ANODIC DEGRADATION OF CAFFEINE UNDER DIFFERENT OPERATING CONDITIONS

This study investigates the electrochemical oxidation of caffeine under various operating parameters (current density, initial caffeine concentration, electrode material (BDD, PbO2, and Pt), and sample matrix). According to cyclic voltammetric analysis, the oxidation of caffeine on BDD was found to be electrochemically irreversible. The degradation efficiency of caffeine increased with increasing current density but noticeably decreased as initial caffeine concentration increased. Superior to the PbO2 and Pt electrodes for caffeine degradation and total organic carbon abatement, the BDD anode exhibited the highest maximum value of caffeine mineralization current efficiency. At 200 mA/cm(2) and 25 degrees C, the pseudo-first-order rate constants of caffeine oxidation were 7.6 x10(-4) and 6.9x10(-4) 1/s in 0.1 M Na2SO4 solution and secondary (municipal) wastewater treatment plant effluent, respectively.