Fate of Pesticides in Aquatic Environments

Abstract

Drinking water supplies are based in Germany on subsurface and to a minor extent on surface water. Both types of water resources may be contaminated by pesticides. These include among others triazines, urea derivatives, carbamates sulfonylureas and phenoxy alkane carboxylic acids, halogenated hydrocarbons and organic phosphorus derivatives. For a risk assessment of surface and ground water contamination, the occurrence and fate of these chemicals in aquatic environments is to be considered. It requires detailed knowledge of the flow regime and of the geochemical behaviour of the pesticides in water and soil with respect to the physical, chemical and microbial processes controlling their persistence and transport in the different aquatic systems. These processes can be summarized as dissolution/precipitation, complexation, adsorption/desorption, filtration, degradation (oxidation/reduction, photolysis (in surface water), hydrolysis, metabolism), transport (including spray drift, volatilisation and gas exchange) processes. The consequences for pesticide use and for future research needs are discussed.KeywordsGround WaterUnsaturated ZoneRetardation FactorChlorinate HydrocarbonCapillary BarrierThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.