Removal of organophosphorus pesticides from water by electrogenerated Fenton's reagent

Aqueous solutions of organophosphorus pesticides were completely mineralized via in-situ generated hydroxyl radicals (HO^·) by the Electro-Fenton process. Formation of Fenton's reagent (H₂O₂, Fe²⁺) was carried out by simultaneous reduction of O₂ and Fe³⁺ on carbon cathode in acidic medium. The electrochemistry combined with Fenton's reagent provides an excellent way to continuously produce the hydroxyl radical, a powerful oxidant. We demonstrate the efficiency of the Electro-Fenton process to degrade three organophosphorus insecticides: malathion, parathion ethyl and tetra-ethyl-pyrophosphate (TEPP). Degradation kinetics and removals of chemical oxygen demand (COD) have been investigated. Here we show that the mineralization efficiency was over 80% for three organophosphorus pesticides.