Indirect Electrochemical Oxidation of Reactive Blue 19 Dye as a Model Organic Substrate: Role of Anode Material and Oxidants Electrochemically Generated

The indirect electrochemical oxidation (IEO) of Reactive Blue 19 has been studied at boron-doped diamond (BDD) and Ru0.3Ti0.7O2/Ti anodes by applying 25, 50 and 75 mA cm(-2) in presence of NaCl as supporting electrolyte. Results clearly showed that electrochemical degradation of dye was achieved via electrogenerated species (hydroxyl radicals and active chlorine), obtaining higher removal efficiencies of color (100% for both anodes) and organic matter from solution (from 30 up to 60% for Ru0.3Ti0.7O2/Ti and from 65 up to 80% for BDD). In order to understand the key role of oxidants, active chlorine species were also determined, achieving different concentrations of dissolved Cl-2, HClO, ClO-, chlorite, chlorine dioxide and chlorate at both anodes, as a consequence of experimental conditions used as well as the nature of electrode material employed. For BDD, the IEO was more effective due to the effective production of (OH)-O-center dot radicals as well as HClO and ClO- species that favor the degradation of organic matter. The results are discussed on the light of existing literature. (C) 2015 The Electrochemical Society.All rights reserved.