As two of the most abundant natural polymers, chitin and lignin not only play critical roles in fungal and plant cell walls but are also important functional materials and promising feedstocks for a variety of chemicals. This study investigated the interactions of chitin and lignin thin films with several other molecules via a quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). Interactions between chitin and family 18 chitinases are vital for understanding bacterial invasion of fungi and human defense against fungal infection. Regenerated chitin (RChitin) thin films were prepared via chemical conversion and spin-coating. Changes in their mass and viscoelasticity were monitored by a QCM-D in real time during incubation with family 18 chitinases. The optimal temperature for the activity of chitinases on surfaces was lower than bulk solution studies in the literature. Family 18 chitinases showed greater activity on dissolved chitin oligosaccharides while family 19 chitinases showed greater activity on RChitin films, which was attributed to chitin-binding domains in family 19 chitinases. Catechyl lignin (C-lignin) is a promising substrate for lignin valorization. Films of C-lignin were synthesized via adsorbed horseradish peroxidase-catalyzed dehydrogenative polymerization (DHP) of caffeyl alcohol (C-alcohol), and degraded through Fenton chemistry with all processes observed by a QCM-D and AFM. The synthetic rate and yield for C-DHP films was lower than DHP films made from coniferyl alcohol (G-alcohol) and p-coumaryl alcohol (H-alcohol). The C-DHP film underwent complete Fenton mediated degradation in contrast to the G-DHP and H-DHP films regardless of their thicknesses. Conventional lignin suffers from recalcitrance to degradation. Copolymer lignin films were synthesized through surface-initiated copolymerization of C and G or C, G and H monolignols. As the concentration of C-alcohol increased, the percentage degradation of the synthesized DHP copolymer films increased. Almost all the CG-DHP or CGH-DHP films were degraded when the percentage of the C-alcohol in the polymerization feed was ≥ 75% and ≥ 60% for CG-DHP and CGH-DHP, respectively. / Doctor of Philosophy / Natural polymers are widely considered as an alternative to fossil fuels for the production of biofuels, biochemicals, and biomaterials. The features of their biodegradability, biocompatibility, and sustainability can significantly alleviate concerns about environmental pollution and energy security. The surfaces of natural polymers are critical to their properties and applications. This dissertation focuses on the study of interfacial behaviors occurring at two of the most abundant natural polymers, chitin and lignin, via surface analysis techniques, a quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). When an endosymbiont bacteria enter a fungal host, they secrete chitinases to soften and loosen the chitin layer in the fungal cell wall. Small chitin fragments will be released from digestion of the chitin layer of the fungal cell wall by chitinases in humans suffering from fungal infections. In order to fully understand the interactions between the fungal chitin layer and chitinases, a chitin thin film was fabricated to mimic the chitin layer, and the changes of the chitin film in mass, viscoelasticity, and morphology during treatment with family 18 chitinases were studied at various temperatures and pH using a QCM-D and AFM. Family 19 chitinases produced greater degradation of chitin thin films than family 18 chitinases, even though the family 18 chitinases had greater activity in solution. Greater surface activity for family 19 chitinases were attributed to chitin-binding domains in their chemical structure that are absent in family 18 chitinases. Millions of tons of lignin are produced in the lignocellulosic biorefinery and are discarded every year due to their recalcitrance to degradation as a result of their heterogeneous and complex structure. A newly discovered lignin, catechyl lignin (C-lignin), has potential for enhancing degradation on account of its simple linear structure. In this dissertation, C-lignin thin films were synthesized on gold-coated QCM-D sensor surfaces via surface-initiated dehydrogenative polymerization of caffeyl alcohol (C-alcohol). Their enzymatic and chemical degradation was investigated. It was found that the C-lignin films underwent complete chelator-mediated Fenton degradation in contrast to conventional lignin films. Although the C-lignin promises to be an ideal substrate for lignin valorization, its narrow distribution in nature severely limits its wide application. In view of this limitation, some people are trying to incorporate C units into conventional lignin through genetically engineered plants. This dissertation demonstrates the successful copolymerization of C-alcohol with conventional monolignols and the improved degradation of the synthesized C unit-containing copolymer lignin films relative to conventional lignin films. The results are expected to inform the design of lignocellulosic biomass for greater utilization.

No / Vitiligo is characterized by a mostly progressive loss of the inherited skin color. The cause of the disease is still unknown, despite accumulating in vivo and in vitro evidence of massive oxidative stress via hydrogen peroxide (H2O2) and peroxynitrite (ONOO−) in the skin of affected individuals. The most favored hypothesis is based on autoimmune mechanisms. Since depletion of the essential amino acid l-tryptophan (Trp) severely affects various immune responses, we here looked at Trp metabolism and signaling in these patients. Our in vivo and in vitro data revealed total absence of epidermal Trp hydroxylase activities and the presence of H2O2/ONOO− deactivated indoleamine 2,3-dioxygenase. Aryl hydrocarbon receptor signaling is severely impaired despite the ligand (Trp dimer) being formed, as shown by mass spectrometry. Loss of this signal is supported by the absence of downstream signals (COX-2 and CYP1A1) as well as regulatory T-lymphocytes and by computer modeling. In vivo Fourier transform Raman spectroscopy confirmed the presence of Trp metabolites together with H2O2 supporting deprivation of the epidermal Trp pool by Fenton chemistry. Taken together, our data support a long-expressed role for in loco redox balance and a distinct immune response. These insights could open novel treatment strategies for this disease.—Schallreuter, K. U., Salem, M. A. E. L., Gibbons, N. C. J., Maitland, D. J., Marsch, E., Elwary, S., Healey, A. R. Blunted epidermal l-tryptophan metabolism in vitiligo affects immune response and ROS scavenging by Fenton chemistry, part 2: epidermal H2O2/ONOO−-mediated stress in vitiligo hampers indoleamine 2,3-dioxygenase and aryl hydrocarbon receptor-mediated immune response signaling.

Permanent production and use of organic chemicals for many purposes has resulted in their introduction and accumulation in the environment. Depending on their physicochemical properties they can be transported by different ways from the source to very remote regions of the planet. Many organic chemicals are used in agriculture as pesticides for cultures protection or nutrient. Residues of these chemicals can always be found in fields, and under the effect of precipitations they leach and pass in streams and rivers. Pharmaceuticals and personal health care products and other house holding chemicals are continuously introduced in the environment through municipal wastewaters. These substances exhibit, in most of the cases, perturbation effects towards the living organisms, moreover the effect of many of them is not known yet. Despite their concentration in water is low, the exposure of organisms for long periods can lead to negative consequences, but these effects cannot be measured instantly. In order to reduce or avoid the pollution of water with chemicals many water treatment methods has been developed like adsorption of pollutants on adsorbents, membrane filtration, microbiological treatment, chemical oxidation with oxidizing agents and advanced oxidation processes. Most of the methods used in waste water treatment plants (WWTP) do not completely destroy the organic contaminants or they only separate the contaminants from water. Then they have to be deposed somewhere else remaining always a potential source of contamination. Advanced oxidation processes and in particular electrochemical advanced oxidation processes are methods developed later and are proven as more effective as they can completely oxidize the organic matter in water. The subject of this thesis is the use of electro-Fenton, an electrochemical advanced oxidation process for efficient destruction of organic pollutants in aqueous medium. In this method, organic pollutants are eliminated by H hydroxyl radicals (high oxidation power species) which are produced in situ through the Fenton's reagent (H2O2 + Fe2+) itself generated in the solution electrochemically and continuously. In this process, the electrode material is of fundamental importance in order to have an efficient process, so we have studied at large extent the influence of both cathode and anode material in this work. Firstly a systematic study on the oxidation capacity of the process of amoxicillin (AMX) as model pollutant with several anodes materials: BDD, Pt, DSA, PbO2 Carbon felt, Graphite and Carbon fibre was realised. In all cases a stainless steel electrode was used as cathode. The degradation of AMX was followed by HPLC analysis whereas the mineralization efficiency ot the process was measured by total organic carbon analyser (TOC). This revealed that BDD was the most efficient anode for AMX oxidation and DSA was the weakest one. Carbon felt showed a characteristic behaviour; it was very efficient on AMX oxidation but it could not transform AMX to CO2 and H2O. Afterwards four anodes were tested for their influence on electro-Fenton process efficiency namely Pt, BDD, DSA and Carbon felt, the cathode was always carbon felt. Sulfamethazine (SMT) was used as model pollutant. Apparent rate constants have given only moderate values of mineralization for currents lower than 100 mA. Here again the BDD anode was distinguished for its excellent mineralization capacity owing to the additional hydroxyl radicals and other oxidizing species introduced in the system. When electro-Fenton applied good degradation and mineralization results were obtained even with the DSA anode (...)

Numerous chemical species are important to the health of biological systems. Some species can be beneficial at low doses and harmful at high doses. Other species are highly reactive and trigger serious cell damage. Improved methods to detect the presence and activity of such species are needed. In this work, several biologically important species were studied using appropriate analytical techniques. Fluoride is an important species in human physiology. It strengthens teeth and gives protection against dental caries. However, elevated concentrations of fluoride in the body can lead to health problems such as dental and skeletal fluorosis. Reported fluoride sensors used fluorescence quenching methods in determining fluoride concentration. Our study explored synthesis and characterization of 1,8-bis(phenylthioureido) naphthalene (compound 1) as a fluoride sensing molecule. Compound 1 showed a remarkable 40 fold enhancement in fluorescence with 5 eq of fluoride addition. Compound 1 also showed possibility of visual colorimetric sensing with fluoride. Free radical mediated oxidations of biomolecules are responsible for different pathological conditions in the human body. Superoxide is generated in cells and tissues during oxidative burst. Moderately reactive superoxide is converted to peroxyl, alkoxyl and hydroxyl radicals by various enzymatic, chemical, and biochemical processes. Hydroxyl radical imparts rapid, non specific oxidative damage to biomolecules such as proteins and lipids. Superoxide also reacts with nitric oxide in cells to yield peroxynitrite, which is highly reactive and damages biomolecules. Both hydroxyl radical and peroxynitrite readily react with amino acids containing aromatic side chains. Low density lipoprotein (LDL) carries cholesterol in the human body. Elevated concentration of LDL is a potential risk factor for atherosclerosis. Previous research drew a strong correlation between oxidized low density lipoprotein (ox-LDL) and plaque formation in the arterial wall. More importantly, oxidative damage causes structural changes to the LDL protein (apo B-100) which might facilitate the uptake of LDL by macrophages. In this study LDL was exposed to various concentrations of hydroxyl radical peroxynitrite and hypochlorite. Thereafter oxidized amino acid residues in apo B-100 were mapped by LC-MS/MS methods. We found widely distributed oxidative modifications in the apo B-100 amino acid sequence.

[pt] Para remover metais de águas e efluentes aquosos, geralmente são empregados métodos tradicionais, os quais envolvem a neutralização, com posterior hidrólise e precipitação de hidróxidos, utilizando uma base.O manganês deve ser removido de águas e efluentes aquosos, até que sua concentração atinja um máximo exigido pela legislação brasileira, que é de 0,1mg/L para águas e 1mg/L para efluentes aquosos. O trabalho desenvolvido aqui investigou a remoção de manganês (II) utilizando os oxidantes: oxigênio, reagente Fenton e peróxido de hidrogênio, para procurar dentre estes um processo que fosse mais eficiente do que o de simples precipitação do hidróxido. São discutidos os resultados de ensaios realizados com a utilização de soluções sintéticas de manganês (II), cujo objetivo foi desenvolver um caminho que favorecesse a remoção deste metal, para que a concentração do mesmo tanto em águas quanto em efluentes aquosos esteja de acordo com os padrões exigidos pela legislação brasileira (resolução CONAMA 20/ 1986).Os ensaios foram realizados em pH de 7 a 10, a temperatura ambiente e em torno de 80ºC e com um tempo de reação de 5,15 e 30 minutos. Foi utilizado peróxido de hidrogênio em dosagem estequiométrica com excesso de 100% e 200%, para a reação: Mn2+ (aq) + H2O2 (aq) -> MnO2(s) + 2 H+ (aq) Dentre os testes realizados, ambos o peróxido de hidrogênio e o reagente Fenton mostraram-se bastante eficientes na remoção de manganês, permitindo atingir concentrações finais desse metal inferiores a 0,3 mg/L, a temperatura ambiente em valores de pH inferiores aos necessários para a precipitação sem oxidante, com O2. / [en] I order to remove metals from waters and aqueous effluents generally are employed traditional methods which involve neutralization, hydrolysis and precipitation of hydroxides using a base. Manganese must be removed from waters and aqueous effluents down to a concentration limited by Brazilian law which is of 0.1 mg/L for waters and 1.0 mg/L for aqueous effluents. The work carried out herein investigated the removal of manganese (II) using the following oxidants: oxygen, hydrogen peroxide, and Fenton reagent, with the aim to identify a process that could be more efficient than the simpler hydroxide precipitation. Results are discussed of experiments made with synthetic solutions of 1000 mg/L manganese (II) with the objective of developing a route that could favour the removal of that metal to the levels established by Brazilian environmental law (resolution CONAMA 20 / 1986).The experiments were conducted in pH 7 to 10, at temperature ambient and 80 oC, with reaction times of 5, 15 and 30 minutes. Hydrogen peroxide was used in excess levels of 100 and 200% for the reaction: Mn2+ (aq) + H2O2 (aq) -> MnO2 (s) + 2 H+ (aq) Amongst the conducted experiments, both hydrogen peroxide and the Fenton reagent were shown to be most effective, allowing final concentrations of manganese less than 0.3 mg/L, at ambient temperature, in pH values lower than those required for precipitation without oxidation or with O2 (air).

A presença de substâncias húmicas em águas destinadas ao abastecimento tem ocasionado diversos problemas, entre eles a formação de subprodutos halogenados, principalmente quando se emprega a pré-oxidação com cloro. Com o reagente de Fenton não há a possibilidade de formação desses indesejáveis compostos halogenados, pois o forte poder oxidativo do reagente de Fenton é devido ao radical hidroxila (OH). Aliado a isto, com o mesmo produto químico se pode ter a pré-oxidação e coagulação de compostos orgânicos, pois o reagente de Fenton consiste na aplicação de íons de Fe+2 e peróxido de hidrogênio em meio ácido, sendo o Fe+2 oxidado a Fe+3. Como esses íons formam espécies hidrolisadas que atuam como coagulantes, o reagente de Fenton pode ter a dupla função de oxidação e coagulação nos processos de tratamento. Por isso, neste trabalho foi proposta uma metodologia para emprego do reagente de Fenton como agente coagulante no tratamento de águas contendo cor elevada causada pela introdução de substâncias húmicas extraídas de turfa. Além disto, foi estudado o efeito da massa molecular das substâncias húmicas na eficiência da coagulação, floculação e flotação de águas; para isto foram preparadas 4 águas distintas apresentado a mesma cor verdadeira, mas com substâncias húmicas de diferentes massas moleculares, obtidas por fracionamento por ultrafiltração. Por meio da otimização da dosagem de coagulante e respectivo pH de coagulação e posterior construção dos diagramas de coagulação para cada água de estudo, verificou-se que a água preparada com as substâncias húmicas de menor massa molecular apresentou maior grau de dificuldade para tratamento, requerendo dosagens de coagulante (reagente de Fenton) bem mais elevadas em relação às águas preparadas com substâncias húmicas de maior massa molecular. Adicionalmente, foram realizados ensaios de filtração em areia após a flotação, procurando-se simular tratamento em ciclo completo, tendo sido constatado que com o reagente de Fenton empregado como agente coagulante, a água filtrada atendeu ao padrão de potabilidade vigente no Brasil em relação aos parâmetros medidos (cor aparente < ou = 3 uH, turbidez < 0,5 uT e ferro total residual < 0,005 mg/L). Os valores de absorvância e carbono orgânico total da água filtrada também foram muito pequenos, indicando que a formação dos subprodutos da desinfecção com cloro seriam insignificantes. / Humic substances\' presence in water destined for supply has brought many problems, such as halogenated byproducts formation, mainly when chlorine is used as preoxidant. With Fenton\'s reagent there is no formation possibility of these undesirable halogenated compounds, since the strong oxidative power of Fenton\'s reagent is due to hydroxyl radical (OH). In addition, with the same chemical product, it is possible to have the preoxidation and coagulation of organic compounds, because Fenton\'s reagent consists of Fe+2 ions and hydrogen peroxide application under acid conditions, with Fe+2 oxidized to Fe+3. Since these ions form hydrolyzed species that act as coagulants, Fenton\'s reagent can have the double function of oxidation and coagulation on treatment processes. Because of this, the current work proposed a methodology to use Fenton\'s reagent as coagulant agent in the treatment of waters having high true color caused by the introduction of humic substances extracted by peat. Besides this, humic substances molecular weight effect on coagulation, flocculation and flotation of waters was studied; for this, 4 distinct waters having the same true color were prepared, but with different humic substances molecular weights, obtained by ultrafiltration fractioning. Through optimization of coagulant dosage and respective coagulation pH and posterior construction of coagulation diagrams for each studied water, it was verified that the water prepared withthe smallest molecular weight humic substances was more difficult to treat, requiring higher coagulant (Fenton\'s reagent) dosages compared with the waters prepared with larger molecular weight humic substances. Furthermore, experiments of filtration after flotation were carried out, trying to simulate a complete cycle treatment, which verified that with Fenton\'s reagent, employed as coagulant agent, the filtered water reached the brazilian potable standards concerning the measured parameters (apparent color < ou = 3 HU, turbidity < 0.5 TU and residual total iron < 0.005 mg/L). The absorbance and total organic carbon values of filtered water were also very low, indicating that the disinfection byproducts formation with chlorine would be insignificant.

Iron oxide nanoparticles (IONPs) have been widely studied for a variety of applications, from biomedical applications (e.g., cell separation, drug delivery, contrast agent for magnetic resonance imaging and magnetically mediated energy delivery for cancer treatment) to environmental remediations (e.g., heavy metal removal and organic pollutants degradation). It has been demonstrated that IONPs can induce the production of reactive oxygen species (ROS) via Fenton/Haber-Weiss reactions which has been shown to be one of the key underlying mechanisms of nanoparticles toxicity. This inherent toxicity of nanoparticles has been shown to enhance the efficacy of traditional cancer therapies such as chemotherapy and radiation. In addition, the generation of ROS induced by IONPs has been also studied as advanced oxidation processes (AOP) for wastewater treatment. Recent research has also shown that exposure to an alternating magnetic field can significantly enhance the generation of ROS induced by IONPs. Moreover, the coatings of IONPs play an important role on the surface reactivity of nanoparticles since it can prevent the generation of ROS via Fenton chemistries at the surface of the nanoparticles. In this work, co-precipitated IONPs were functionalized with small molecules including citric acid, sodium phosphate, amino silane and dopamine. The impact of coating on surface reactivity of the as-synthesized particles was studied using methylene blue dye degradation assay under AMF exposure. With the coatings of these small molecules, the IONPs induced ROS generation was significantly decreased because of the dense surface coverage. To study the effect of polymeric coatings, a degradable poly (beta amino ester) (PBAE) polymer coating was synthesized with dopamine as an anchor to bind to nanoparticles. The surface reactivity of the particles was expected to be recovered once the polymer coating was degraded. Furthermore, the impact of non-degradable PEG-based polymer coating on surface reactivity via ROS generation was also investigated using methylene blue decolorization assay with the presence of AMF. The retention of surface reactivity of PEG-based polymer coated IONPs shows promise for cancer treatment. The application of IONPs as heterogeneous catalyst for organic contaminant degradation was investigated. Bisphenol A (BPA) was used as a model compound, and Fenton reactions were induced by IONPs with the presence of hydrogen peroxide and hydroxylamine as well as alternating magnetic field exposure. The kinetics of BPA degradation under water bath and AMF exposure at 37oC was also studied, and the results showed potential applications of IONPs for organic pollutants remediation.

Suite à leur utilisation, les médicaments sont souvent partiellement métabolisés; ainsi ces substances pharmaceutiques et/ou leurs métabolites sont rejetés continuellement dans les eaux usées. Leur présence et accumulation dans les eaux naturelles constituent une pollution émergente conduisant à la perturbation des écosystèmes et l'accroissement de mal fonctionnement de la reproduction des espèces aquatiques telles que les poissons. Parmi les polluants pharmaceutiques, les antibiotiques méritent une attention particulière parce qu'ils sont utilisés en grande quantité d'une part et constituent des molécules biologiquement actives pouvant interagir avec des cibles biologiques spécifiques conduisant à l'apparition du phénomène de résistance des micro-organismes potentiellement pathogènes tels que les bactéries (vis-à-vis de ces médicaments employés pour les combattre). Une action préventive est donc indispensable pour réduire leur présence dans les milieux aquatiques naturels.Dans ce travail nous avons appliqué le procédé électro-Fenton (EF), une méthode indirecte d'oxydation électrochimique très performante, à la dégradation des polluants pharmaceutiques sélectionnés, trois antibiotiques couramment utilisés : le sulfaméthoxazole (SMX), l'amoxicilline (AMX) et sulfachloropyridazine (SCP). Le traitement des solutions aqueuses de ces antibiotiques été réalisé en milieux aqueux acide à l'aide des radicaux hydroxyles générés électrochimiquement. Les radicaux hydroxyles sont produits in situ à courant constant dans une cellule électrochimique non divisée, munie d'une cathode tridimensionnelle de grande surface spécifique (feutre de carbone) et d'une anode de Pt ou de BDD afin de suivre la cinétique d'oxydation avec les radicaux hydroxyles et la minéralisation de leurs solutions aqueuses. Ces radicaux sont générés à travers la réaction de Fenton :H2O2 + Fe2+ + H+ → Fe3+ + H2O + *OHdans laquelle les réactifs générés (H2O2) ou régénéré (Fe2+ en tant que catalyseur) électrocatalytiquemment. L'influence des différents paramètres sur la cinétique de dégradation des antibiotiques et sur la cinétique de minéralisation des solutions d'antibiotiques a été étudiée. L'effet co-catalytique des ions Cu2+ a été aussi examiné. Les radicaux hydroxyles formés sont des oxydantes très puissants et réagissent sur les antibiotiques en question conduisant à leur minéralisation. L'étude cinétique montre que la dégradation oxydative des trois antibiotiques suit une cinétique de réaction du pseudo-premier ordre, avec des temps de dégradation assez courts. Par exemple, avec une anode de Pt, l'oxydation complète des molécules SMX, AMX et SCP a été achevée en moins de 15 min à 300 mA.Afin d'établir les voies de dégradation avec les radicaux hydroxyles, les intermédiaires aromatiques, les acides carboxyliques formés ainsi que les ions inorganiques libérés dans la solution lors du traitement ont été identifiés et leur évolution dans le temps a été suivie. Les valeurs des constantes de vitesse des réactions entre les *OH et les antibiotiques et leurs intermédiaires ont été déterminés par la technique de cinétique de compétition à l'aide d'un composé de référence, l'acide p-hydroxybenzoϊque. L'efficacité du procédé d'oxydation anodique (OA) avec une anode Pt et BDD à titre comparatif avec le procédé électro-Fenton a été aussi étudiée. L'efficacité de minéralisation des solutions aqueuses d'antibiotique à été évaluée par mesure du carbone organique total (COT). Le suivi de la toxicité lors du traitement des solutions d'antibiotiques par la méthode Microtox®, (une méthode basée sur la mesure de la luminescence des bactéries marines Vibrio fischeri) a montré la formation des intermédiaires plus toxiques que les molécules mères.L'ensemble des résultats obtenus confirme l'efficacité du procédé électro-Fenton pour la dépollution des effluents aqueux chargés d'antibiotiques

Ce travail de thèse est axé sur l'élaboration de techniques de bioremédiation des sols contaminés par les Polluants Organiques Persistants (POP) en particulier sur deux familles de polluants : les Hydrocarbures Aromatiques Polycyliques et les dioxines (PCDD/F). La dégradation des POP présente deux obstacles majeurs à l'efficacité des traitements biologiques par voie fongique : la faible biodisponibilité des POP et la difficulté d'amorcer l'oxydation de molécules aussi stables chimiquement. Afin de lever ces verrous technologiques, nous proposons de coupler une oxydation chimique douce à l'oxydation biologique par les champignons telluriques saprotrophes et d'utiliser l'amidon pour améliorer la proximité spatiale entre le polluant et les réactifs d'oxydation. La première partie de ce travail de thèse consiste à fonctionnaliser de l'amidon de pomme de terre par la 1,4-butane sultone et l'anhydride 2-octén-1-ylsuccinique selon différentes conditions de synthèses. En comparaison avec l'amidon natif, un des produits obtenus, P9*, possède des propriétés surfactantes très intéressantes pour notre étude. En effet, P9* augmente la solubilité aqueuse de l'amidon par un facteur de 35 (22,60 g.L⁻¹) et stimulent 33 fois la solubilisation aqueuse du benzo[a]pyrène (BaP). Pour la seconde partie, l'utilisation d'un système d'étude simplifié où le champignon est cultivé en milieu minéral en conditions axéniques nous a permis de déterminer les paramètres (souche fongique, type et dose d'oxydant chimique) optimaux pour l'élaboration d'une méthode de dégradation des POP au laboratoire. Des études comparatives de dégradation du BaP sont donc réalisées in vitro par différents processus d'oxydation chimique (réaction de Fenton) et/ou biologique. Le couplage des deux procédés conduit à une dégradation du PaP de 40,0%. De plus, l'encapsulation du BaP par les nanosphères d'amidon P9* permet une dégradation du polluant de 64,6% par le réactif de Fenton. Deux souches fongiques (Penicillium brasilianum et Fusarium solani) sont ensuite utilisées pour des essais de dégradation conduits au laboratoire en microcosmes de sols historiquement contaminés par les PCDD/F. L'inoculation de la souche endogène P. brasilianum en présence de copeaux de carton comme agent structurant a conduit à une diminution de la toxicité des PCDD/F de 40,5% après seulement 2 mois d'incubation par rapport au sol témoin. Ce travail de thèse ouvre ainsi de nouvelles perspectives de techniques de remédiation des sols pollués par les POP à faible coût économique et respectueuses de l'environnement. / This thesis work deals with the development of bioremediation techniques for contaminated soils by Persistent Organic Pollutants (POPs) such as : Polycyclic Aromatic Hydrocarbons and dioxins (PCDD/F). The degradation of POPs has two main obstacles to efficient biological treatments by fungi : the low bioavailability of POPs and the difficulty of initiating the oxydation of molecules as stable as others. To overcome these technological barriers, we propose to couple a mild chemical oxidation to biological oxidation by saprotrophic telluric fungi and to use starch to improve the spatial proximity between the pollutant and oxidizing reagents. The first part of this study is to functionalize native potato starch by 1,4-butane sultone and 2-octenyl-1-succinic anhydride according to different synthesis conditions. In comparison with native starch, one of the processed products, P9*, has very interesting surfactant properties for our study. Indeed, P9* increases starch apparent aqueous solubility by a factor of 65 (22.60 g.L⁻¹) and stimulates 33-fold benzo[a]pyrene (BaP) aqueous solubilization. For the second part, the use of a simplified study system where the fungus is cultivated in mineral medium under axenic conditions allowed us to determine the best parameters (fungal strainsn type and dose of chemical oxydant) for the development of a POPs degradation method in the laboratory. Comparative studies of BaP degradation are therefore carried out in vitro by different processes of chemical (Fenton's reagent) and/or biologial oxidation. The coupling of the two processes leads to a BaP degradation of 40.0%. Moreover, the BaP encapsulation by starch nanospheres P9* allows a pollutant degradation of 94.6% by the Fenton reagent. Two fungal strains (Penicillium brasilianum and Funsarium solani) are then used for the degradation lab experiment in historically PCDD/F contaminated soil microcosms. the inoculation of the endogene strain P.brasilianum in presence of cardboard chips as a bulking agent led to a decrease in PCDD/F toxicity of 40.5% after only two months of incubation compared to the controm soil. This PhD work draws new perspectives for remediation techniques of contaminated soils by POPs that are cost-effective and environmentally friendly.

Orientador: Marcos Roberto de Vasconcelos Lanza / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-10T15:24:47Z (GMT). No. of bitstreams: 1 Rocha_RobsondaSilva_M.pdf: 1261455 bytes, checksum: df1d32d1e649b02714911e4465f4c58e (MD5) Previous issue date: 2007 / Resumo: Este projeto propõe o desenvolvimento e a otimização do tratamento eletroquímico de um efluente farmacêutico sintético contendo diclofenaco sódico. Neste trabalho foram executadas duas etapas, iniciando-se pelo estudo das reações redox do diclofenaco e, em seguida, pelo processo de degradação em um reator eletroquímico de bancada. No estudo eletroquímico do diclofenaco foram realizadas voltametrias hidrodinâmicas em meio aquoso (0,1 M de K2SO4) e meio não aquoso (N,N Dimetil Formamida, DMF, com 0,1 mol.L-1 de perclorato de sódio), no eletrodo de carbono vítreo e nas rotações de 0 rpm a 3000 rpm. O eletrodo de Carbono Vítreo em meio não aquoso apresentou as melhores respostas, foram observados dois picos de oxidação, -0,33 V vs. Ag/AgCl e 0,57 V vs. Ag/AgCl e um pico de redução em 0,73 V vs. Ag/AgCl. O estudo das voltametrias hidrodinâmicas mostrou, que as reações de oxi-redução do diclofenaco são influenciadas pela rotação do eletrodo de carbono vítreo. Na degradação do diclofenaco sódico foi utilizado um reator eletroquímico de bancada, como catodo utilizou-se um eletrodo de difusão gasosa e como anodo, um DSA-Cl2 ®, como eletrólito foi utilizado 1,0 L de K2SO4 0,1 M com 200 mg.L-1 de Diclofenaco, com uma vazão de 200 L.h-1, a pressão de O2 foi de 0,2 Bar e os ensaios no reator foram realizados com e sem 10 mM de FeSO4. Os resultados mostraram que o reator eletroquímico é eficiente na geração de H2O2 alcançando 350 mg.L-1 em duas horas de eletrólise sem a adição do fármaco. Os ensaios de degradação do diclofenaco utilizaram a oxidação química indireta, pelos radicais hidroxila formados a partir do H2O2 eletrogerado, e pela oxidação eletroquímica direta no anodo. Este processo se mostrou eficiente na degradação do diclofenaco, alcançando 99,2 % de redução da concentração inicial do fármaco e 27,4 % de redução da demanda química de oxigênio (DQO). Quando se utilizou eletro-Fenton, adição de FeSO4, como catalisador da formação de radicais hidroxila, a eficiência aumentou, a degradação do diclofenaco alcançou 99,4 % da concentração inicial e a diminuição da DQO chegou a 63,2 %. Os resultados mostraram que o processo de degradação utilizando reator eletroquímico é eficiente na degradação do fármaco e na diminuição da DQO / Abstract: This work proposes the development and the optimization of the electrochemical treatment of a synthetic effluent with sodium diclofenac. In this work two stages were executed the study of the redox reactions of the sodium diclofenac and, the process of this organic compound. Hydrodynamic voltammetry experiments were recorded to identity sodium diclofenaco redox reaction in a non-aqueous medium (DMF with 0,1 mol L-1 of NaClO4) and in aqueous medium (0.1 M of K2SO4). These experiments were performed using glassy carbon as working electrodes, at different rotations (0 up to 3000 rpm). The glassy carbon electrode in non aqueous medium presented the best answers, where observed two peaks of oxidation, at 0.33 V vs. Ag/AgCl and 0.57 V vs. Ag/AgCl, and a peak of reduction at 0.73 V vs. Ag/AgCl. The hydrodynamic voltammetry it experiments showed that the redox reactions of the sodium diclofenac are influenced by the rotation of the glassy carbon electrode. A flow electrochemical reactor was used for the sodium diclofenac degradation. It was used a gas diffusion electrode as cathode and DSA-Cl2 ® as anode. The electrolyte used was 1.0 L of 0.1 M K2SO4 with 200 mg L-1 of sodium diclofenac (flow rate: 200 L.h-1, pressure (O2): 0,2 Bar), with and without 10 mM of FeSO4. The performance was evaluated considering concentration decay of sodium diclofenac concentration (HPLC) and chemical oxygen demand (COD) as a function of the applied current and addiction of Fe(II) ions. The results showed that the electrochemical reactor was efficient in the generation of 350 mg L-1 of H2O2 after two hours of electrolysis without the addition of the organic compound. The sodium diclofenac degradation occurred by indirect chemical oxidation, for the hydroxyl radicals formation from H2O2 electrogenerated, and by direct electrochemical oxidation on anode. This process showed the efficiency in the degradation of sodium diclofenaco: 99,2 % of reduction of the initial concentration and 27,4 % of reduction of the chemical oxygen demand (COD). When electro-Fenton was used by addition of FeSO4 as catalyst hydroxyl radicals formation, the degradation efficiency increased. The of the drug degradation was 99,4 % of the initial concentration and the COD reduction was 63,2 %. The results showned that the degradation process using electrochemical reactor was efficient in the sodium diclofenac degradation and COD reduction / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica