Anodic oxidation of Methidation at boron-doped diamond electrode and degradation mechanism

This paper presents the study of the electrochemical oxidation of the insecticide Methidathion organophosphorous pesticide, using a boron-doped diamond (BDD) anode. The influence of current density, sodium chloride concentration, temperature and initial Methidathion concentration on the rate of COD abatement has been followed. The electrolyses were performed by using a solution composed of an electrolyte support (2% NaCl) and 1.4mM of Methidathion. Samples were taken during the electrolyses and analysed by UV-vis spectra and chemical oxygen demand (COD). Under laboratory conditions, the electrochemical oxidation removed 85% COD of this pesticide with a specific energy consumption of 0.12 kWhgODC-1. The electrochemical oxidation could be used as a pretreatment methode of the pesticides detoxification. In conclusion the degradation mechanism of Methidathion was carefully studied based on the formation of free radical.