Decolorization of Synthetic Azo Dyes by Electrochemically Generated •OH Radicals in Acidic Medium using Boron Doped Diamond (BDD) Electrodes

Abstract

In this work, a comparative study of electrochemical degradation of Acidic yellow 36 (Ay-36) and Methyl orange (MO) aqueous solutions using direct electrochemical oxidation (DEO) and electro-Fenton system (EF) processes are reported. For both processes, Boron Doped Diamond (BDD) electrodes were used as anode and cathode. The electrochemical decolorization of azo dye compounds was followed by UV-Vis spectrophotometry. Decolorization kinetics of the azo dyes by electrochemically generated hydroxyl radicals followed a pseudo-first order model. The DEO-EF combined process generally resulted in higher oxidation rate than DEO process during the first minutes of electrolysis, due to the oxidizing power of H2O2 was enhanced in the presence of Fe2+ via Fenton's reaction.