Electrochemical monitoring of decolorization of diazo dye Evans blue by Fenton process under anaerobic conditions: Kinetics and optimization

Abstract

The decolorization of Evans Blue (EB), a diazo dye, by Fenton process under anaerobic conditions has been investigated using cyclic voltammetry technique. Effects of solution pH, concentrations of H<inf>2</inf>O<inf>2</inf>, Fe2+ and EB on the decolorization of EB have also been studied. About 98.9% decolorization was found under the optimal conditions [EB]: [Fe2+]: [H<inf>2</inf>O<inf>2</inf>] = 1: 1.9: 4.7 and [H<inf>2</inf>O<inf>2</inf>]/[Fe2+] = 2.5 at pH 2 in 403 seconds. The kinetic data at pH 2 revealed that Behnajady–Modirshahla–Ghanbery (BMG) model was more favorable to describe the decolorization of EB than the zero-, first- and second-order kinetic models. Our experimental results will provide a fundamental knowledge for the more effective treatment of EB in a short time by Fenton’s reagent. © 2015, Pleiades Publishing, Ltd.