Photosensitized oxidative degradation of pesticides

The photosensitized oxidative degradation of the three pesticides : 1,1-dichloro 2,2-bis (4-ethylphenyl)ethane “perthan”, 3,5-dimethyl-4-methylthiophenyl-N-methylcarbamate “mercaptodimetur” and 2((ethylthio)methyl)phenyl-N-methylcarbamate “ethiofencarb” was studied in acetonitrile/water mixture as a solvent with anthraquinone as a photosensitizer. The photoproducts obtained and the reduction potential of the photoexcited sensitizer are in agreement with a primary mechanism involving an electron-transfer from the pesticide to the excited photosensitizer. These results show that an electron-acceptor photosensitizer may increase the rate of photodegradation and help to completely remove the pollutant.