Study to Carry out the Degradation of Industrial Dyes Applying Electrochemical/BDD Process in a Laboratory Stirred Tank Reactor

Abstract

Degradation of the real industrial dyes Blue BR, Violet SBL and Brown MF 50 mgL-1 has been studied by the electrochemical oxidation (EOx), electro-Fenton (EF), photoelectro-Fenton (PEF) process based on BDD electrode. Each dye was tested in 0.05 mM Na2SO4 with 0.5 mM Fe2+ at pH 3.0, and electrolyzed in a stirred tank reactor under galvanostatic conditions with 2.0, 5.0, 7.0, 11.0 and 18.0 mAcm-2. Dyes were oxidized via hydroxyl radicals (·OH) formed at the BDD anode from water oxidation coupled with Fenton’s reaction cathodically produced hydrogen peroxide (H2O2). Under Na2SO4 medium close to 100% the decolorization was achieved. Through the color abatement rate the dyes behavior was analyzed at the beginning of the oxidation process. Dissolved Organic Carbon (DOC) was tested to evaluate the degradation. From DOC removal, it was established an increasing relative oxidation power of the PEF>80%, according with their decolorization trend. This study highlights the potential of the electrochemical/BDD process for the degradation of industrial dyes found in wastewaters under appropriate experimental conditions.