Removal of Mixed Pesticides from Drinking Water System Using Surfactant-Assisted Nano-TiO2

The present study focused on the degradation of mixed pesticides using UV-induced photocatalytic degradation of lindane (1 alpha,2 alpha,3 beta,4 alpha,5 alpha,6 beta-hexachlorocyclohexane), methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothioate), and dichlorvos (2,2-dichlorovinyl-O-O-dimethyl phosphate). Different grades of TiO2 were prepared through the acid route (AR), alcohol route (AlR), and surfactant route (SR) and their photocatalytic activity were compared with commercially available Degussa P-25 TiO2. The rate of degradation of pesticides was high for TiO2 prepared through the SR compared to the other three catalysts. The crystalline structure and morphology of SR TiO2 was identified with scanning electron microscope, energy dispersive X-ray analyzer, UV, and transmission electron microscope analyses and was compared with that of Degussa P-25 TiO2. Degradation studies of individual as well as mixed pesticides were carried out. The intermediate formed during the photodegradation of methyl parathion, lindane, and dichlorvos were identified by gas chromatography-mass spectrometry analysis.