Comparative mineralization of Basic Red 18 with electrochemical advanced oxidation processes

Abstract

In this study, the role of electrochemical oxidation processes, including the electro-Fenton, the electro-persulfate (PS), and the electro/FeII /PS processes, in the removal of Basic Red 18 (BR18) from aqueous solutions was investigated. It was found that the electro-PS process successfully removes colour, but after 5 h, it produced only 75 % mineralization. In the same conditions, more effective mineralization was achieved by the electro/FeII/PS process than by the electro-Fenton method. At pH levels of 3.0 and 5.7, very effective mineralization results were produced by the electro/FeII/PS process. Moreover, the maximum mineralization current efficiency values were obtained by the electro/ FeII/PS process. The mineralization efficiency of the electro/FeII/PS process was determined to be 97 % under the following conditions: BR18 initial dye concentration of 100 mg L-1, pH of 5.7, contact time of 5 h, PS concentration of 10 mM, Fe2+ concentration of 0.2 mM, and a sodium sulfate concentration of 0.05 M.

Keywords

• Advanced electro-oxidation processes
• Fenton
• persulfate
• azo dye
• decolorization