrophotometry for pesticide concentration determination kinetic sorption experiments and the electrochemical impedance technique was also used to evaluate such sorption processes. Batch Injection Analysis (BIA), a technique successfully used for the analysis of metals, was also tested for the determination of the herbicide paraquat. Results obtained from the kinetic studies and the voltammetric and impedance experiments showed some selectivity for the interaction of the pesticide with the two polymers. By means of the voltammetric response of the polymers, the carbon paste electrode modified with polianiline showed to be very suitable for the detection of the herbicide 2,4-D, bentazon and gliphosate, but not for paraquat and methilparathion. On the other hand the carbon paste electrode modified with polipirrol detect only the gliphosate and paraquat. The results shows that the detection of the paraquat and the gliphosate by the polipirrol are not influenced by protonation, whereas the detection of the 2,4-D, bentazon and gliphosate by the polianiline are due to sorption and consequent doping of the polymer by the pesticides, which have acidic behavior. The BIA technique used for the detection of the pesticide paraquat, showed a good sensitivity and could be used in the future for the analysis of such substances with many advantages when compared with conventional electroanalytical procedures.

"The goals of this study were (1) to evaluate the impacts of pesticides used for mosquito control on drinking water and (2) to investigate the removal of permethrin from water using activated carbon. A review of current literature on pesticide usage, toxicity, occurrence in the environment, and treatment techniques to remove pesticides from drinking water was conducted. The focus of the literature review was on pesticides used for mosquito control. Permethrin is a synthetic pyrethroid insecticide used extensively in the United States (US) for mosquito control and in agriculture, with approximately 2 million pounds applied each year. Permethrin was selected for investigation based on its widespread use in the US, its inclusion on the Contaminant Candidate List 3 (CCL3), its health hazards, and the lack of previous research on the removal of permethrin from drinking water. The removal of permethrin from water using powdered activated carbon (PAC) was investigated. Equilibrium adsorption experiments to assess removal of cis-, trans-, and total permethrin were conducted using two types of PAC (WPH 650 and WPH 1000). Initial total permethrin concentrations ranged from 2.0 to 4.6 ug/L. PAC doses ranged from 0.0 to 10 mg/L. Results showed that PAC addition is an effective method for removing permethrin from water. Total permethrin concentrations were reduced by 38% with 0.05 mg/L of PAC WPH 650, and reduced to below the detection limit with 3 mg/L of PAC WPH 650. Total permethrin concentrations were reduced by 35% with 0.05 mg/L of PAC WPH 1000 and by 83% with 5 mg/L of PAC WPH 1000. Results for cis- and trans- permethrin were similar. The Freundlich isotherm model provided appropriate fits to the data with an R-squared value of 0.91 for both WPH 650 and WPH 1000."

A aplicação de agrotóxicos na produção agrícola se relaciona com várias áreas do conhecimento, com destaque para a saúde pública, devido aos riscos envolvidos. No Brasil o uso indiscriminado, faz com que o país lidere, desde o ano de 2008, o consumo dessa classe de produtos. O objetivo geral do trabalho foi estimar a ingestão crônica de agrotóxicos pela população brasileira por meio da dieta, destacando as substâncias com maior consumo e suas implicações toxicológicas. Para este fim foram utilizados os alimentos registrados no bloco de consumo alimentar da Pesquisa de Orçamentos Familiares 2008-2009, conduzida pelo IBGE, e a exposição foi estimada pelo cálculo de Ingestão Diária Máxima Teórica (IDMT). A caracterização do risco foi realizada pela comparação da IDMT com os valores da Ingestão Diária Aceitável (IDA), estipuladas em mg/kg peso corporal/dia sendo aplicado o peso individual dos integrantes da amostra (n=33.613) da POF (bloco de consumo alimentar). Foram elaboradas analises discriminando a população brasileira, de acordo com as grandes regiões e situação domiciliar (urbana ou rural). Dos 283 agrotóxicos considerados para a pesquisa, 68 compostos excederam ao valor da IDA. O composto brometo de metila ocupou a primeira posição como composto com maior consumo estimado para a população brasileira. Este agrotóxico é classificado como extremamente tóxico, e seu uso está em descontinuação global por causar danos à camada de ozônio, além dos riscos à saúde de trabalhadores rurais e moradores de regiões próximas às áreas de produção agrícola. Quando estudadas as grandes regiões do país, as regiões Norte (59 agrotóxicos), Nordeste (62 agrotóxicos) e Sul (48 agrotóxicos) apresentaram um menor numero de agrotóxicos extrapolando aos valores da IDA, em comparação com o total identificado para a população brasileira (n= 68). Já as regiões sudeste e centro-oeste apresentaram número superior de compostos que extrapolaram ao valor da IDA, sendo um total de 69 compostos para ambas as regiões. Também foi estudada a exposição nos setores urbano e rural, sendo constatado que 67 compostos excederam ao valor da IDA em ambas as situações domiciliares. Para a área rural os riscos envolvidos se relacionam com a aplicação destes produtos, configurando risco de intoxicação aguda. É importante considerar que a caracterização do risco crônico será mais próxima da realidade quanto melhor os dados refletirem as condições do alimento no momento do consumo. Com isso, é recomendável a realização de estudos sobre a exposição aos agrotóxicos para a população brasileira, principalmente quanto às implicações toxicológicas, e considerando os grupos mais vulneráveis. / The application of pesticides in agricultural production is related to several areas of knowledge, with emphasis on public health, due to the risks involved. In Brazil, the indiscriminate use has led the country to lead, since 2008, the consumption of this class of products. The general objective of the study was to estimate the chronic intake of pesticides by the Brazilian population through diet, highlighting the substances with the highest consumption and their toxicological implications. For this purpose, the foods registered in the food consumption block of the Family Budget Survey 2008-2009, conducted by IBGE, were used and the exposure was estimated by the calculation of Theoretical Maximum Daily Intake (IDMT). The risk characterization was performed by comparing the IDMT with the values of Acceptable Daily Intake (ADI), stipulated in mg / kg body weight / day, and the individual weight of the sample members (n = 33,613) of POF to feed. Analyzes were carried out discriminating the Brazilian population, according to the major regions and domiciliary situation (urban or rural). Of the 283 pesticides considered for the research, 68 compounds exceeded the ADI value. The methyl bromide compound occupied the first position as the compound with the highest consumption estimated for the Brazilian population. This pesticide is classified as extremely toxic, and its use is in global discontinuation for causing damage to the ozone layer, in addition to the health risks of rural workers and residents of regions near the agricultural production areas. When the major regions of the country were studied, the North (59 pesticides), Northeastern (62 pesticides) and South (48 agrochemicals) regions presented a lower number of agrochemicals than those identified for the Brazilian population (N = 68). On the other hand, the southeastern and central-western regions presented a higher number of compounds that extrapolated to the value of the ADI, being a total of 69 compounds for both regions. Exposure in the urban and rural sectors was also studied, and it was found that 67 compounds exceeded the ADI value in both domiciliary situations. For the rural area the risks involved are related to the application of these products, posing the risk of acute intoxication. It is important to consider that the characterization of chronic risk will be closer to reality the better the data reflect the conditions of the food at the time of consumption. Therefore, it is advisable to carry out studies on exposure to pesticides for the Brazilian population, mainly regarding the toxicological implications, and considering the most vulnerable groups.

In soils spiked with gamma-HCH & DDT, and transplanted with wheat, the differences of gamma-HCH between the rhizosphere and non-rhizosphere soils increased with time, reached the peak on 30th sampling day, and then decreased with time. In the rhizosphere and non-rhizosphere soils, pp'-DDE/SigmaDDTs, op'-DDD/SigmaDDTs and pp'-DDD/SigmaDDTs increased with time; whilst op'-DDT/SigmaDDT and pp'-DDT/SigmaDDT decreased with time. The wheat, corn and soybean rhizosphere soils differed greatly in soil properties, but it was hard to conclude the effect of crop roots on the variation in concentration of gamma-HCH, p,p'-DDE, p,p'-DDD and p,p'-DDT in the rhizosphere soils except for root accumulation and translocation. / In the control, wheat and corn rhizosphere soils, the n-hexane extracted fraction of gamma-HCH, DDE, DDD and DDT decreased with time whereas the hexane/acetone extracted fraction increased with time after the 20th sampling day. The n-hexane extracted forms were higher in the rhizosphere soils than those in the non-rhizosphere soils, while the hexane/acetone extracted forms were lower in the rhizosphere soils than in the non-rhizosphere soils. / In the wheat, corn rhizosphere soils and the control, the concentration of NO3-N showed a significant negative correlation with n-hexane extracted DDE, DDD and DDT residues and a significant positive correlation with hexane/acetone extracted residues. The concentration of ammonium nitrogen (NH4-N) showed a significant negative correlation with hexane extracted gamma-HCH, DDE, DDD and DDT residues in the control, corn and wheat rhizosphere soils: but only had significant positive correlation with the n-hexane/acetone extracted fraction in the corn rhizosphere soil. The positive correlations between the n-hexane extracted residues of the target pesticides and soil OC were seldom significant in the control, sometimes significant in the wheat rhizosphere soils, and always strong and significant in the corn rhizosphere soils. The correlation of the n-hexane/acetone extracted residues with soil OC was positive and sometimes significant in the wheat rhizosphere soils, and significant and negative in the corn rhizosphere soils. The results indicated that the concentrations of different OCPs extracted from were strongly influenced by nutritional conditions and soil organic carbon. / Organic carbon (OC), dissolved organic carbon (DOC) and cultivation period were tested to explore their potential effects on target OCPs in the rhizosphere soils. The concentration of the target OCPs in the wheat rhizosphere soils increased proportionally to soil OC, whilst the uptake of OCPs by wheat roots and further translocation to the aboveground part were inversely proportional to soil OC. DOC only showed a negative correlation with concentration of p,p'-DDE and p,p'-DDT in the corn rhizosphere soils. After a longer root-soil interaction, roots had a more significant effect on the concentration of OCPs in the rhizosphere soils closer to the root surface. / The variation of different forms of OCPs in rhizosphere soils and their relationships with nitrogen nutrients and organic carbon were studied. / Variations in concentrations of organochlorine pesticide (OCP) residues in the rhizosphere soils were evaluated using rhizoboxes. A sequential extraction method was developed to study the fractionation and extractability of OCPs in rhizosphere soils. The key findings are as follows: / Zhu Xuemei. / "September 2006." / Adviser: Kin Che Lam. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1532. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 265-288). / 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.

by Wai Lok Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 142-155). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstracts --- p.ii / Contents --- p.vii / List of figures --- p.xiii / List of tables --- p.xvi / Abbreviations --- p.xviii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Pentachlorophenol / Chapter 1.1.1 --- Applications of pentachlorophenol --- p.1 / Chapter 1.1.2 --- Characteristics --- p.3 / Chapter 1.1.3 --- Pentachlorophenol in the environment --- p.3 / Chapter 1.1.4 --- Toxicity of Pentachlorophenol --- p.6 / Chapter 1.2 --- Treatments of Pentachlorophenol --- p.10 / Chapter 1.2.1 --- Physical treatment --- p.10 / Chapter 1.2.2 --- Chemical treatment --- p.11 / Chapter 1.2.3 --- Biological treatment --- p.13 / Chapter 1.3 --- Biodegradation --- p.14 / Chapter 1.3.1 --- Biodegradation of PCP by bacteria --- p.14 / Chapter 1.3.2 --- Biodegradation of PCP by white-rot fungi --- p.15 / Chapter 1.4 --- Biosorption --- p.24 / Chapter 1.5 --- Proposed Strategy --- p.28 / Chapter 1.6 --- Spent Mushroom Compost / Chapter 1.6.1 --- Background --- p.28 / Chapter 1.6.2 --- Physico-chemical properties of SMC --- p.29 / Chapter 1.6.3 --- As a biosorbent --- p.29 / Chapter 1.6.3.1 --- Factors affecting biosorption --- p.31 / Chapter 1.6.3.2 --- Contact time --- p.31 / Chapter 1.6.3.3 --- Initial pH --- p.32 / Chapter 1.6.3.4 --- Concentration of biosorbent --- p.33 / Chapter 1.6.3.5 --- Initial PCP concentration --- p.34 / Chapter 1.6.3.6 --- Incubation temperature --- p.34 / Chapter 1.6.3.7 --- Agitation speed --- p.35 / Chapter 1.6.4 --- Modeling of adsorption --- p.36 / Chapter 1.6.4.1 --- Langmuir isotherm --- p.36 / Chapter 1.6.4.2 --- Freundlich isotherm --- p.36 / Chapter 1.6.5 --- As a source of PCP-degrading bacteria --- p.38 / Chapter 1.6.5.1 --- Identification of PCP-degrading bacterium --- p.40 / Chapter 1.6.6 --- As a source of fungus --- p.42 / Chapter 1.7 --- Objectives of this Study --- p.43 / Chapter 2. --- Materials and Methods --- p.44 / Chapter 2.1 --- Spent Mushroom compost (SMC) Production --- p.44 / Chapter 2.2 --- Characterization of SMC --- p.46 / Chapter 2.2.1 --- pH --- p.46 / Chapter 2.2.2 --- Electrical conductivity --- p.46 / Chapter 2.2.3 --- "Carbon, hydrogen, nitrogen and sulphur contents" --- p.46 / Chapter 2.2.4 --- Infrared spectroscopic study --- p.47 / Chapter 2.2.5 --- Metal analysis --- p.47 / Chapter 2.2.6 --- Anion content --- p.47 / Chapter 2.2.7. --- Chitin assay --- p.48 / Chapter 2.3 --- Extraction of PCP --- p.49 / Chapter 2.3.1 --- Selection of extraction solvent --- p.49 / Chapter 2.3.2 --- Selection of desorbing agent --- p.49 / Chapter 2.3.3 --- Extraction efficiency --- p.50 / Chapter 2.4 --- Adsorption of Pentachlorophenol on SMC --- p.50 / Chapter 2.4.1 --- Preparation of pentachlorophenol (PCP) stock solution --- p.50 / Chapter 2.4.2 --- Batch adsorption experiment --- p.51 / Chapter 2.4.3 --- Quantification of PCP by HPLC --- p.51 / Chapter 2.4.4 --- Data analysis for biosorption --- p.51 / Chapter 2.4.5 --- Optimization of PCP adsorption --- p.52 / Chapter 2.4.5.1 --- Effect of contact time --- p.52 / Chapter 2.4.5.2 --- Effect of initial pH --- p.52 / Chapter 2.4.5.3 --- Effect of incubation temperature --- p.53 / Chapter 2.4.5.4 --- Effect of shaking speed --- p.53 / Chapter 2.4.5.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.53 / Chapter 2.4.6 --- Adsorption isotherm --- p.53 / Chapter 2.4.7 --- Effect of removal efficiency on reuse of biosorbent --- p.54 / Chapter 2.5 --- Biodegradation by Isolated Bacterium --- p.54 / Chapter 2.5.1 --- Isolation of PCP-tolerant bacteria from mushroom compost --- p.54 / Chapter 2.5.2 --- Screening for the best PCP-tolerant bacterium --- p.54 / Chapter 2.5.3 --- Identification of the isolated bacterium --- p.55 / Chapter 2.5.3.1 --- 16S ribosomal DNA sequencing --- p.55 / Chapter 2.5.3.1.1 --- Extraction of DNA --- p.55 / Chapter 2.5.3.1.2 --- Specific PCR for 16S rDNA --- p.56 / Chapter 2.5.3.1.3 --- Gel electrophoresis --- p.57 / Chapter 2.5.3.1.4 --- Purification of PCR products --- p.57 / Chapter 2.5.3.1.5 --- Sequencing of 16S rDNA --- p.58 / Chapter 2.5.3.2 --- Gram staining --- p.60 / Chapter 2.5.3.3 --- Biolog Microstation System --- p.60 / Chapter 2.5.3.4 --- MIDI Sherlock Microbial Identification System --- p.61 / Chapter 2.5.4 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.62 / Chapter 2.5.4.1 --- Effect of incubation time --- p.63 / Chapter 2.5.4.2 --- Effect of shaking speed --- p.63 / Chapter 2.5.4.3 --- Effect of initial PCP concentration and inoculum size --- p.63 / Chapter 2.5.4.4 --- Study of PCP degradation pathway by isolated bacterium using GC-MS --- p.64 / Chapter 2.6 --- Biodegradation by Fungus Pleurotus pulmonarius --- p.64 / Chapter 2.6.1 --- Optimization of PCP degradation by P. pulmonarius --- p.65 / Chapter 2.6.1.1 --- Effect of incubation time --- p.65 / Chapter 2.6.1.2 --- Effect of shaking speed --- p.65 / Chapter 2.6.1.3 --- Effect of initial PCP concentration and inoculum size --- p.65 / Chapter 2.6.2 --- Study of PCP degradation pathway by fungus using GC-MS --- p.65 / Chapter 2.6.3 --- Specific enzyme assays --- p.66 / Chapter 2.6.3.1 --- Extraction of protein and enzymes --- p.66 / Chapter 2.6.3.2 --- Protein --- p.66 / Chapter 2.6.3.3 --- Laccase --- p.67 / Chapter 2.6.3.4 --- Manganese peroxidase (MnP) --- p.67 / Chapter 2.6.4 --- Microtox® assay --- p.67 / Chapter 2.7 --- Statistical Analysis --- p.68 / Chapter 3. --- Results --- p.69 / Chapter 3.1 --- Physico-chemical Properties of SMC --- p.69 / Chapter 3.2 --- Extraction Efficiency and Desorption Efficiency of PCP --- p.69 / Chapter 3.3 --- Batch Adsorption Experiments --- p.76 / Chapter 3.3.1 --- Optimization of adsorption conditions --- p.76 / Chapter 3.3.1.1 --- Effect of contact time --- p.76 / Chapter 3.3.1.2 --- Effect of initial pH --- p.76 / Chapter 3.3.1.3 --- Effect of shaking speed --- p.79 / Chapter 3.3.1.4 --- Effect of incubation temperature --- p.79 / Chapter 3.3.1.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.79 / Chapter 3.3.2 --- Reuse of SMC --- p.83 / Chapter 3.3.3 --- Isotherm plot --- p.83 / Chapter 3.4 --- Biodegradation by PCP-degrading Bacterium --- p.86 / Chapter 3.4.1 --- Isolation and purification of PCP-tolerant bacteria --- p.86 / Chapter 3.4.2 --- Identification of the isolated bacterium --- p.90 / Chapter 3.4.2.1 --- 16S rDNA sequencing --- p.90 / Chapter 3.4.2.2 --- Gram staining --- p.90 / Chapter 3.4.2.3 --- Biolog MicroPlates Identification System --- p.90 / Chapter 3.4.2.4 --- MIDI Sherlock Microbial Identification System --- p.90 / Chapter 3.4.3 --- Growth curve of PCP-degrading bacterium --- p.90 / Chapter 3.4.4 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.97 / Chapter 3.4.4.1 --- Effect of incubation time --- p.97 / Chapter 3.4.4.2 --- Effect of shaking speed --- p.97 / Chapter 3.4.4.3 --- Effect of initial PCP concentration and inoculum size of bacterium --- p.101 / Chapter 3.4.5 --- Determination of breakdown products of PCP by PCP-degrading bacterium --- p.101 / Chapter 3.5 --- Biodegradation by Fungus Pleurotus pulmonarius --- p.103 / Chapter 3.5.1 --- Growth curve of P. pulmonarius --- p.103 / Chapter 3.5.2 --- Optimization of PCP degradation by P. pulmonarius --- p.103 / Chapter 3.5.2.1 --- Effect of incubation time --- p.103 / Chapter 3.5.2.2 --- Effect of shaking speed --- p.103 / Chapter 3.5.2.3 --- Effect of initial PCP concentration and inoculum size of fungus --- p.108 / Chapter 3.5.3 --- Determination of breakdown products of PCP by P. pulmonarius --- p.108 / Chapter 3.5.4 --- Enzyme assays --- p.108 / Chapter 3.6 --- Integration of Biosorption by SMC and Biodegradation by P. pulmonarius --- p.112 / Chapter 3.6.1 --- Evaluation of PCP removal by an integration system --- p.112 / Chapter 3.6.2 --- Evaluation of toxicity by Micortox® assays --- p.112 / Chapter 4. --- Discussion --- p.115 / Chapter 4.1 --- Physico-chemical Properties of SMC --- p.115 / Chapter 4.2 --- Extraction Efficiency and Desorption Efficiency of PCP --- p.116 / Chapter 4.3 --- Batch Biosorption Experiment --- p.117 / Chapter 4.3.1 --- Effect of contact time --- p.117 / Chapter 4.3.2 --- Effect of initial pH --- p.118 / Chapter 4.3.3 --- Effect of shaking speed --- p.120 / Chapter 4.3.4 --- Effect of incubation temperature --- p.120 / Chapter 4.3.5 --- Effect of initial PCP concentration and amount of biosorbent --- p.121 / Chapter 4.3.6 --- Reuse of SMC --- p.122 / Chapter 4.3.7 --- Modeling of biosorption --- p.122 / Chapter 4.4 --- Biodegradation of PCP by PCP-degrading Bacterium --- p.124 / Chapter 4.4.1 --- Isolation and purification of PCP-tolerant bacterium --- p.124 / Chapter 4.4.2 --- Identification of the isolated bacterium --- p.125 / Chapter 4.4.3 --- Optimization of PCP degradation by PCP-degrading bacterium --- p.126 / Chapter 4.4.3.1 --- Effect of incubation time --- p.126 / Chapter 4.4.3.2 --- Effect of shaking speed --- p.128 / Chapter 4.4.3.3 --- Effect of initial PCP concentration and inoculum size of bacterium --- p.128 / Chapter 4.4.4 --- PCP degradation pathway by S. marcescens --- p.129 / Chapter 4.5 --- Biodegradation of PCP by Pleurotus pulmonarius --- p.130 / Chapter 4.5.1 --- Optimization of PCP degradation by P. pulmonarius --- p.130 / Chapter 4.5.1.1 --- Effect of incubation time --- p.131 / Chapter 4.5.1.2 --- Effect of shaking speed --- p.131 / Chapter 4.5.1.3 --- Effect of initial PCP concentration and inoculum size of fungus --- p.131 / Chapter 4.5.2 --- Enzyme activities --- p.132 / Chapter 4.5.3 --- PCP degradation pathway by P. pulmonarius --- p.133 / Chapter 4.6 --- Comparison of PCP Degradation between S.marcescens and P. pulmonarius --- p.133 / Chapter 4.7 --- Integration of Biosorption by SMC and Biodegradation by P. pulmonarius --- p.135 / Chapter 4.8 --- Evaluation of toxicity by Microtox® assay --- p.135 / Chapter 4.9 --- Comparison of PCP Removal by Integration System of Sorption and Fungal Biodegradation and Conventional Treatments --- p.136 / Chapter 4.10 --- Further Investigations --- p.137 / Chapter 5. --- Conclusion --- p.139 / Chapter 6. --- References --- p.142

O aumento do uso de pesticidas para erradicação de pragas e ervas daninhas resultou no aumento da produção agrícola mundial, contudo, levou à preocupação sobre os impactos ambientais, sociais e econômicos decorrentes dessa prática. A microbiota nativa do solo é muito importante para manter a qualidade desse ambiente, mas com o uso intensivo de agroquímicos foram observadas alterações na biomassa microbiana e na formação de grandes quantidades de resíduos tóxicos. O presente estudo teve como objetivo avaliar o potencial genético das frações cultiváveis e não cultiváveis do solo para degradação de três diferentes herbicidas e verificar se a pressão seletiva exercida pela presença de um determinado herbicida tem potencial para alterar a composição da microbiota local, além de identificar os principais gêneros bacterianos cultiváveis da microbiota do solo portadores dos genes de degradação destes herbicidas. Para isso, foram utilizadas seis amostras de solo de diferentes regiões brasileiras, as quais foram obtidas do estado de São Paulo e de áreas de preservação ambiental dos estados do Amazonas e de Goiás. Os principais gêneros bacterianos identificados na microbiota do solo foram: Acinetobacter, Bacillus, Enterobacter, Escherichia, Leclercia, Lysinibacillus, Klebsiella e Staphylococcus e não foram observadas variações nas frações cultiváveis e não cultiváveis do solo quanto ao potencial genético para a degradação dos diferentes herbicidas utilizados.Alguns desses isolados bacterianos apresentaram os genes para a degradação de dois herbicidas (2,4-D e diuron; atrazina e diuron) e ainda isolados que apresentam potencial genético para degradação dos três herbicidas. Além disso, pela análise em HPLC acoplado a espectrometria de massas, algumas bactérias portadoras dos genes de degradação do diuron (puhA e puhB) apresentaram formação dos metabólitos DCPMU, DCPU e DCA, os quais já foram descritos na literatura e também apresentaram metabólitos que ainda não estão descritos na literatura. Por meio das análises de eletroforese em gradiente desnaturante (DGGE) foi possível observar que a pressão seletiva exercida pela presença desses herbicidas altera a composição da microbiota local e a atrazina foi o herbicida que mais afetou a comunidade bacteriana do solo. Portanto, o estudo da diversidade microbiana associada à pressão seletiva causada pelo uso de herbicidas é de grande importância, visto que os herbicidas alteram significativamente a heterogeneidade da comunidade bacteriana do solo. / The use of pesticides to eradicate pests and weeds resulted in increased agricultural production worldwide, however, led to concern about the environmental, social and economic impacts of this practice. Native soil microbiota is very important to maintain the quality of the environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste have been observed. This study aimed to evaluate the genetic potential of cultivable and non-cultivable soil fractions to degradate three different herbicides, to verify if the selective pressure exerted by the presence of a particular herbicide has the potential to change the composition of the local microbiota and to identify the main cultivable soil bacterial genera carrying these herbicides degradation genes. For this, six soil samples from different Brazilian regions were used, which were obtained from the state of São Paulo and from environmental preservation areas in the states of Amazonas and Goiás. The main bacterial genera identified in the soil microbiota were: Acinetobacter, Bacillus, Enterobacter, Escherichia, Leclercia, Lysinibacillus, Klebsiella and Staphylococcus, and variations in cultivable and non-cultivable soil fractions genetic potential to degrade various herbicides were observed. Some of these strains harbored genes for degradation of two herbicides (2,4-D and diuron; atrazine and diuron) and other isolates showed genetic potential to degrade one of the three herbicides. Furthermore, analysis with HPLC-MS showed that some bacteria carrying the diuron degradation genes (puhA and puhB) presented formation of metabolites already described in the literature, such DCPMU, DCPU and DCA, and metabolites that have not been described in the literature. By electrophoresis analysis on denaturing gradient (DGGE), was observed that the selective pressure exerted by the presence of these herbicides alters the composition of the local microbiota, being atrazine the herbicide that most affected the bacterial community in the soil. Therefore, the study of the influence of the selective pressure caused by the use of herbicides in the microbial diversity is very important, since herbicides significantly alter the heterogeneity of the soil bacterial community.

No description available.

Por muito tempo acreditou-se que o solo atuaria como um filtro protegendo os grandes reservatórios de água subterrânea. Porém estes reservatórios possuem áreas onde existe uma maior sensibilidade à contaminação da água, devido características específicas do solo e não confinamento da rocha porosa. Estes locais são conhecidos também como áreas de recarga. O Sistema Aquífero Guarani (SAG) é atualmente a reserva de água subterrânea mais importante do Brasil. Transfronteiriço, ocupa 8 estados nacionais e 3 países da América do Sul, e recebe constante impacto pelo uso da água e de suas áreas de recarga por atividades industriais e agrícolas. No estado de São Paulo, Brasil, existe uma faixa contínua e estreita de afloramento do SAG que abrange a porção central, com ocorrência de solos arenosos, baixa profundidade da rocha sedimentar e ocupação do solo com atividades agrícolas intensivas (em especial citros, café, cana-de-açúcar e silvicultura). As características edafoclimáticas influenciam diretamente a vulnerabilidade dos aquíferos, e esta pode ser medida com ajuda de ferramentas de modelagem digital associadas a Sistemas de Informações Georreferenciadas (SIG). Sendo a atividade agrícola a mais recorrente neste sistema de recarga do SAG, este projeto objetivou estudar os impactos da agricultura neste sistema em três frentes. Primeiro pela determinação da vulnerabilidade do aquífero pelo modelo DRASTIC-SIG de uma área de recarga do Aquífero Guarani ocupada com a cultura de citros e com solo arenoso. Segundo pela avaliação da ocorrência de contaminação por agrotóxicos de águas superficiais, subterrâneas e sedimento por HPLC-UV/DAD e CG-µECD. E por final, avaliando o comportamento do herbicida Diuron em solo da área de estudo. Os resultados do modelo DRASTIC apontaram alta vulnerabilidade do aquífero para a região estudada. Foi identificada contaminação pontual por Heptacloro em duas amostras de água superficial analisadas. Quanto ao comportamento do Diuron em solo, este apresentou baixo risco de lixiviação e baixa adsorção em solo arenoso. Estes resultados indicam que estas áreas devem ser mais estudadas quanto à vulnerabilidade, visando o direcionamento de políticas públicas para orientar a melhores práticas nas lavouras objetivando a proteção desta importante reserva natural de água, que está atualmente exposta às atividades antrópicas e pode ter a sua qualidade comprometida no longo tempo / For a long time it was believed that watersheds would be free of environmental contamination due protection exerted by soil and rock layers. However, aquifers may have confined areas where it is covered by one or more layers of solid rock, and not confined areas where the sedimentary rock, which retains water, is outcropping. In the non-confined areas, the aquifer is recharged usually by direct infiltration of rainwater or indirectly from other water bodies. Thus, the recharge areas have higher sensitivity and vulnerability to contamination because they are more exposed to anthropogenic activities. The Guarani Aquifer System (GAS) is currently the most important groundwater reserve in Brazil. Transboundary, it occupies 8 national states and 3 countries in South America, and receives constant impact of it is uses and soil occupation for industrial and agricultural activities. In São Paulo State, Brazil, there is a continuous narrow strip of outcrop of GAS covering the inner portion of the central part of the State, with the occurrence of sandy soils, shallow sedimentary rock and soil occupation with intensive agricultural activities (especially citrus, coffee, sugarcane and planted forestry). Soil and climatic characteristics directly influence the vulnerability of aquifers, and this can be measured with the help of digital modeling tools associated with Geo-referenced Information Systems (GIS). Due the agricultural activity being the most practiced activity in the GAS recharge system, this project aimed to study the specific impact of agriculture in the system by three fronts. First was to determine the vulnerability by DRASTIC-GIS model of a recharge area of the Guarani Aquifer occupied with the cultivation of citrus and sandy soil. Second, was the evaluation of the occurrence of pesticides contamination in surface water, groundwater and sediment by HPLC-UV/DAD and GC-µECD for the period of one year. And last, studying the Diuron behavior in the soil of the study area. The results of the DRASTIC model showed a high vulnerability of the aquifer to the region studied. Spot contamination was identified by Heptachlor in two field samples of surface water. The Diuron behavior in soil showed lowrisk of leaching and low sorption coefficient. These results indicates that these areas should be more studied for vulnerability, targeting the direction of public policies to guide best practices in the fields aiming to protect this important natural water reserve, which is currently exposed to human activities and may have their quality compromised in the long time

O presente trabalho propôs estudar as alterações microscópicas observadas em 100 casos de intoxicação por aldicarb em cães e gatos e os efeitos agudos (14 dias) induzidos por esse praguicida em camundongos após a administração de dose única oral, avaliando-se as alterações clínicas, laboratoriais, microscópicas e ultraestruturais. As principais lesões microscópicas em cães e gatos foram observadas nos pulmões (congestão, edema, hemorragia, enfisema e atelectasia), fígado (congestão, degeneração vacuolar e hemorragia) e rins (congestão, hemorragia e nefrose). Nos demais órgãos, apenas alterações circulatórias (congestão e hemorragia) foram encontradas. Em ambas espécies, considerando as alterações significantes de acordo com a faixa etária, observou-se que os animais idosos apresentaram o maior grau de intensidade de degeneração vacuolar hepática e que a congestão renal foi mais intensa nos adultos. Em camundongos, observou-se que: 1) doses superiores a 0,08 mg/kg de aldicarb promoveram a morte de todos os animais em 2,6 - 4,7 minutos após a exposição, sendo o óbito precedido por convulsões; 2) a dose de 0,08 mg/kg promoveu o rápido aparecimento dos sinais clínicos clássicos da intoxicação por anticolinesterásicos, com duração de 45 - 120 minutos, sendo esta a dose escolhida para os demais experimentos in vivo; 3) os camundongos expostos mostraram consumo de água superior ao do grupo controle até o 5° dia após a exposição e inferior a partir do 10° dia até o término do experimento (14º dia); 4) quanto ao consumo de ração, de forma geral, camundongos expostos ao praguicida consumiram menos que os não expostos, sendo o ganho de peso inferior ao do grupo controle nas primeiras 48 horas após a intoxicação; 5) as alterações histopatológicas, como observado em cães e gatos, ocorreram principalmente nos pulmões (edema, congestão e hemorragia), fígado (congestão e degeneração vacuolar, principalmente em zona 3) e rins (congestão, hemorragia e nefrose), sendo que as alterações degenerativas em fígado e rins foram significantemente mais intensas até 48 horas após a exposição; 6) na avaliação ultraestrutural (microscopia eletrônica de transmissão) após 24 e 48 horas da exposição, foi observada a presença de tumefação celular e mitocondrial e, após 48 horas, a presença de vacúolos citoplasmáticos hepáticos, os quais continham gordura pela avaliação histoquímica; nos rins foram observadas também desorganização, tumefação e despregamento celulares, além da presença de conteúdo intratubular; 7) os principais achados do hemograma foram a diminuição no número de hemácias após 24 horas da exposição e leucopenia, que persistiu ate o 7° dia da intoxicação; 8) entre as alterações bioquímicas relevantes estão o aumento da glicemia e da amilase após 24 horas da exposição, bem como dos triglicerídeos e da creatinina até 48 horas após o quadro agudo; 9) os principais achados nos ensaios de imunotoxicidade foram o aumento do peso relativo do timo e da celularidade do baço, bem como a diminuição da celularidade da medula óssea nas primeiras 48 horas após a exposição; 10) avaliando-se a indução de morte celular por apoptose e/ou necrose pelo aldicarb em hepatócitos e leucócitos in vitro, constatou-se que o aldicarb promove tanto apoptose quanto necrose de leucócitos de camundongos e que é capaz de aumentar a porcentagem de hepatócitos com apoptose, tanto in vivo quanto in vitro. Tomando-se estes resultados em conjunto, foi possível constatar que a exposição oral aguda grave ao aldicarb produz efeitos nocivos graves, principalmente nos pulmões, fígado, rins, pâncreas e sistema imune, notadamente nas primeiras 48 horas após a exposição. / The present study evaluated microscopic post mortem findings in 100 cases of aldicarb intoxication in dogs and cats and the acute toxicity in mice induced by a single dose of aldicarb, assessing the clinical, laboratorial, microscopic and ultrastructural alterations caused by aldicarb up to 14 days after exposition. The most commonly affected organs in dogs and cats were lung (congestion, edema, hemorrhage, emphysema and/or atelectasy), liver (congestion, vacuolar degeneration and/or hemorrhage) and kidney (congestion, hemorrhage and/or nephrosis); the other organs showed circulatory alterations, as congestion and hemorrhage. Considering both species and age we observed that old animals had the most intensity of hepatic vacuolar degeneration and the adult animals the most intensity of renal congestion. Experimental oral aldicarb poisoning resulted in death if mice were exposed to more than 0.08mg/kg, preceded by seizures. Rapid and classical symptoms of anticholinesterase poisoning occurred within 45 minutes to 2 hours after exposure to 0.08mg/kg of oral aldicarb. Animals exposed to 0.08mg/kg of aldicarb presented increased water intake until day 5, followed by decreased water intake from day 10 to day 14 after exposure to the drug in comparison to control animals. Food intake was also decreased in the experimental group. Blood analyses revealed decreased erythrocyte count and leukopenia started 24 hours after exposure and persistent for 7 days. Hyperglycemia, hypertriglyceremia, elevation of amylase and creatinine happened after 24 to 48 hours after exposure. Microscopic evaluation revealed: (i) lung edema, pulmonary congestion and/or pulmonary hemorrhage; (ii) liver congestion and zonal vacuolar degeneration of the liver; (iii) renal congestion, nephrosis and/or kidney hemorrhage. Those alterations were more prominent after 24 to 48 hours of exposure to aldicarb. Ultrastructural analysis (transmission electron microscopy) demonstrated: (i) cellular edema and mitochondrial swelling after 24 and 48 hours after exposure to aldicarb; (ii) lipid vacuoles in hepatocytes after 48 hours of exposure; (iii) renal tubular epithelium disorganization with swelling and intratubular cell exfoliation. Increased thymus/body weight ratio and spleen cellularity and decreased bone marrow cellularity were also found after 48 hours of aldicarb exposure. Aldicarb was able to induce leukocyte dead by necrosis and/or apoptosis in vitro and hepatocyte apoptosis in vivo and in vitro. Altogether, our findings demonstrated that acute oral exposure to aldicarb induces toxic effects mainly to the lungs, liver, kidneys, pancreas, and immune system. Those effects are more evident up to 48 hours after intoxication.