Electrochemical and quantum studies of the radicalizing mechanism for electrodegradation of methidation pesticide

Abstract

We will study in this paper the influence of the current density on the oxidation of Methidathion for values of i equal to 20mA/cm², 40mA/cm² and 60mA/cm². For the realization of this work, we chose the electrode of boron doped diamond (BDD). It is recognized like anodes of high oxygen overpressure, support of this fact the generation of the radicals hydroxyls (OH•) by the oxidation of water. The study shows that has better current density applied for the degradation of Methidathion is 60mA/cm². The acceleration of the kinetics of degradation of Méthidathion associated the increase of current, can be explained by a more production important of radicals OH•.

A theoretical part also was carried out using the calculation Gaussian 03W program. We determined the geometry of this molecule, the point charges for determine be various points of adsorption of the molecule on the surface of the electrode and we also determined the profile energetic of molecule of Methidathion to confirm that the mechanism is concerted, indeed, no stable intermediary was theoretically localized. These calculations were carried out by method RHF on the level 6-31+G(2d, 2p).