Photocatalytic degradation of organophosphorus pesticides using thin films of TiO2

This paper studies the feasibility of photocatalytic degradation of organophosphorus pesticides using thin films of TiO2. The results show that 0·65 × 10−4mol dn−3 of dichlorvos, monocrotophos, phorate, parathion can be completely photocatalytically degraded into PO within a short time under illumination with a medium pressure mercury lamp of 375 W. The effect of parameters such as he amount of TiO2 attached, initial concentration of organphosphorus pesticides, initial pH, amount of air flow, concentrations of H2O2 and Fe3+ on the photocatalytic degradation are studied. The possible mechanisms of photocatalytic degradation are discussed. It is our assumption that the degradation reactions occur on the surface of TiO2 via primary produced oxidizing species such as the OH radical and O , after 80 h illumination, there is no significant loss of the photocatalytic activity of TiO2.