Kinetics and Efficiency Analysis of Electrochemical Oxidation of Phenol: Influence of Anode Materials and Operational Conditions

The influence of operational parameters and anode materials on degradation kinetics, mineralization current efficiency, and energy consumption for electrochemical oxidation of phenol was studied. Phenol elimination follows pseudo-first-order kinetics in most cases except for the Ti/RuO2 anode with a phenol concentration of 500 mg L-1 where pseudo-zero-order kinetics is observed. The total organic carbon removal by a Ti/Sb-SnO2 anode follows pseudo-first-order kinetics in contrast to pseudo-zero-order kinetics by Pt and Ti/RuO2 anodes. For a certain anode, a higher current or voltage input results in a higher reaction rate. With a Ti/Sb-SnO2 anode, the highest current efficiency and the lowest energy consumption are obtained, but the current efficiency decreases (increases for energy consumption) quickly as the reaction is prolonged due to the reduction of organics.