Application of titanium dioxide as photocatalyst in diuron degradation: operational variables evaluation and mechanistic study

ABSTRACT

Diuron (DI) is a herbicide used in agricultural fields for weed control that can cause skin irritations and carcinogenic problems. In this study, heterogeneous photocatalysis was used for the degradation of the DI applying TiO₂ as catalysts in a batch reactor. Experimental designs were performed to evaluate the influence of pH, catalyst concentration and substrate, also to maximize DI degradation results. After 3 hours of reaction, it was possible to observe that pH was the variable with the significant influence on the degradation of the DI using TiO₂ as a catalyst. With the mechanistic study it was possible to propose that the degradation of this herbicide is carried out by the hydroxyl radicals generated from the O₂ reduction. The statistical models performed in this study can be applied to improve the process of treatment of industrial and agricultural effluents using heterogeneous photocatalysis.

Keywords:
photocatalytic; diuron; experimental design; optimization