SOLAR PHOTOCATALYTIC MINERALIZATION OF PESTICIDES IN POLLUTED WATERS

Results are presented on the solar, titanium-dioxide-photocatalyzed degradation of pesticides in rinse waters of agricultural sprayers and in heavily polluted well water. The half-life time of solar photomineralization in the 100 ppb to 50 ppm concentration range was less than 1 h for most of the pesticides. Comparison of the reaction in open and polyethylene-film-covered vessels showed that efficient photodegradation also occured in sealed systems. Samples of polluted waters prepared from liquid commercial pesticide formulations were also purified effectively by the titanium-dioxide-catalyzed solar photomineralization. The photodegradation of anionic detergents within the formulations was also observed. These results demonstrate the potential of solar photocatalytic oxidation in the removal of organic pollution in water and its practical value in the purification of highly polluted agricultural rinse waters.