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-m ethylthiophenyl-N-methylcarbamate ''mercaptodimetur'' and 2((ethylthio )methyl)phenyl-N-methylcarbamate ''ethiofencarb'' was studied in aceto nitrile/water mixture as a solvent with anthraquinone as a photosensit izer. The photoproducts obtained and the reduction potential of the ph otoexcited sensitizer are in agreement with a primary mechanism involv ing an electron-transfer from the pesticide to the excited photosensit izer. These results show that an electron-acceptor photosensitizer may increase the rate of photodegradation and help to completely remove t he pollutant.