DEGRADAÇÃO FOTOCATALITICA DE PESTICIDAS ORGANOFOSFORADOS MEDIANTE O USO DE TiO₂/UV EM AMBIENTE SATURADO

• Ano de defesa: 2014
• Autor(a) principal: Ferreira, Iza Natália Moraes
• Orientador(a): NUNES, Gilvanda Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Maranhão
• Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA/CCET
• Departamento: QUIMICA
• País: BR
• Palavras-chave em Português: Pesticida; Dioxido de titânio; Degradação fotocatalítica
• Palavras-chave em Inglês: Pesticide; Titanium dioxide; Photocatalytic degradation
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://tedebc.ufma.br:8080/jspui/handle/tede/999

Pesticides that are used to combat pests in plantations operate in parallel on other species causing serious problems to be toxic and remain in the environment for a long time. This study aimed to evaluate the photocatalytic degradation of an organophosphorus pesticide by advanced oxidation processes, the insecticide methyl parathion were selected (PM), widely used in Brazilian crops, especially Maranhão. The POA consisti the application of immobilized TiO₂ as photocatalyst and UV radiation to accelerate the degradation of the pesticide. Effects of some parameters such as the illumination time and initial concentration of the compounds during photocatalytic degradation were studied. Was optimized a method for pesticide analysis by liquid chromatography and two advanced reviews (POA) for the destruction of this contaminant oxidation processes. The POA tested were: combination TiO₂/UV and TiO₂/H₂O₂/UV. The analytical method was suitable for evaluation of the POA, with limits of detection and quantification limits of 0,05 mg Lˉ¹ and 0,17 mg Lˉ¹, respectively, this method was then applied to monitoring the concentrations of the pesticide during application of POA procedures. Among the POAs, both cases showed good results in catalytic destruction of pesticide, where 100% of the pesticide was removed immediately first 30 min of exposure to UV radiation. The results showed that the efficiency of photodegradation of PM increases with increasing illumination time and photodegradation efficiency decreases with an increase in the initial concentration of PM.