Abstract: Phenol degradation with three electrocatalysis processes; anodic electrocatalysis(AE), anodic-cathodic electrocatalysis (ACE) and ferrous ion catalyzed anodic-cathodic electrocatlysis (FeACE) were compared. At current of 0. 25 A, the removal rate of CODin wastewater is only 30% by using AE, while it is 60% by using ACE, and 90% by using FeACE. The main intermediates during the phenol degradation are hydroquinone, catechol, resorcinol, benzoquinone, maleic acid, fumaric acid and oxalic acid. When FeACE was used, formic acid was also observed and the final product is carbon dioxide. FeACE can increase the removal rate of COD, and benefit the rapid elimination of toxic intermediates as well. Furthermore, the process could reach the mineralization of organic compound, showing much more optimistic potential for the environmental protection. The mechanism of organic degradation was confirmed to be the role of hydroxyl radical by using salicylic acid as the radical trapping, which are more likely to attack benzene ring in the sequence of p^-, m^-, o^-. Adegradation mechanism for phenol was also proposed.

Key words: Anodic-cathodic electrocatalysis, Phenol degradation, Advanced oxidation processes(AOPs), Degradation mechanism