Concepedia

Abstract

The development of new electrochemical and photochemical methods for the decontamination of natural water containing significant concentrations of aromatic pesticides is described. The electrochemical method is based on the electro-Fenton process, i.e. the simultaneous reduction of O2 and Fe3+ ions. Hydroxyl (OH.) radicals are electrosynthesized in aqueous solutions, followed by complete mineralization of the initial pollutants. The photochemical methods involve either a direct photodegradation reaction of pesticides by UV light, or indirect photodegradation processes including H2O2 photolysis or photo-Fenton reagents (H2O2/ Fe3+ ). Examples of the application of these methods to chlorophenoxy acid herbicides and four aromatic pesticides (bendiocarb, pirimiphos-methyl, coumatetralyl, chlorophacinon) in aqueous media are given. Environmental applications are also presented. The performances of electrochemical and photochemical methods are compared.