Abstract
Thirty two organic pesticides were screened for the reaction with ozone in water and their products were identified. Organophosphorous, acid amides, thiobencarb, isoprothiolane and pendimethaline showed high reactivity with ozone. Reactivity of N-methylcarbamates depended on the alkyl group substituted on the benzene ring. Simazine, Oxadiazon and diphenyl ethers showed low reactivity. Some pesticides with electrophilic groups fully substituted on the benzene ring showed less reactivity with ozone. From the result of the identified ozonation product, oxidation of thiophosphoryl bond, oxidation of side-chain of alkyl group and N-alkyl group, dealkylation, hydrolysis, dehalogenation etc. were considered to occurr. Most organic pesticides tested were not completely decomposed into inorganic compounds such as CO2 by ozonation. These results suggested that the decomposed products of pesticides remain in water after treatment with ozone at low concentration.
