Mineralization of Organophosphorous Pesticides by Electro-generated Oxidants

Abstract

In this study we have investigated organophosphorous pesticides destruction by oxidizing system, which was synthesized in the polluted aqueous sulfuric acidic solutions by constant current conducting. Bulk electrolyses with lead electrode were performed in an undivided cell under amperestatic conditions to study the oxidative cleavage of commercial pesticides and pure active ingredients. The pesticides were completely destroyed following pseudofirst-order kinetics estimated according to chemical oxygen demand (COD) data and phosphate ions accumulation. The assessment of decay rate constants shows the high mineralization degree. Moreover, the general current efficiency corresponds to high impact of chemical reactions in the bulk along with electrochemical interactions and defines the reasonable treatment process time as 120 min. The decay rate constants obtained by phosphate formation are higher for glyphosate than rate constants estimated by COD. It may be explained by P-C bond breaking and phosphate ions cleavage. For further study of organophosphorous pesticides oxidation pathways in detail by described process, the conditions of electrolysis should be milder.