Chloride anion effect on the advanced oxidation process of methidathion and dimethoate: role of Cl2¿- radical.

Autores UPV
Revista Water Research


The reaction of phosphor-containing pesticides such as methidathion (MT) and dimethoate(DM) with dichloride radical anions ¿Cl 2 was investigated. The second order rate constants (1.3 0.4) 108 and (1.1 0.4) 108 M1 s1 were determined for the reaction of Cl 2 with MT and DM, respectively. A reaction mechanism involving an initial charge transfer from the sulfide groups of the insecticides to Cl 2 is proposed and supported by the identified transient intermediates and reaction products. The formation of chlorinated byproducts was determined. The unexpected consequences of an efficient Cl2 reactivity towards MT and DM on the degradation capacity by Advanced Oxidation Procedures applied to polluted waters containing the insecticides and Cl anions is discussed.