RESUMO

The effect of combining the photocatalytic processes using TiO2 and the photo-Fenton reaction with Fe3+ or ferrioxalate as a source of Fe2+ was investigated in the degradation of 4-chlorophenol (4CP) and dichloroacetic acid (DCA) using solar irradiation. Multivariate analysis was used to evaluate the role of three variables: iron, H2O2 and TiO2 concentrations. The results show that TiO2 plays a minor role when compared to iron and H2O2 in the solar degradation of 4CP and DCA in the studied conditions. However, its presence can improve TOC removal when H2O2 is totally consumed. Iron and peroxide play major roles, especially when Fe(NO3)3 is used in the degradation of 4CP. No significant synergistic effect was observed by the addition of TiO2 in this process. On the other hand, synergistic effects were observed between FeOx and TiO2 and between H2O2 and TiO2 in the degradation of DCA.

Assuntos

Clorofenóis/isolamento & purificação , Corantes/química , Ácido Dicloroacético/isolamento & purificação , Irrigantes do Canal Radicular/isolamento & purificação , Titânio/química , Poluentes da Água/isolamento & purificação , Purificação da Água/métodos , Clorofenóis/química , Ácido Dicloroacético/química , Peróxido de Hidrogênio/química , Ferro/química , Análise Multivariada , Fotoquímica , Irrigantes do Canal Radicular/química , Luz Solar