Ces travaux voulaient démontrer que l'hydrolyse d'herbicides dans le sol, l'hiver comme l'été, est catalysée par l'acidité de surface des minéraux argileux. Le manque d'eau pouvant limiter la réaction, l'hydrolyse a d'abord été étudiée dans l'eau. La demi-vie d'hydrolyse acide du diuron dans l'eau a été estimée à 320 et 5,2 ans, à 0 et 22 °C respectivement, entre pH 1 et -1 où la vitesse de la réaction plafonne. Par contre en 16 semaines, la quantité initiale d'atrazine ou de simazine dans l'eau est réduite de 20 % à pH 2,0 à 0 °C, et 3,3 à 22 °C. Une nouvelle équation, basée sur la fonction acide Ho plutôt que le pH, impliquant les triazines neutre, mono-, di- et triprotonées, a été proposée pour prédire la demi-vie en solutions très acides. Deux pellicules plastiques, l'une en polyethylene basse densité (LDPE), l'autre en chlorure de polyvinyle (PVC) plastifié, ont été testées comme support transparent dans l'UV-Visible de films minces d'argile imprégnés d'herbicide. Le LDPE absorbe moins dans cette région spectrale. Sa faible polarité entraîne toutefois de sérieux problèmes d'étalement et d'adhésion de l'argile. Le PVC libère du HCl(g), mais en quantité négligeable et limitée à 21 °C. L'hydrolyse acide de l'atrazine et du diuron à la surface de films d'argile supportés par la pellicule de PVC, a été étudiée à -4 et 21 °C, par spectroscopie UV-Visible de transmission. Les formes -K, -Ca, -Mg, -Zn, -Fe, -Al et -H de deux smectites et d'une vermiculite ont été préparées. Les argiles homoioniques déshydratées à l'air libre n'ont montré aucune activité catalytique vis-à-vis des herbicides en 16 semaines, à l'exception de la montmorillonite-H où l'atrazine est protonée au-dedans de 24 heures. Cette réactivité s'explique seulement par l'accessibilité de l'atrazine neutre à l'espace interfoliaire de la montmorillonite-H, et l'acidité de surface particulièrement élevée de celle-ci. L'atrazine n'est pas hydrolysée sur la montmorillonite-H en raison de l'insuffisance d'eau disponible. L'absence de protonation de l'atrazine sur les autres argiles, lorsque l'ouverture des feuillets permet son accès, découle de leur trop forte teneur en eau résiduelle. Le diuron ne pénètre pas dans l'espace interfoliaire des argiles.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-27T13:41:48Z No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-27T19:51:56Z (GMT) No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-27T19:52:06Z (GMT) No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Made available in DSpace on 2016-09-27T19:52:15Z (GMT). No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) Previous issue date: 2016-03-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The aim of this study was to evaluate the effects of diuron and carbofuran, isolated and mixed, on Raphidocelis subcapitata, Paramecium caudatum and Ceriodaphnia silvestrii and carry out a preliminary risk assessment of these pesticides for Brazilian water bodies. For this, acute and chronic toxicity tests were performed with individual compounds and in combination, in its standard form and commercial formulations. The results showed that in individual action, these pesticides significantly inhibited the R. subcapitata population growth and caused physiological (chlorophyll a content) and morphological (complexity and cell size) changes in the cells. For this alga, the toxicity of standard active ingredients and their commercial formulations showed no significant differences. For the protozoan P. caudatum, acute toxicity tests evidenced an increase of mortality with increasing exposure time for the selected compounds. Moreover, these pesticides caused a significant decrease in population growth, number of generations and biomass of P. caudatum. The toxicity of standard diuron and its commercial formulation was similar for this protozoan, while commercial carbofuran was more toxic than its standard form, suggesting a synergistic interaction with “inert” ingredients. In contrast, for the cladoceran C. silvestrii, acute toxicity tests showed that diuron commercial product was 7.2 times more toxic than its standard active ingredient, whereas for carbofuran, commercial product was 1.5 times less toxic than its standard active ingredient. Regarding chronic toxicity of diuron herbicide, both standard and commercial form caused hormetic effects on fertility of C. silvestrii female. Carbofuran significantly reduced the reproduction of C. silvestrii at concentrations from 0.38 μg L-1 onwards. The tropical species C. silvestrii was more sensitive to these pesticides than cladocerans commonly used in temperate regions, and in addition, for carbofuran, this species was the most sensitive organism already tested (EC50-48h = 0,86 μg L-1). According to the toxicity tests results of diuron and carbofuran mixtures, acute and chronic exposures on all selected test organisms caused significant deviations from the toxicity predicted by Concentration Addition and Independent Action reference models. For P. subcapitata, data indicated the occurrence of synergism in the mixture of these compounds, especially when diuron is the dominant chemical in combination. For P. caudatum, dose ratio dependent deviation (synergism caused by carbofuran and antagonism caused by diuron) was observed in acute exposure and deviation for antagonism was verified for population growth at sublethal concentrations of the standard compounds mixtures. For C. silvestrii, antagonism was observed in low doses and synergism at high doses, predominating synergism in acute exposures of standard pesticides mixtures, while for reproduction the deviation for antagonism was found. The commercial product mixtures of diuron and carbofuran showed significantly different effects and more severe than the standard compounds mixtures for P. caudatum and C. silvestrii. Therefore, diuron and carbofuran mixture can interact and cause toxic responses different from those predicted for individual compounds. According to the concentrations found in water bodies in Brazil, these compounds can cause direct and indirect toxic effects on communities of algae, protozoa and cladocerans and may change the structure and functioning of aquatic ecosystems. In a preliminary risk assessment of these pesticides, risk quotients were larger than 1, indicating that diuron and carbofuran represent potential ecological risks to Brazilian water bodies. Given the above, it is concluded that the pesticides studied alone and in combination, caused toxicity to test organisms and represent potential ecological risk for aquatic environments, which suggests the implementation by the regulatory agencies of more stringent measures for the use of pesticides to improve the protection of aquatic biota. / O objetivo desta pesquisa foi avaliar os efeitos do diuron e do carbofuran, isolados e em mistura, sobre as espécies Raphidocelis subcapitata, Paramecium caudatum e Ceriodaphnia silvestrii e realizar uma avaliação de risco preliminar destes agrotóxicos para os corpos d’água brasileiros. Para isso, testes de toxicidade aguda e crônica foram realizados com os compostos isolados e em mistura, nas suas formas padrão e comercial. Os resultados mostraram que, em ação individual, estes agrotóxicos inibiram significativamente o crescimento populacional de R. subcapitata e causaram alterações fisiológicas (conteúdo de clorofila a) e morfológicas (complexidade e tamanho celular) nas células. Para esta espécie de alga, a toxicidade dos ingredientes ativos nas formas padrão e comercial não apresentaram diferenças significativas. Para o protozoário P. caudatum, os testes de toxicidade aguda evidenciaram um aumento da mortalidade com o aumento do tempo de exposição aos compostos selecionados. Além disso, estes agrotóxicos causaram uma diminuição significativa no crescimento populacional, no número de gerações e na biomassa de P. caudatum. A toxicidade do diuron padrão e de sua formulação comercial foi similar para este protozoário, enquanto que o carbofuran comercial foi mais tóxico do que a sua forma padrão, sugerindo a ocorrência de interações sinérgicas com os ingredientes “inertes”. Diferentemente, para o cladócero C. silvestrii, os testes de toxicidade aguda mostraram que o produto comercial de diuron foi 7,2 vezes mais tóxico do que o seu ingrediente ativo padrão, enquanto que para o carbofuran, o produto comercial foi 1,5 vezes menos tóxico do que o seu ingrediente ativo padrão. Em relação à toxicidade crônica, o herbicida diuron, tanto na forma padrão como comercial, causou efeitos horméticos sobre a fertilidade das fêmeas de C. silvestrii. Já o carbofuran reduziu significativamente a reprodução de C. silvestrii em concentrações a partir de 0,38 μg L-1. A espécie tropical C. silvestrii foi mais sensível a estes agrotóxicos do que cladóceros comumente utilizados em regiões temperadas, e além disso, para o carbofuran, esta espécie foi o organismo-teste mais sensível já registrado na literatura (CE50-48h = 0,86 μg L-1). De acordo com os resultados dos testes de toxicidade das misturas de diuron e carbofuran, exposições agudas e crônicas sobre todos os organismos-teste selecionados causaram desvios significativos da toxicidade prevista pelos modelos de referência de Adição de Concentração e Ação Independente. Para a alga R. subcapitata, os dados evidenciaram a ocorrência do sinergismo na mistura destes compostos, principalmente quando o diuron é o produto químico dominante na mistura. Para o P. caudatum, o desvio dependente da proporção da dose (sinergismo causado pelo carbofuran e antagonismo causado pelo diuron) foi observado em exposições agudas e desvio para o antagonismo foi verificado para o crescimento populacional em concentrações subletais das misturas dos compostos padrões. Para a C. silvestrii, observou-se o antagonismo em baixas doses e o sinergismo em altas doses, prevalecendo o sinergismo nas exposições agudas das misturas dos agrotóxicos padrões, enquanto que para a reprodução foi encontrado o desvio para o antagonismo. As misturas dos produtos comerciais de diuron e carbofuran apresentaram efeitos significativamente diferentes e mais graves do que as misturas dos compostos padrões para o P. caudatum e a C. silvestrii. Portanto, diuron e carbofuran em mistura podem interagir e causar respostas tóxicas diferentes das previstas para os compostos individuais. De acordo com as concentrações encontradas nos corpos d’água brasileiros, estes compostos podem causar efeitos tóxicos diretos e indiretos sobre as comunidades de algas, protozoários e cladóceros, podendo alterar a estrutura e o funcionamento dos ecossistemas aquáticos. Na avaliação de risco preliminar destes agrotóxicos, os quocientes de risco foram maiores do que 1, indicando que o diuron e o carbofuran representam riscos ecológicos potenciais para os corpos d’água brasileiros. Diante do exposto, conclui-se que os agrotóxicos estudados, isolados e em mistura, causaram toxicidade aos organismos avaliados e representam riscos ecológicos potenciais para os ambientes aquáticos, o que sugere a implantação pelas agências reguladoras de medidas mais restritivas para o uso destes agrotóxicos, visando uma melhor proteção da biota aquática.

A adição de lodo de esgoto ao solo pode modificar o comportamento dos pesticidas. Sua degradação pode ser favorecida quando materiais orgânicos são adicionados ao solo, já que estes fornecem nutrientes e energia aos microrganismos capazes de degradar a molécula (Felsot & Dzantor, 1990). Por outro lado, solos ricos em matéria orgânica apresentam maior capacidade de retenção, diminuindo o potencial de lixiviação e a biodisponibilidade dos pesticidas às plantas e aos microrganismos. Nesse contexto, esta pesquisa objetivou avaliar o efeito do lodo de esgoto na biodegradação, sorção e dessorção do herbicida diuron em dois Latossolos. A biodegradação foi avaliada semanalmente, durante 63 dias, pelo método da radiorespirometria, sob condições controladas de umidade e temperatura. Ao final do período de incubação, a molécula original e os metabólitos formados foram extraídos e quantificados. Utilizou-se delineamento experimental inteiramente casualizado, em esquema fatorial 2(solos) x 3 (doses de lodo de esgoto: 0, 10 e 20 t ha-1). Paralelo ao ensaio de biodegradação, foram avaliadas a atividade e biomassa microbiana utilizando os mesmos tratamentos usados no ensaio de biodegradação, porém com dois fatores para o herbicida (com e sem herbicida). A atividade microbiana foi avaliada semanalmente e a biomassa foi avaliada no início e após 63 dias de incubação. Posteriormente, a sorção e adessorção foram avaliadas utilizando o método"Batch", o herbicida foi aplicado, em cinco concentrações, na mistura solo + lodo sem incubação e após um período de incubação de 63 dias. Utilizou-se delineamento experimental inteiramente casualizado, em esquema fatorial 2(solos) x 3 (doses de lodo de esgoto: 0, 10 e 20 ton ha-1) x 2 (sem incubação e após 63 dias de incubação). Os resultados mostraram que a biodegradação e a dessorção foram diminuídas nos solos tratados com lodo de esgoto, enquanto a sorção e formação de resíduo ligado foram maiores nestes solos. A atividade e biomassa microbiana não foram afetadas pela adição do resíduo. Estes resultados evidenciam que a adição de lodo de esgoto ao solo pode reduzir a eficiência agronômica do diuron e aumentar sua persistência no ambiente, devido a maior retenção da molécula nos solos tratados com o resíduo. / Adding sludge to agricultural soil may modify the behavior of pesticides in the soil. In some cases, the application of organic amendment increases the degradation of pesticides, by providing nutrients and energy to the microorganisms able to degrade the molecule (Felsot & Dzantor, 1990), in other cases, the sorption is increased, resulting in the decrease of leaching potential of the molecule, and smaller bioavailability of the pesticide to the plants and to the microorganisms. In this context, the aim of this work was to evaluate the effect of the sewage sludge on the biodegradation of the diuron herbicide in 2 oxisoils. The biodegradation was evaluated weekly, for 63 days, by methods of the radiorespirometry, under controlled condition of the humidity and temperature. At the end of the incubation, the original compounds and their metabolites were extracted and quantify. Completely randomized design was used with a factorial experiment of 2 (soil ) x 3 (sewage sludge: 0, 10 e 20 ton ha-1). In parallel to this study, were evaluated the microbial activity and biomass, using the same treatments of the biodegradation experiment, but with two factories for herbicide (with and without herbicide).

Orientador: Eduardo Alves de Almeida / Coorientador: Daniel Schlenk / Banca: Claudia Bueno dos Reis Martinez / Banca: Gisela de Aragão Umbuzeiro / Banca: Larissa Paola Rodrigues Venancio / Banca: Igor Dias de Medeiros / Resumo: O Brasil é o principal produtor de cana-de-açúcar do mundo e, para que esta demanda seja suprida, muitos compostos químicos são aplicados nas culturas, visando controlar o surgimento e proliferação de pragas. Assim, faz-se o uso dos praguicidas, dentre eles, o diuron (N-(3,4-diclorofenil)-N,N-dimetiluréia), que é aplicado em plantações ao redor do mundo. O diuron pode ser biodegradado em outros três principais compostos o 3,4-dicloroanilina (DCA), 3,4-diclorofenilureia (DCPMU) e 2,4-diclorofenil-N-metilureia (DCPMU). Normalmente, o diuron é aplicado nas plantações juntamente com os alquilfenóis etoxilatos (APE), como o nonilfenol etoxilato (NPE) e o octilfenol etoxilato (OPE), compostos que facilitam a dispersão do diuron. Alguns estudos têm demonstrado que tanto o diuron quanto os alquilfenóis podem causar alterações enzimáticas e/ou estrogênicas em diversos organismos. Dentre as enzimas que podem ser alteradas, estão as enzimas de biotransformação, tanto de fase I (7-etoxirresorufina-O-deetilase - EROD, 7-pentóxiresorufinaO-desalquilase - PROD, 7-benzilóxiresorufina-O-desalquilase - BROD e a P450 aromatase), quanto as de fase II (glutationa-S-transferase - GST) e as proteínas de fase III (resistência a multixenobioticos - MXR). Outros parâmetros que podem sofrer alterações são os antioxidantes (superóxido dismutase - SOD, catalase - CAT, glutationa peroxidase - GPx, glutationa redutase - GR, glutationa-6-fosfato desidrogenase - G6PDH, aldeído desidrogenase - ALDH e... / Abstract: Brazil is the main sugar cane producer in the world, and to support these productions many chemical compounds have being apply in agriculture, aiming to control the appearance and proliferation of pests. Therefore, the use of pesticide, as diuron, (N- (3,4-dichlorophenyl) -N,N-dimethylurea), in some crops in the world is common. Diuron can be biodegraded in three others compounds, 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 2,4-dichlorophenyl-N-methylurea (DCPMU). Normally, diuron have being applied associated with alkylphenols ethoxylates (APE), like nonilphenol (NP) and octylphenol (OP), which increase the solubility and dispersion of the herbicide. Some studies have shown that diuron and alkylphenols can cause enzymatic and/or estrogenic changes, in various organisms. Therefore, biotransformation enzymes, phase I (7-ethoxirresorufin-O-deethylase - EROD, 7- pentaxirisorufin-O-dealkylase - PROD, 7-benzyloxysorufin-O-desalkylase - BROD and P450 aromatase), phase II (glutathione-S-transferase-GST) and phase III proteins (multixenobiotic resistance - MXR), and antioxidant parameters (superoxide dismutase - SOD, catalase - CAT, glutathione peroxidase - GPx, glutathione reductase - GR, glutathione-6-phosphate dehydrogenase - G6PDH, aldehyde dehydrogenase - ALDH and lipid peroxidation), which are responsible for the control between production and degradation of reactive oxygen species (ROS). The endocrine parameters that can be altered and used as biomarkers are ... / Doutor

A adição de lodo de esgoto ao solo pode modificar o comportamento dos pesticidas. Sua degradação pode ser favorecida quando materiais orgânicos são adicionados ao solo, já que estes fornecem nutrientes e energia aos microrganismos capazes de degradar a molécula (Felsot & Dzantor, 1990). Por outro lado, solos ricos em matéria orgânica apresentam maior capacidade de retenção, diminuindo o potencial de lixiviação e a biodisponibilidade dos pesticidas às plantas e aos microrganismos. Nesse contexto, esta pesquisa objetivou avaliar o efeito do lodo de esgoto na biodegradação, sorção e dessorção do herbicida diuron em dois Latossolos. A biodegradação foi avaliada semanalmente, durante 63 dias, pelo método da radiorespirometria, sob condições controladas de umidade e temperatura. Ao final do período de incubação, a molécula original e os metabólitos formados foram extraídos e quantificados. Utilizou-se delineamento experimental inteiramente casualizado, em esquema fatorial 2(solos) x 3 (doses de lodo de esgoto: 0, 10 e 20 t ha-1). Paralelo ao ensaio de biodegradação, foram avaliadas a atividade e biomassa microbiana utilizando os mesmos tratamentos usados no ensaio de biodegradação, porém com dois fatores para o herbicida (com e sem herbicida). A atividade microbiana foi avaliada semanalmente e a biomassa foi avaliada no início e após 63 dias de incubação. Posteriormente, a sorção e adessorção foram avaliadas utilizando o método“Batch”, o herbicida foi aplicado, em cinco concentrações, na mistura solo + lodo sem incubação e após um período de incubação de 63 dias. Utilizou-se delineamento experimental inteiramente casualizado, em esquema fatorial 2(solos) x 3 (doses de lodo de esgoto: 0, 10 e 20 ton ha-1) x 2 (sem incubação e após 63 dias de incubação). Os resultados mostraram que a biodegradação e a dessorção foram diminuídas nos solos tratados com lodo de esgoto, enquanto a sorção e formação de resíduo ligado foram maiores nestes solos. A atividade e biomassa microbiana não foram afetadas pela adição do resíduo. Estes resultados evidenciam que a adição de lodo de esgoto ao solo pode reduzir a eficiência agronômica do diuron e aumentar sua persistência no ambiente, devido a maior retenção da molécula nos solos tratados com o resíduo. / Adding sludge to agricultural soil may modify the behavior of pesticides in the soil. In some cases, the application of organic amendment increases the degradation of pesticides, by providing nutrients and energy to the microorganisms able to degrade the molecule (Felsot & Dzantor, 1990), in other cases, the sorption is increased, resulting in the decrease of leaching potential of the molecule, and smaller bioavailability of the pesticide to the plants and to the microorganisms. In this context, the aim of this work was to evaluate the effect of the sewage sludge on the biodegradation of the diuron herbicide in 2 oxisoils. The biodegradation was evaluated weekly, for 63 days, by methods of the radiorespirometry, under controlled condition of the humidity and temperature. At the end of the incubation, the original compounds and their metabolites were extracted and quantify. Completely randomized design was used with a factorial experiment of 2 (soil ) x 3 (sewage sludge: 0, 10 e 20 ton ha-1). In parallel to this study, were evaluated the microbial activity and biomass, using the same treatments of the biodegradation experiment, but with two factories for herbicide (with and without herbicide).

The fate and behaviour of hydrophobic organic compounds (e.g. pesticides) in soils are largely controlled by sorption processes. Recent findings suggest that the chemical properties of soil organic carbon (OC) significantly control the extent of sorption of such compounds in soil systems. However, currently there is no practical tool to integrate the effects of OC chemistry into sorption predictions. Therefore, the K [subscript]oc model, which relies on the soil OC content (foc), is used for predicting soil sorption coefficients (K[subscript]d) of pesticides. The K[subscript]oc model can be expressed as K[subscript]d = K[subscript]oc × foc, where K[subscript]oc is the OC-normalized sorption coefficient for the compound. Hence, there is a need for a prediction tool that can effectively capture the role of both the chemical structural variation of OC as well as foc in the prediction approach. Infrared (IR) spectroscopy offers a potential alternative to the K[subscript]oc approach because IR spectra contain information on the amount and nature of both organic and mineral soil components. The potential of mid-infrared (MIR) spectroscopy for predicting K[subscript]d values of a moderately hydrophobic pesticide, diuron, was investigated. A calibration set of 101 surface soils from South Australia was characterized for reference sorption data (K[subscript]d and K[subscript]oc) and foc as well as IR spectra. Partial least squares (PLS) regression was employed to harness the apparent complexity of IR spectra by reducing the dimensionality of the data. The MIR-PLS model was developed and validated by dividing the initial data set into corresponding calibration and validation sets. The developed model showed promising performance in predicting K[subscript]d values for diuron and proved to be a more efficacious than the K[subscript]oc model. The significant statistical superiority of the MIR-PLS model over the K[subscript]oc model was caused by some calcareous soils which were outliers for the K[subscript]oc model. Apart from these samples, the performance of the two compared models was essentially similar. The existence of carbonate peaks in the MIR-PLS loadings of the MIR based model suggested that carbonate minerals may interfere or affect the sorption. This requires further investigation. Some other concurrent studies suggested excellent quality of prediction of soil properties by NIR spectroscopy when applied to homogenous samples. Next, therefore, the performance of visible near-infrared (VNIR) and MIR spectroscopy was thoroughly compared for predicting both foc and diuron K[subscript]d values in soils. Some eleven calcareous soils were added to the initial calibration set for an attempt to further investigate the effect of carbonate minerals on sorption. MIR spectroscopy was clearly a more accurate predictor of foc and K[subscript]d in soils than VNIR spectroscopy. Close inspection of spectra showed that MIR spectra contain more relevant and straightforward information regarding the chemistry of OC and minerals than VNIR and thus useful in modelling sorption and OC content. Moreover, MIR spectroscopy provided a better (though still not great) estimation of sorption in calcareous soils than either VNIR spectroscopy or the K[subscript]oc model. Separate research is recommended to fully explore the unusual sorption behaviour of diuron in calcareous soils. In the last experiment, two dimensional (2D) nuclear magnetic resonance/infrared heterospectral correlation analyses revealed that MIR spectra contain specific and clear signals related to most of the major NMR-derived carbon types whereas NIR spectra contain only a few broad and overlapped peaks weakly associated with aliphatic carbons. 2D heterospectral correlation analysis facilitated accurate band assignments in the MIR and NIR spectra to the NMR-derived carbon types in isolated SOM. In conclusion, the greatest advantage of the MIR-PLS model is the direct estimation of Kd based on integrated properties of organic and mineral components. In addition, MIR spectroscopy is being used increasingly in predicting various soil properties including foc, and therefore, its simultaneous use for K[subscript]d estimation is a resource-effective and attractive practice. Moreover, it has the advantage of being fast and inexpensive with a high repeatability, and unlike the K[subscript]oc approach, MIR-PLS shows a better potential for extrapolating applications in data-poor regions. Where available, MIR spectroscopy is highly recommended over NIR spectroscopy. 2D correlation spectroscopy showed promising potential for providing rich insight and clarification into the thorough study of soil IR spectra. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1415416 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2009

The fate and behaviour of hydrophobic organic compounds (e.g. pesticides) in soils are largely controlled by sorption processes. Recent findings suggest that the chemical properties of soil organic carbon (OC) significantly control the extent of sorption of such compounds in soil systems. However, currently there is no practical tool to integrate the effects of OC chemistry into sorption predictions. Therefore, the K [subscript]oc model, which relies on the soil OC content (foc), is used for predicting soil sorption coefficients (K[subscript]d) of pesticides. The K[subscript]oc model can be expressed as K[subscript]d = K[subscript]oc × foc, where K[subscript]oc is the OC-normalized sorption coefficient for the compound. Hence, there is a need for a prediction tool that can effectively capture the role of both the chemical structural variation of OC as well as foc in the prediction approach. Infrared (IR) spectroscopy offers a potential alternative to the K[subscript]oc approach because IR spectra contain information on the amount and nature of both organic and mineral soil components. The potential of mid-infrared (MIR) spectroscopy for predicting K[subscript]d values of a moderately hydrophobic pesticide, diuron, was investigated. A calibration set of 101 surface soils from South Australia was characterized for reference sorption data (K[subscript]d and K[subscript]oc) and foc as well as IR spectra. Partial least squares (PLS) regression was employed to harness the apparent complexity of IR spectra by reducing the dimensionality of the data. The MIR-PLS model was developed and validated by dividing the initial data set into corresponding calibration and validation sets. The developed model showed promising performance in predicting K[subscript]d values for diuron and proved to be a more efficacious than the K[subscript]oc model. The significant statistical superiority of the MIR-PLS model over the K[subscript]oc model was caused by some calcareous soils which were outliers for the K[subscript]oc model. Apart from these samples, the performance of the two compared models was essentially similar. The existence of carbonate peaks in the MIR-PLS loadings of the MIR based model suggested that carbonate minerals may interfere or affect the sorption. This requires further investigation. Some other concurrent studies suggested excellent quality of prediction of soil properties by NIR spectroscopy when applied to homogenous samples. Next, therefore, the performance of visible near-infrared (VNIR) and MIR spectroscopy was thoroughly compared for predicting both foc and diuron K[subscript]d values in soils. Some eleven calcareous soils were added to the initial calibration set for an attempt to further investigate the effect of carbonate minerals on sorption. MIR spectroscopy was clearly a more accurate predictor of foc and K[subscript]d in soils than VNIR spectroscopy. Close inspection of spectra showed that MIR spectra contain more relevant and straightforward information regarding the chemistry of OC and minerals than VNIR and thus useful in modelling sorption and OC content. Moreover, MIR spectroscopy provided a better (though still not great) estimation of sorption in calcareous soils than either VNIR spectroscopy or the K[subscript]oc model. Separate research is recommended to fully explore the unusual sorption behaviour of diuron in calcareous soils. In the last experiment, two dimensional (2D) nuclear magnetic resonance/infrared heterospectral correlation analyses revealed that MIR spectra contain specific and clear signals related to most of the major NMR-derived carbon types whereas NIR spectra contain only a few broad and overlapped peaks weakly associated with aliphatic carbons. 2D heterospectral correlation analysis facilitated accurate band assignments in the MIR and NIR spectra to the NMR-derived carbon types in isolated SOM. In conclusion, the greatest advantage of the MIR-PLS model is the direct estimation of Kd based on integrated properties of organic and mineral components. In addition, MIR spectroscopy is being used increasingly in predicting various soil properties including foc, and therefore, its simultaneous use for K[subscript]d estimation is a resource-effective and attractive practice. Moreover, it has the advantage of being fast and inexpensive with a high repeatability, and unlike the K[subscript]oc approach, MIR-PLS shows a better potential for extrapolating applications in data-poor regions. Where available, MIR spectroscopy is highly recommended over NIR spectroscopy. 2D correlation spectroscopy showed promising potential for providing rich insight and clarification into the thorough study of soil IR spectra. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1415416 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2009

Orientador: Eleni Gomes / Banca: Mirna Helena Regali Seleghim / Banca: Eduardo Alves de Almeida / Resumo: Os basidiomicetos são conhecidos por sua capacidade em degradar a madeira. Essa característica deve-se à sua habilidade em oxidar a lignina presente nas plantas. Essa molécula é um composto recalcitrante formado por sub-unidades de fenilpropanóides e as enzimas capazes de degradá-la são conhecidas conjuntamente como enzimas ligninolíticas. Tais enzimas são inespecíficas. Essa característica confere-lhes o seu emprego na oxidação de compostos que possuem estrutura molecular semelhante à da lignina, tais como pesticidas e hidrocarbonetos poli-aromáticos, que possuem anéis aromáticos em sua estrutura. Dessa forma, é possível utilizar tais enzimas na degradação desses xenobióticos. Alguns basidiomicetos possuem a habilidade de crescer em meio com baixa atividade de água. Assim, é possível usá-los em processos de biorremediação de ambientes que possuem uma alta concentração de solutos, como em meios com alta salinidade. Esse trabalho teve como objetivo o estudo da capacidade de crescimento em meio líquido agitado com baixa atividade de água do basidiomiceto Dacryopinax elegans SXS323, promovida pela adição de cloreto de sódio 0,5 M, manitol 0,5 M ou glicerol 0,5 M ao meio de cultura; a produção de enzimas ligninolíticas e o seu poder de degradação do herbicida diurom nessas condições. Verificou-se que o basidiomiceto foi capaz de crescer sob todos os meios testados, sendo este mais pronunciado quando manitol ou glicerol foram acrescentados ao meio, averiguando-se um estímulo de crescimento. O manitol e o glicerol serviram como fonte secundária de carbono. O cloreto de sódio inibiu seu crescimento. Outro fator de inibição do crescimento foi a adição de diurom. A produção de enzimas ligninolíticas foi muito baixa, com pico de atividade de 3,67 U . L -1 com 144 horas de cultivo em meio com glicerol 0,5M. Apesar disso, detectou-se degradação... (Resumo comp'leto, clicar acesso eletrônico abaixo) / Abstract: The basidiomycetes are known for their ability to degrade wood. This feature is due to its ability to oxidize lignin of plants. This molecule is a compound formed by recalcitrant sub-units of phenylpropanoids and enzymes able to degrade it and are known as ligninolytic enzymes. These enzymes are nonspecific. This characteristic provides them the capability of oxidation of compounds that have molecular structures similar to lignin, such as pesticides and polyaromatic hydrocarbons, which possess aromatic rings in their structure. Thus, it is possible to use such enzymes in the degradation of xenobiotics. Some basidiomycetes have their ability to grow in media with low water activity. Thus, it can be used in bioremediation process in environments that have a high concentration of solutes, such as hypersaline environments. This work aimed to study the capability of the basidiomycete Dacryopinax elegans SXS323 to grow in liquid shaken with low water activity, promoted by the addition of sodium chloride 0.5 M, mannitol 0.5 M or glycerol 0.5 M to the medium culture, the production of ligninolytic enzymes and their degradation capability of the herbicide diuron in these conditions. It was found that the basidiomycete was able to grow in all media tested. The growth was most pronounced when mannitol or glycerol was added to the medium, probably working as a stimulus for growth, and were used as a secondary source of carbon. Sodium chloride inhibited its growth. Another factor inhibiting the growth was the addition of diuron. The ligninolytic enzyme production was very low, with peak activity of 3.67 U. L -1 with 144 hours in medium with glycerol 0.5 M. Nevertheless, we detected the degradation of the herbicide, registering 32.63% (glycerol 0.5 M, 192 hours), 25.47% (mannitol 0.5 M, 192 hours) 20.51% of reduction in medium with glucose 5.0 g . L -1 (240 hours)... (Complete abstract click electronic access below) / Mestre

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-10-29T23:59:53Z No. of bitstreams: 1 Gessica_Wernke_2016.pdf: 922626 bytes, checksum: 30a185f73d96f9bfc6546fd05ef03857 (MD5) / Made available in DSpace on 2018-10-29T23:59:54Z (GMT). No. of bitstreams: 1 Gessica_Wernke_2016.pdf: 922626 bytes, checksum: 30a185f73d96f9bfc6546fd05ef03857 (MD5) Previous issue date: 2016-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aims to evaluate the efficiency of Moringa oleifera as bark biosorbent to remove Diuron® herbicide, batch and fixed bed column. The characterization of biosorbent was performed by spectroscopy method infrared Fourier transform (FTIR), scanning electron microscopy (MEV) and textural properties by the BET method before and after biosorption process in fixed bed column. For batch systems the evaluated experimental conditions were biosorbent mass, particle size, pH, temperature and stirring speed. From studies in batch experimental conditions were determined for study in a fixed bed column, such experimental conditions were the amount of mass of the biosorbent (0,750, 1,5 and 3 g), concentration of the adsorvate (5; 10; 17 , 20 and 33 mg L- 1), feed flow (1, 2 and 3 ml min-1) and pH (4, 7 and 10). The results biosorption in a fixed bed column had a higher percentage removal in low- flow operating conditions (47,44 %) , larger bed height (50,55%), 5 mg L- 1 (47,07 %) and pH 7 (55,10 %). In the evaluation of the biosorbent regeneration capacity were used the best experimental conditions obtained in the study in a fixed bed column, which was used as solvent ultra-pure water. With study analysis biosorption/desorption was observed that there was a complete regeneration of the biosorbent after six cycles. To describe the experimental data of breakthrough curves obtained in a fixed bed column, the mathematical models available in the literature were used. The most satisfactory model that represented the initial process of experimental data was the internal resistance can be regarded as limiting mass transfer step the biosorption process Diuron® herbicide. / Este trabalho visa avaliar a eficiência da casca da Moringa oleifera como biossorvente para remoção do herbicida Diuron®, em batelada e em coluna de leito fixo. A caracterização do biossorvente foi realizada pelo método de espectroscopia no infravermelho com transformada de Fourier (FTIR), microscopia eletrônica de varredura (MEV) e as propriedades texturais pelo método BET antes e após o processo de biossorção em coluna de leito fixo. Para o sistema em batelada as condições experimentais avaliadas foram de massa de biossorvente, granulometria, pH, temperatura e velocidade de agitação. A partir dos estudos em batelada foram determinadas as condições experimentais para o estudo em coluna de leito fixo, tais condições experimentais foram a quantidade de massa do biossorvente (0,750, 1,5 e 3 g), concentração do adsorvato (5; 10; 17; 20 e 33 mg L-1), vazões de alimentação (1, 2 e 3 mL min-1) e pH (4, 7 e 10). Os resultados de biossorção em coluna de leito fixo apresentaram uma maior porcentagem de remoção nas condições operacionais de menor vazão (47,44%), maior altura de leito (50,55%), concentração de 5 mg L-1 (47,07%) e pH 7 (55,10%). Na avaliação da capacidade de regeneração do biossorvente foram utilizadas as melhores condições experimentais obtidas no estudo em coluna de leito fixo, na qual foi utilizada como solvente a água ultra-pura. Com a análise do estudo de biossorção/dessorção, observou-se que houve uma completa regeneração do biossorvente após seis ciclos. Para descrever os dados experimentais das curvas de ruptura obtidos em coluna de leito fixo, foram utilizados os modelos matemáticos disponíveis na literatura. O modelo mais satisfatório que representou o processo inicial dos dados experimentais foi a resistência interna, podendo ser considerado como a etapa de transferência de massa limitante ao processo de biossorção do herbicida Diuron®.

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