Electro-Fenton Process for the Treatment of Dyes in Wastewater

Abstract

This study focuses on the application of electro-Fenton process for the treatment of dyes in wastewater. In this treatment a simple undivided electrochemical system with graphite electrodes was used for the degradation study of three dyes. The e ect of key parameters like pH, current density, electrode material, dyes concentration, Fe2+ and Na2SO4 concentration was rst investigated for Acid Red 97 (AR 97). With these optimum conditions, determined with AR 97, EF process was carried out with Acid Yellow 145(AY 145) and Reactive Black 5(RB 5) in batch mode. About 96 % colour and 66 % COD reduction takes place for 25 ppm AR 97 with a residence time of 180 mins at 2.0 pH, with 0.25 mM Fe2+ and 0.05 M Na2SO4 at a current density of 8.34 mA/cm2. In case of RB 5, the above conditions were not su cient for 25 ppm concentration, around 98 % colour removal take place at a current density of 66.67 mA/cm2 with same residence time and same concentration. EF process not seems to be e ective for concentration more than 25 ppm in this case. For RY 145, EF process seems to be much effective, around 82.23 % colour and 75% COD removal take place for 100 ppm concentration with same residence time and parameters as determined for AR 97.