No abstract

In this work, a photocatalytic tubular reactor, with a nanometric TiO2/ZrO2 film, immobilized on glass substrate, was developed in order to investigate the degradation of volatile organic compounds, such as, benzene, toluene, ethylbenzene and xylene (BTEX ) in groundwater sample, under black light irradiation (365nm). The BTEX compound were determined by solid phase microextraction (SPME) technique and analyzed by Gas Chromatography - Ionization Flame Detection (CG-FID). The efficiency of photocatalytic process was evaluated by determination of BTEX removal and toxicity, using Daphnia similis as organism-test. The influence of the initial concentration of BTEX in the degradation process was investigated. The degradation process of sample groundwater contaminated with BTEX (145μg/L) from gasoline, resulted in 90% of efficiency after 120 minutes of treatment. The toxicity (EC50-48 h) of the groundwater sample to Daphnia similis was 14.1% (10.5-19.0) for untreated samples. After 30 min of treatment, the EC50-48 h was of 84.3 (71-100%). The benzene efficiency removal was reduced in function of the increase of its initial concentrations that observation was not found for the other compounds studied.

The transmission of Huanglongbing (HLB) disease on citrus plants is through dissemination of the bacteria Candidatus Liberibacter ssp, by Diaphorina citri psyllid, its insect vector. Chemical control of the psyllids, and thiamethoxam (neonicotinoid insecticide) is one of the active ingredients used in the control of HLB. This insecticide is water soluble, unstable and rapidly degraded by photolysis. Pesticide nanoformulation is one of the strategies to control release of active compound as well as protection for premature degradation. Thus, studies of the effectiveness of encapsulated pesticide formulations are extremely important for enabling its use in agriculture. This study reports the encapsulation of the insecticide thiamethoxam in polymeric particles from poly-ε-caprolactone (PCL) and chitosan by double emulsion and solvent evaporation method using different concentrations of chitosan and two Pluronic (poloxamer) copolymers, F 127 and F68. These nanoparticles were characterized in terms of size, zeta potential, polydispersity, and encapsulation efficiency. The encapsulation efficiency, measured by liquid chromatography was 34%. The nanoparticles obtained from optimized conditions resulted in homogeneous and monodisperse particles with a positive superficial charge. The microalgae Raphidocelis subcapitata (bioindicator chloroficea) and microcrustacean Artemia salina, were used to evaluate the ecotoxicity of nanopesticide in comparison to pesticide already in the market. The ecotoxicity study demonstrated that nanopesticide was less toxic that commercial formulations in the studied conditions.

Dedico esta tese ao Sérgio, por caminhar ao meu lado, por existir em minha vida.... Aos meus paisAlessandro e Francesca, Ao meu irmão Caetano, pelo amor, carinho e compreensão... xi AGRADECIMENTOS Ao prof. Dr. Nelson Durán pela orientação, amizade e confiança ao longo de todo este trabalho. Ao meu grande amigo e colaborador, Dr. Benigno Sanchéz Cabrero, pela amizade, incentivo e disposição em me ajudar durante todo o desenvolvimento desta tese. Ao Dr. Alfonso Vidal pela amizade e grande ajuda na discussão deste trabalho.Ao prof. Dr. Fábio Augusto por ceder a estrutura de seu laboratório para os experimentos de cromatografia gasosa.À Raquel (Ciemat-Madrid) e ao pessoal da Plataforma Solar de Almería (Pilar, Loreto, Wolfgang e Leonidas) pelo apoio durante minha estadia no laboratório.

e apoio, fatores determinantes que me levaram a encontrar o caminho a ser trilhado para buscar cada vez mais o meu crescimento profissional e intelectual.A Claudia, minha grande amiga, por estar presente em meu caminho, por tudo ... A Paula, cuja distancia fisica se torna tao pequena diante de tamanha cumplicidade ... A todos os meus amigos da FEC e do I.Q., pelo agradavel convivio e apoio durante o periodo de trabalho, mas principalmente pelas amizades conquistadas, que me foram tao valiosas e muito me acrescentaram como profissional e como ser humano: Ileana,