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PHOTOCHEMICAL FATE OF AGROCHEMICALS IN NATURAL WATERS
Citation:
Zepp, R. PHOTOCHEMICAL FATE OF AGROCHEMICALS IN NATURAL WATERS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/D-91/131 (NTIS PB91216226).
Description:
Agrochemicals are introduced into aquatic environments through direct application or through indirect pathways such as runoff, partitioning into condensed phases in the troposphere, and atmospheric deposition into freshwater and marine systems. unlight-induced direct and indirect photoreactions are an important sink for agro-chemicals in such environments. oth laboratory and field studies have been conducted to develop and test concepts and mathematical relationships that describe environmental photoreactions. hese efforts achieved early success in the case of photoreactions that involve the direct absorption of solar radiation by agrochemicals. irect photo-reactions, however, account for only a part of these sunlight-induced reactions. ecent studies have shown that other reactions involving photochemically produced reactive chemical transients also are an important fate for many agrochemicals. hese include hydroxyl, hydroperoxyl/superoxide, organoperoxyl, carbonate, and dibromide ion radicals as well as singlet molecular oxygen and solvated electrons. ydrogen peroxide, a widely distributed oxidant in the sea, fresh waters, and cloud water that is produced via the intermediacy of superoxide radicals, may be involved in the oxidation of agrochemicals by the Fenton reaction or by peroxidase-catalyzed oxidations.