Submitted by Fabíola Cristina Ricci Spazzini (fabi08ricci@gmail.com) on 2018-10-10T15:16:55Z No. of bitstreams: 1 Dissertação Mestrado_Fabíola_Versão final.pdf: 1879729 bytes, checksum: d293838704cda510bd445097e219b488 (MD5) / Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-10-10T16:44:06Z (GMT) No. of bitstreams: 1 spazzini_fcr_me_bauru.pdf: 1879729 bytes, checksum: d293838704cda510bd445097e219b488 (MD5) / Made available in DSpace on 2018-10-10T16:44:06Z (GMT). No. of bitstreams: 1 spazzini_fcr_me_bauru.pdf: 1879729 bytes, checksum: d293838704cda510bd445097e219b488 (MD5) Previous issue date: 2018-08-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A contaminação ambiental por efluentes orgânicos é atualmente um dos problemas ambientais mais sérios e, por conta disso, a eliminação desses poluentes tem sido largamente estudada. A degradação fotocatalítica mediada por dióxido de titânio (TiO2) de poluentes orgânicos, corantes e medicamentos é um assunto atual e intensamente investigado em ciências materiais e ambientais. Este processo é baseado em espécies reativas de oxigênio (EROs) geradas pela transferência de elétrons fotoinduzidos, provocando a oxidação da água e a redução do oxigênio dissolvido, levando à formação de radical hidroxila (HO●) e ânion superóxido (O2●-). Este trabalho teve como objetivo estudar a importância da susceptibilidade à oxidabilidade e ao ataque eletrofílico de compostos orgânicos em fármacos submetidos à degradação por fotocatálise mediada por TiO2. Para esse trabalho, a rodamina B foi utilizada como composto modelo para avaliar o efeito das EROs e moléculas orgânicas como o ácido salicílico, ácido benzóico, ácido protocatecúico, anisol, acetofenona e nitrobenzeno foram utilizados para avaliar a importância da susceptibilidade ao ataque eletrofílico e à oxidação. O TiO2 foi utilizado como catalisador em um meio constituído pelo analito pré-determinado, sob irradiação por luz ultravioleta (UVC, 6W). A reação foi monitorizada por 2,5 horas e as amostras foram removidas a intervalos de 30 minutos. A importância de cada EROs foi avaliada por desaeração do meio, adição de catalase, dimetilsulfóxido (DMSO), etanol e iodeto de potássio (KI), que foram utilizados para remoção de oxigênio dissolvido, peróxido de hidrogênio (H2O2), HO● e buracos na banda de valência, respectivamente. Verificou-se que o processo fotocatalítico não foi afetado pela desaeração, o que indicou que o O2 não foi relevante para a degradação da rodamina B. Resultados similares foram obtidos utilizando catalase, uma enzima capaz de degradar H2O2. A adição de KI provocou efeito inibitório significativo revelando a importância da formação dos buracos na banda de valência do semicondutor. O etanol demostrou-se como um inibidor potente, o que evidencia que os HO● foram a EROs mais relevante nesse estudo, enquanto que O2●-e H2O2 apresentaram-se menos efetivos perante as reações de fotodegradação. Em relação à classe de compostos analisados, verificou-se que a oxidabilidade dos compostos foi pouco relevante, pois todos foram eficientemente degradados. Com relação a susceptibilidade a ataque eletrofílico, verificou-se uma maior reatividade, embora sutil, à fotodegradação dos compostos mais reativos sob este aspecto. Não foi possível estabelecer um padrão de estrutura e reatividade para os fármacos estudados, pois o cetoprofeno foi susceptível a degradação mesmo na ausência de TiO2 e o paracetamol mostrou-se pouco reativo. Em conclusão, este texto apresenta um conjunto de resultados que podem ser úteis para pesquisadores que estudam processos de fotodegradação de compostos orgânicos. / Environmental contamination by organic effluents is currently one of the most serious environmental problems and, as a result, the elimination of these pollutants has been widely studied. Photocatalytic degradation mediated by titanium dioxide (TiO2) from organic pollutants, dyes and drugs is a current and intensely investigated subject in the environmental and material sciences. This process is based on reactive oxygen species (ROS) generated by photoinduced electron transfer, causing the oxidation of water and the reduction of dissolved oxygen, leading to the formation of hydroxyl radical (HO●) and superoxide anion (O2 ●- ). This work aimed to study the importance of the susceptibility to oxidation and electrophilic attack of organic compounds in drugs submitted to degradation by TiO2 mediated photocatalysis. For this work, rhodamine B was used as a model compound to evaluate the effect of EROs and organic molecules such as salicylic acid, benzoic acid, protocatechuic acid, anisole, acetophenone and nitrobenzene were used to evaluate the importance of susceptibility to electrophilic attack and oxidation. TiO2 was used as a catalyst in a medium consisting of the predetermined analyte, under ultraviolet light irradiation (UVC, 6W). The reaction was monitored for 2.5 hours and the samples were removed at 30 minute intervals. The importance of each ERO was evaluated by deaeration of the medium, addition of catalase, dimethylsulfoxide (DMSO), ethanol and potassium iodide (KI), which were used to remove dissolved oxygen, hydrogen peroxide (H2O2), HO● and holes in the valence band, respectively. It was found that the photocatalytic process was not affected by the deaeration, which indicated that O2 was not relevant for the degradation of rhodamine B. Similar results were obtained using catalase, an enzyme capable of degrading H2O2. The addition of KI caused a significant inhibitory effect revealing the importance of the formation of the holes in the semiconductor valence band. Ethanol was shown to be a potent inhibitor, which evidenced HOs where EROs were more important in this study, while their effects were more important than photodegradation reactions. In relation to the class of compounds analyzed, it was verified that the oxidability of the compounds was little relevant, since all were efficiently degraded. Regarding the susceptibility to electrophilic attack, a greater reactivity, although subtle, was verified to the photodegradation of the most reactive compounds in this aspect. It was not possible to establish a pattern of structure and reactivity for the drugs studied, since ketoprofen was susceptible to degradation even in the absence of TiO2 and paracetamol showed little reactivity. In conclusion, this text presents a set of results that may be useful for researchers studying processes of photodegradation of organic compounds. / CNPq: 134799/2016-0

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Submitted by Bruna Rodrigues (bruna92rodrigues@yahoo.com.br) on 2016-09-27T11:47:25Z No. of bitstreams: 1 DissMD.pdf: 3874080 bytes, checksum: f245af64331a5190649cede80208ac01 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T18:10:35Z (GMT) No. of bitstreams: 1 DissMD.pdf: 3874080 bytes, checksum: f245af64331a5190649cede80208ac01 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T18:10:41Z (GMT) No. of bitstreams: 1 DissMD.pdf: 3874080 bytes, checksum: f245af64331a5190649cede80208ac01 (MD5) / Made available in DSpace on 2016-10-04T18:10:51Z (GMT). No. of bitstreams: 1 DissMD.pdf: 3874080 bytes, checksum: f245af64331a5190649cede80208ac01 (MD5) Previous issue date: 2015-03-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / This dissertation studies the application of rutile substrate as an alternative support for anatase films, specifically, on the growth and properties of anatase films. The films were utilized as catalysts for the photodegradation of water contaminants (Atrazine and Rhodamine B). Ti4+ precursor resin was prepared by the polymeric precursor method and deposited by spin coating onto polycrystalline rutile and rutile coated glass substrates. The films were calcined at different temperatures (350 °C to 500 °C) to form anatase TiO2 films. The influence of temperature on the properties of the films has been reported in this study. A comparative study of the films was also done using X-ray diffraction technique (XRD), grazing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). XRD and GIXRD results confirmed the formation of anatase on the (101) plane depending on the calcination temperature. Bandgap modification of the films with respect to calcination temperature was measured by UV visible diffuse reflectance spectroscopy. The bandgaps were in the range of 2.74 to 2.85 eV. Photocatalytic activity of the films supported on rutile substrate was studied for the degradation of Atrazine (ATZ) and Rhodamine B (Rhod-B) under UV light. Further, the stability of the films was evaluated on four consecutive cycles where the films maintained their photocatalytic properties in all cases. The kinetics of Rhod-B and ATZ degradation followed a pseudo first order and first order exponential decay respectively. The films calcined at 450 °C and 500 °C showed superior photocatalytic activity for Rhod-B degradation than the films calcined at 350 °C and 400 °C. This is attributed to the adequate crystallinity of anatase. For ATZ degradation, the films were also efficient but no specific trend was observed. The results can contribute towards the development of TiO2 films on rutile phase substrates. / Esta dissertação estuda a aplicação de substratos de rutilo como suportes alternativos para filmes de anatase, especificamente, sobre o crescimento e propriedades de filmes de anatase sobre rutilo. Os filmes foram utilizados como catalisadores para a fotodegradação de contaminantes de água (Atrazina e Rodamina B). A resina de Ti4+ foi preparada pelo método de precursores poliméricos e depositada por spin coating sobre rutilo policristalino e em substratos de vidro revestido de rutilo. As amostras foram calcinadas a diferentes temperaturas (350 a 500 °C) para formar filmes de anatase TiO2. Um estudo comparativo dos filmes foi feito usando a técnica de difração de raios X (DRX), difração de raios X com ângulo rasante (DRXR), microscopia de força atômica (AFM) e microscopia eletrônica de varredura (MEV). Os resultados de DRX e DRXR confirmaram a formação de anatase nos filmes ao longo do plano (101) dependendo da temperatura de calcinação. Modificações do bandgap dos filmes de acordo com a temperatura de calcinação foram medidas por reflectância difusa de UV-visível onde os bandgaps variou de 2,74 para 2,85 eV. Atividade fotocatalítica dos filmes imobilizados sobre substrato de rutilo foi estudada para a degradação de Atrazina (ATZ) e Rodamina B (Rhod-B) sob luz UV. Além disso, a estabilidade dos filmes foi avaliada em quatro ciclos consecutivos onde os filmes mantiveram suas propriedades fotocatalíticas em todos os ciclos. As cinéticas de degradação de Rhod-B e de ATZ seguiram um ajuste de pseudo-primeira ordem e decaimento exponencial de primeira ordem, respectivamente. Os filmes que foram calcinados a 450 °C e 500 °C mostraram atividade fotocatalítica superior para a degradação de Rhod-B aos filmes calcinados a 350 °C e 400 °C. Isto foi atribuído à cristalinidade adequada da fase anatase. Para ATZ, os filmes foram eficientes mas nenhuma tendência especifica foi observada. Os resultados podem contribuir para o desenvolvimento de filmes de TiO2 imobilizados sobre substratos de rutilo.

abstract: The mitigation and conversion of carbon dioxide (CO2) to more useful carbon chemicals is a research topic that is at the forefront of current engineering and sustainability applications. Direct photocatalytic reduction of CO2 with water (H2O) vapor to C1-C4 hydrocarbons has significant potential in setting substantial groundwork for meeting the increasing energy demands with minimal environmental impact. Previous studies indicate that titanium dioxide (TiO2) containing materials serve as the best photocatalyst for CO2 and H2O conversion to higher-value products. An understanding of the CO2-H2O reaction mechanism over TiO2 materials allows one to increase the yield of certain products such as carbon monoxide (CO) and methane (CH4). The basis of the work discussed in this thesis, investigates the interaction of small molecules (CO, CH4,H2O) over the least studied TiO2 polymorph - brookite. Using the Gaussian03 computational chemistry software package, density functional theory (DFT) calculations were performed to investigate the adsorption behavior of CO, H2O, and CH4 gases on perfect and oxygen-deficient brookite TiO2 (210) and anatase TiO2 (101) surfaces. The most geometrically and energetically favorable configurations of these molecules on the TiO2 surfaces were computed using the B3LYP/6-31+G(2df,p) functional/basis set. Calculations from this theoretical study indicate all three molecules adsorb more favorably onto the brookite TiO2 (210) surface. Diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) was used to investigate the adsorption and desorption behavior of H2O and CH4 on Evonik P25 TiO2. Results from the experimental studies and theoretical work will serve as a significant basis for reaction prediction on brookite TiO2 surfaces. / Dissertation/Thesis / M.S. Chemical Engineering 2012

L'objectif de la thèse est de mieux comprendre les mécanismes de dégradation photocatalytique se produisant sous air ou sous azote en étudiant la disparition, la minéralisation et les produits intermédiaires d'une molécule simple l'acide acétique. Les réactions sont réalisées sous ces deux atmosphères afin de se placer dans des conditions de dépollution ou de génération d'énergie. L'étude est réalisée en phase gazeuse et sous flux en prenant comme molécule organique une molécule simple l'acide acétique. Dans un premier temps nous avons étudié la dégradation de l'acide acétique en utilisant le photocatalyseur de référence, TiO2 P25. Quel que soit le flux gazeux de réaction, air ou N2, nous avons montré que la réaction de décarboxylation est la première étape de la disparition de l'acide acétique. Cependant, le sort du groupe méthyle dépend du gaz porteur et du débit molaire (en d'autres termes de la concentration du polluant en phase gazeuse). Le mécanisme de dégradation se produisant à la surface du photocatalyseur est alors représenté pour expliquer l'importance de ce mécanisme comparé à celui faisant intervenir les radicaux hydroxyles. La schématisation du mécanisme inclut la régénération du photocatalyseur et la formation possible de H2O2, lequel a été observé dans la littérature. Il est également noté que la sélectivité d'éthane observé sous flux d'air augmente avec la concentration en polluant et correspond à la réaction de deux radicaux méthyl. Comme précédemment la formation de ce composé en surface du TiO2 est proposée. L'étude des produits de dégradation de l'acide acétique marqué par du carbone 13 sur le groupe carbonyle (CH313COOH) suggère que l'acétone et l'acétaldéhyde ne proviennent pas de la réduction du groupe carboxylique. Dans une seconde étape l'impact du flux photonique et de l'humidité en présence de TiO2 P25 et l'effet de différents TiO2 commerciaux sur la conversion et plus particulièrement la distribution des produits intermédiaires ont été étudiés. La comparaison de l'efficacité de différents TiO2 commerciaux a été discutée en considérant la présence de phase rutile, la nature des espèces actives, la surface spécifique de TiO2, le nombre de groupes OH à la surface des catalyseurs, la présence d'impuretés et la porosité des matériaux. Notre étude s'est ensuite focalisée sur la détermination de l'efficacité d'échantillons de TiO2 modifiés par ajout d'or afin d'améliorer la séparation des charges et ainsi la dégradation de polluant en présence d'air ou la formation de produit en présence de flux d'azote. Deux séries de Au/TiO2 avec les mêmes charges d'or (~ 0,16% en poids) ont été préparées par les deux méthodes: pyrolyse laser et pyrolyse par pulvérisation de flamme (Au-TiO2 LP et Au-TiO2 FSP). Les résultats ont montré que la présence d'or améliore l'activité photocatalytique dans l'air dans le cas des échantillons préparés par pyrolyse laser alors qu'aucun effet n'est observé avec les catalyseurs préparés par pyrolyse à flamme (FSP). Ce résultat s'explique en considérant la taille des nanoparticules d'or plus petite dans le cas des échantillons obtenus par pyrolyse laser. L'effet inverse est observé sous atmosphère de N2, la présence d'or diminue de plus de moitié la dégradation de l'acide acétique mais favorise la formation d'éthane. Ce résultat est discuté en considérant la présence d'or sous forme cationique. Malheureusement, par XPS, il n'a pas été possible d'observer d'or probablement dû à sa faible quantité. L'impact du dopage à l'azote de TiO2 LP et Au-TiO2 LP a également été étudié. Ce dopage diminue l'efficacité de cet échantillon. Finalement des études préliminaires ont été conduite d'une part sur l'efficacité de textile lumineux photocatalytique pour dégrader l'acide acétique afin d'améliorer les rendements quantiques et d'autre part sur les efficacités de catalyseurs Ag/TiO2 lesquels, outre diminué la pollution organique permettrait également l'inactivation des microorganismes / The objective of the thesis is to better understand the mechanisms of photocatalytic degradation occurring under air or under nitrogen by studying the disappearance, mineralization and intermediate products of a simple molecule acetic acid. The reactions are carried out under these two atmospheres in gas phase and dynamic mode in order to place themselves under conditions of depollution or of energy generation. Firstly, we studied the degradation of acetic acid using the reference photocatalyst, TiO2 P25. Regardless of the atmosphere, air or N2, we have shown that the decarboxylation reaction is the first step in the disappearance of acetic acid. However, the fate of the methyl group depends on the carrier gas and the molar flow rate (in other words, the concentration of the pollutant in the gas phase). The mechanism of degradation occurring on the surface of the photocatalyst is then represented to explain the importance of this mechanism compared to that involving the hydroxyl radicals. The schematization of the mechanism includes the regeneration of the photocatalyst and the possible formation of H2O2, which has been observed in the literature. The study of the degradation products of acetic acid labelled with carbon 13 on the carbonyl group (CH313COOH) suggests that acetone and acetaldehyde do not result from the reduction of the carboxylic group. In a second step, the impact of photonic flux and moisture in the presence of TiO2 P25 as well as the effect of different commercial TiO2 on the conversion and more particularly the distribution of the intermediate products have been studied. Comparison of the effectiveness of different commercial TiO2s was discussed by considering the presence of rutile phase, the nature of the active species, the specific surface area of TiO2, the number of OH groups on the surface of the catalysts, the presence of impurities and the porosity of the materials

L'objectif de ce travail est de mettre au point des catalyseurs bimétalliques Re-Pd/TiO2 actifs et suffisamment robustes en milieu hydrothermal pour hydrogéner sélectivement l'acide succinique (SUC) en 1,4-butanediol (BDO). Dans un premier temps, des catalyseurs monométalliques 2%Pd/TiO2 sont préparés et caractérisés par diverses techniques physico-chimiques. Les résultats montrent l'importance d'un certain nombre de paramètres sur les propriétés des catalyseurs et leurs performances catalytiques. Les catalyseurs à base de palladium sont très sélectifs en γ-butyrolactone mais très peu en BDO. Différentes teneurs en rhénium sont ensuite déposées sur les catalyseurs 2%Pd/TiO2 (par imprégnation successive (IS) et par réduction catalytique (RC)). L'existence d'une interaction entre les deux métaux Pd-Re est mise en évidence par plusieurs techniques de caractérisation (chimisorption H2, réaction modèle de déshydrogénation du cyclohexane, RTP, XPS, MET-EDX). L'ajout de rhénium permet d'augmenter la vitesse de la réaction de transformation du SUC et améliore la sélectivité en BDO. Pour les catalyseurs préparés par IS, des quantités importantes de rhénium (3-4%) sont nécessaires pour avoir un effet optimum, alors que le dépôt par la méthode RC doit être limité à des teneurs plus faibles (< 1%). Néanmoins, les catalyseurs préparés par IS conduisent à une meilleure activité et sélectivité en BDO. / The objective of this work is to synthesize bimetallic catalysts Re-Pd/TiO2 active and strong enough in hydrothermal environment to hydrogenate selectively the succinic acid (SUC) to 1,4-butanediol (BDO). At first, monometallic 2%Pd/TiO2 catalysts are prepared and characterized by various physico-chemical methods. The results show the importance of several parameters on the catalyst properties and catalytic performances. Palladium catalysts are very selective to γ-butyrolactone but few to BDO. Various rhenium contents are then deposited on 2%Pd/TiO2 catalysts (by successive impregnation (SI) and catalytic reduction (CR)). The existence of an interaction between both Pd-Re metals is revealed using several techniques of characterization (H2 chemisorption, model reaction of cyclohexane dehydrogenation, TPR, XPS, TEM-EDX). Adding rhenium both allows enhancing the reaction rate of SUC transformation and improving the selectivity to BDO. For catalysts prepared by SI, important quantities of rhenium (3-4%) are needed for optimal effect, while the deposit must be limited to lower contents (< 1%) when using the CR method. Nevertheless, catalysts prepared by SI lead to better activity and selectivity to BDO.

Les nanoparticules ont soit une origine naturelle soit une origine anthropique. De par l’évolution technologique, l’homme produit des quantités croissantes de nanoparticules susceptibles de se retrouver dans l’environnement. Afin de prévenir les risques inhérents à ces rejets, pour la santé humaine ou l’environnement, il est nécessaire de caractériser au mieux les effets potentiels des nanoparticules et d’identifier les mécanismes qui régissent leurs interactions avec les organismes exposés. Dans ce contexte, le premier objectif de ces travaux était de mettre en évidence les mécanismes gouvernant les interactions entre bactéries et nanoparticules et de documenter l'influence de ces interactions sur la toxicité et génotoxicité des NPs pour les bactéries. Le second objectif était de déterminer en quoi cette toxicité et cette génotoxicité pouvait impacter les organismes bactériens au niveau communautaire. Les résultats ont montré que les interactions électrostatiques attractives entre les bactéries et les TiO2-NPs conditionnaient l’adsorption des nanoparticules à la surface des bactéries et conduisaient à la détection d’une toxicité modulées par les électrolytes présents dans la solution. De plus, les déterminants biophysiques de l’interphase bactérienne, et particulièrement la longueur des LPS et le type de protéines affleurant à la surface de la membrane externe, sont des paramètres de premier ordre dans l'apparition d'un potentiel néfaste pour les microorganismes. En prenant en compte ces interactions, nous avons mis en évidence le potentiel mutagène des TiO2-NPs. Un effet toxique et génotoxique ayant été constaté, les communautés bactériennes ont ensuite été étudiées. Il a été mis en évidence que les TiO2-NPs modifiaient la composition, la structure et la prévalence des communautés bactériennes libres et fixées sous forme de biofilms précoces d’une communauté aquatique naturelle d’eau douce. Ces travaux mettent en évidence l’impact potentiel des TiO2-NPs sur les organismes bactériens dans un contexte d’évaluation des risques et indiquent que les nanoparticules pourraient impacter les communautés microbiennes et pourraient présenter un risque pour le bon fonctionnement de l’écosystème / Nanoparticles have either natural or anthropogenic origin. By technological change, man produces increasing amounts of nanoparticles likely to end in the environment. To prevent inherent risks to human health or environment from these releases, it is necessary to characterize the best potential effects of nanoparticles and to identify the mechanisms governing their interactions with exposed organisms. In this context, the first objective of this work was to highlight the mechanisms governing interactions between nanoparticles and bacteria and document the influence of these interactions on toxicity and genotoxicity of NPs for bacteria. The second objective was to determine how this toxicity and genotoxicity could impact bacteria at community level. Results showed that electrostatic attractive interaction between bacteria and TiO2-NPs conditioned adsorption of nanoparticles on bacterial surfaces and led to the detection of toxicity modulated by electrolytes in solution. In addition, the biophysical determinants of bacterial interphase, particularly the length of LPS and protein type flush with the outer membrane surface, are key parameters in adverse potential of NPs for microorganisms. Taking into account these interactions, we highlighted the mutagenic potential of TiO2-NPs. Toxic and genotoxic effect was found, leading to study the effects on bacterial communities. It has been demonstrated that TiO2-NPs altered the composition, structure and prevalence of planktonic and sessile communities of an aquatic natural freshwater. These studies highlight the potential impact of TiO2-NPs on bacteria in a risk assessment context and suggest that nanoparticles may impact microbial communities and could present a risk to the ecosystem functioning

L’analyse du cycle de vie et l’évaluation du risque ont été combinées afin d’évaluer les impacts et risques potentiels de NMs de TiO2 dans l’eau, les sols et les sédiments à une échelle site-spécifique. Une approche analytique a permis de caractériser les NMs industriels dans les eaux, sols et sédiments et de déterminer leur comportement dans l’eau. Un modèle bayésien a été réalisé pour évaluer leur devenir dans les eaux et sédiments de la rivière, ainsi que leurs effets et risques associés en mésocosmes. Il a ainsi été montré que le TiO2 est présent en faible concentration dans l’eau de rivière. En mésocosmes, des risques ont été quantifiés sur deux espèces : Dreissena polymorpha et Gammarus roeseli. Il est apparu nécessaire de mieux caractériser la dimension fractale des agrégats de NMs pour comprendre leur sédimentation et de quantifier les effets des nano-TiO2 dans le milieu naturel, en dépassant l’approche par mésocosmes. / In this work, life cycle and risk assessments were combined in order to assess the potential impacts and risks of TiO2 NMs in water, soils and sediments at a site-specific scale. Two approaches were used: (1) An analytical approach allowed the analysis of waters, sediments and soils, the characterization of industrial NMs and the determination of their aggregation behavior in water; (2) A Bayesian modeling approach was used to assess their fate in the river water and sediments, as well as their potential effects and risks in mesocosms. It was thus shown that TiO2 occurs at low concentrations in the river water. Quantifying the TiO2 mass which deposits on the sediment requires characterizing more precisely their fractal dimension. Finally, nano-TiO2 were shown to induce risks to two species in mesocosms: it is consequently necessary to assess the potential effects of the nano-TiO2 produced on the study area in mesocosms, simulating realistic conditions.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20234号 / 医博第4193号 / 新制||医||1019(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 安達 泰治, 教授 横出 正之, 教授 鈴木 茂彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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