Electrochemical oxidation of phenol using graphite anodes

The effects of current and pH on the electrochemical oxidation of phenol on graphite electrodes is investigated in this study. There was no sign of deterioration of the graphite bed after 5 months of operation. Phenol removal efficiency was a function of the current applied and was around 70% at a current of 2.2 A. The increase of phenol removal efficiency with current is attributed to the increase of ionic transport which increases the rate of electrode reactions responsible for the removal process. The percentage of complete oxidation of phenol increases with current, with a maximum value of about 50%. However, at pH 0.2 it is slightly higher than that at pH 0.5 at all currents. The phenol removal rate increases with increases of current and pH. While the current (CO₂) efficiency reaches a maximum value in the current range of 1.0-1.2 A, it increases with an increase of acid concentration. The findings of this study have important implications: While anodic oxidation of phenol on graphite can achieve acceptable removal of phenol, the extent of oxidation should not be overlooked.