Wet electrolytic oxidation of cationic red X-GRL

Abstract

Wet electrolytic oxidation (WEO) under mild condition, a relatively less reported process which coupled the advantages of both wet air oxidation (WAO) and electrochemical oxidation (EO) was investigated for the removal of one azo dye, cationic red X-GRL, in a 2 L autoclave reactor. It was found that this novel process showed synergistic effect for TOC removal compared with that by the individual WAO and EO, and presented much higher dye removal efficiency. At similar conditions of temperature of 100–180 °C, P N 2 = 0.50 MPa and P O 2 = 0.14 MPa , a little introduction of current density of 2 mA cm −2 led to the apparent reaction constants for WEO two times larger than those of WAO. Possible mechanism for the synergistic effect was discussed based on the analysis of free-radical generation and intermediates detected by GC/MS.