Photodegradation study of the antifouling booster biocide dichlofluanid inaqueous media by gas chromatographic techniques

The aquatic photochemical behavior of the biocide dichlofluanid has been st udied under natural sunlight conditions as well as under artificial solar i rradiation in different types of natural waters (sea, river and lake water) as well as in distilled water. In order to examine the effect of dissolved organic matter (DOM), the photodegradation of the tested biocide was inves tigated also in the presence of various concentrations of humic and fulvic acids. It was found that the photodegradation proceeds via first-order reac tion in all cases and that the presence of various concentrations of DOM in hibits the photolysis reaction. Kinetic experiments are monitored with GC-E CD with half-lives varied between 8 and 83 h. The major photo decomposition products identified by GC-MS were dichlorofluoromethane, aniline, and DMSA . Based on this byproduct identification a possible degradation pathway is proposed for the photolysis of dichlofluanid in aqueous media. (C) 2001 Els evier Science B.V All rights reserved.