TiO2 photocatalyzed degradation of diazinon in an aqueous medium

Abstract

The photocatalytic degradation of diazinon was studied over TiO2catalysts. The kinetics obtained demonstrated that powder titania (t1/2= 9.7 min) was more efficient compared to pure titania thin film catalysts (t1/2= 29.4 min). Mineralization of organic carbon to CO2 after 360 min of irradiation was found to be 75% while heteroatoms (P, S, N) were mineralized into phosphate, sulfate and nitrate ions, respectively. A microtox test was performed to evaluate the toxicity of solutions treated by catalysts. Illumination of diazinon in the presence of TiO2 gave rise to several intermediates that have been identified by means of solid phase extraction and gas chromatography-mass spectrometry, while a simple degradation pathway is proposed. © Springer-Verlag 2005.