Oxidation of the pesticide atrazine at DSA® electrodes

This paper presents the study of the electrochemical oxidation of the pesticide atrazine at a Ti/Ru0.3Ti0.7O2 dimensionally stable anodes (DSA®). The effect of using different supporting electrolytes (NaCl, NaOH, NaNO3, NaClO4, H2SO4 and Na2SO4) during the galvanostatic electrolysis of atrazine was investigated. It was observed that the removal of atrazine and total organic carbon (TOC) was only achieved at appreciable rates when NaCl was used as the supporting electrolyte, due to the oxidising species formed in this electrolyte (e.g. ClO−). Variation of the NaCl concentration demonstrated that, although only low concentrations of NaCl are necessary to result in the complete removal of atrazine in solution, TOC removal is almost linearly dependent on the quantity of NaCl in solution. Examination of the applied current density indicates that the efficiency of TOC removal reaches a maximum at 60 mA cm−2. Testing of alternative electrode materials containing SnO2 did not improve the efficiency of atrazine removal in Na2SO4, but in NaCl a small increase was observed. Overall there appears to be no great advantage in using SnO2-containing electrodes over the Ti/Ru0.3Ti0.7O2 electrode.