Treatment of a Mixture of Chloromethoxyphenols in Hypochlorite Medium by Electrochemical AOPs as an Alternative for the Remediation of Pulp and Paper Mill Process Waters

Here, 100 mg L −1 of dissolved organic carbon of aromatics including chloromethoxyphenols were prepared by exposition of a mixture of guaiacol, syringol, and vanillin in 200 mM NaClO at pH 3.0 and 25 °C for 14 h and further degraded by electrochemical advanced oxidation processes (EAOPs) like anodic oxidation with electrogenerated H 2 O 2 (AO-H 2 O 2 ), electro-Fenton (EF), and photoelectro-Fenton (PEF). Electrolyses were performed with a cell containing either a Pt or boron-doped diamond (BDD) anode and an air-diffusion cathode at constant current density. Oxidants were hydroxyl radicals ( • OH) formed at the anode surface from water oxidation and in the bulk from Fenton’s reaction between added Fe 2+ and H 2 O 2 generated at the cathode, as well as active chlorine species produced from the anodic oxidation of HClO. Oxychlorine ions like ClO 3 − using Pt and ClO 3 − + ClO 4 − using BDD were detected in the electrolyzed solutions. A poor mineralization was found using the Pt/air-diffusion cell, with increasing relative oxidation ability in the sequence AO-H 2 O 2