Review of strategies for modelling the environmental fate of pesticides discharged into riverine systems
Abstract
Pesticides are often produced and stored in large quantities near rivers posing a potential hazard for the aquatic environment. Accidental incidents such as storage facility fires are of major concern as significant amounts of pesticide chemicals can enter the nearby riverine System, possibly causing considerable environmental damage. This paper discusses and reviews the major physical, chemical, and microbiological fate processes of selected herbicides in riverine Systems. Glyphosate, paraquat, and diquat herbicides have been selected for discussion as they are widely used and because they degrade in freshwater mainly by well-defined fate processes. The paper concentrates on biodegradation, Sorption, and photolysis, the primary fate processes by which these herbicides degrade. Strategies for mathematically modelling the environmental fate of pesticides in rivers are reviewed and areas of future work identified.