ELECTROCHEMICAL DESTRUCTION OF METHIDATHION BY ANODIC OXIDATION USING A BORON-DOPED DIAMOND ELECTRODE

The degradation of insecticide methidathion (organophosphorous pesticide) in aqueous medium has been studied by anodic oxidation using a boron-doped diamond (BDD) anode. The results obtained show that the application of electrolysis of pesticide allows to reduce the chemical oxygen demand (COD). For 2 % NaCl and 3 % NaCl solutions the achieved reduction was 85 % and 72 % respectively. In all cases, the pH of electrolysis was significantly reduced after 45 min. The COD of methidathion solution was observed to fall with pseudo first-order kinetics. An increasing of applied current leads to an increase of the rate of electrochemical oxidation process. The effect of temperature shows that for 25 °C and 65 °C the achieved reduction was 85 % and 66 % respectively. The activation energy indicates that the process of electrochemical degradation is a complex one.