Síntese e caracterização de tungstato de ferro (FeWO4) e tungstato de zinco (ZnWO4) para aplicações tecnológicas

Detalhes bibliográficos
Ano de defesa: 2015
Autor(a) principal: Severo, Eric da Cruz
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Santa Maria
BR
Engenharia de Processos
UFSM
Programa de Pós-Graduação em Engenharia de Processos
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://repositorio.ufsm.br/handle/1/7997
Resumo: In this study, two tungsten-based oxides, iron tungstate (FeWO4) and zinc tungstate (ZnWO4), were synthesized by the routes microwave-assisted hydrothermal and solvo-hidrothermal, respectively. The iron tungstate oxide was used as a catalyst in heterogeneous photo-Fenton reaction for removal of Amaranth dye, whereas the zinc tungstate was used as a support for the immobilization of inulinase by adsorption process. Both materials produced were characterized by techniques such as X-ray diffraction (XRD), nitrogen adsorption-desorption analysis by Brunauer-Emmett-Teller method (BET), Fourier transform infrared spectroscopy (FTIR) and particle size distribution analysis by laser diffraction. For heterogeneous photo-Fenton reaction, an experimental design was used to study the effect of variables such as pH, hydrogen peroxide concentration and dye concentration on the degradation efficiency of Amaranth dye. The inulinase immobilization on the ZnWO4 oxide was investigated in two temperatures. According to the characterization results, both synthesized material has a porous structure and high crystallinity. The FeWO4 oxide showed a satisfactory ability to degrade amaranth dye, and under the optimum reaction conditions, 97% decolorization and 58% mineralization were obtained. Furthermore, the efficiency and stability of this catalyst were maintained high after five cycles of reuse. The ZnWO4 oxide showed a satisfactory inulinase adsorption, where the best result was found to be 605 U.g-1 at 30 oC.