Removal of phenolic compounds by electro-assisted advanced process for wastewater purification

Electro-assisted advanced process was developed for wastewater treatment of phenolic compounds. A series of correlative experiments were carried out: the degradation of phenol by the advanced electrochemical oxidation process, the degradation of chlorophenol by the photo-electrocatalysis, and the degradation of chlorophenol by pair electrodes. It was found that phenol and chlorophenol could be removed rapidly and effectively at initial concentration of 100-400 mg L-1, current density of 3.2-27.5 mA cm(-2), and applied voltage of 2-5 V. The combination of electrocatalytic and UV radiation greatly accelerated the removal efficiency. The dechlorination of chlorophenol could be achieved under cathodic reduction so that it could be further oxidized more quickly and completely. The mechanism of dechlorination was proposed to be the indirect dechlorination by atomic hydrogen. The electro-assisted advanced processes were suitable for the treatment of the phenolic compounds.