Combined electrooxidation and assisted electrochemical coagulation of aqueous phenol wastes

The electrochemical treatment of basic (pH 12) aqueous phenol wastes using stainless steel electrodes is described. Two different processes have been identified in the removal of the phenol from aqueous wastes: electrooxidation, which leads to the formation of carboxylic acids and carbon dioxide, and solids-forming assisted electrochemical processes (including complexation, precipitation and/or coagulation) produced by the generation of Fe3+ ions in the waste during treatment. The effect of the initial carbon concentration, temperature and current density has also been investigated. It was determined that increases in the initial carbon concentration and temperature lead to increases in the reaction rates of the treatment processes and that increased current density leads to a decrease in the rate of electrooxidation and an increase in the rate of the solid-forming processes.