Effect of inorganic ions on the oxidation of dichlorvos insecticide with Fenton's reagent

This study analyzes the oxidation of dichlorvos with Fenton's reagent in solutions containing various ions. Results show that the larger the added amount of ferrous ions, the higher the elimination rate of dichlorvos and the oxidization rate after the addition of ferric ions is far smaller than that of adding ferrous ions. Anions suppress the decomposition of dichlorvos in the following sequence: H2PO4- > > Cl- > NO3- similar to ClO4-. It can be seen that the Fenton reaction is extremely sensitive to anions, and phosphate ions in particular will seriously suppress the Fenton system's ability to oxidize dichlorvos. The main reason for the suppression of phosphate ions is that phosphate ions will produce a complex reaction together with ferrous ions and ferric ions, which then lowers its ability to catalyze hydrogen peroxide. (C) 1997 Elsevier Science Ltd.