Electrochemical oxidation of phenolic compounds using a flow-through electrolyser with porous solid electrodes

Organic compounds such as phenol and cresols may be found in industrial wastewater along with other organics and are difficult to be economically removed down to concentrations below environmentally permissible limits. By circulating a wastewater through an electrolytic reactor with a stack of porous solid anodes and cathodes, it has been demonstrated that it is feasible to electrochemically oxidize phenolic compounds in the presence of other organic molecules. A porous solid DSA(R)-type titanium anode coated with several mixed oxide layers was used as the active material. At low applied current densities, phenol and cresol concentrations were reduced from 5000 ppb to below 20 ppb. The influence of the flow rate and electrodes number was also studied and it was demonstrated that the current density was the main factor to be considered. This work confirms the hypotheses of other authors on the reaction mechanisms involved during the electrochemical oxidation of cresol and phenol.