C.I. Reactive Black 5 degradation by advanced electrochemical oxidation process, AEOP

Abstract

In the last decades, an increasing number of procedures to remove pollutants from wastewater have been reported. Advanced oxidation processes (AOPs) are one of those technologies used for this purpose, namely, for textile wastewater treatment. AOPs are environmentally friendly methods based on chemical, photochemical or photocatalytical production of hydroxyl radical (HO•). This strong oxidant can react with most organic compounds present in wastewater, as dyestuffs. In this paper, an Advanced Electrochemical Oxidation Process (AEOP) is discussed concerning the electrochemical degradation of a vinylsulphone reactive dye, C.I. Reactive Black 5, in the presence of hydrogen peroxide and copper ions. The reaction between H2O2 and electrochemically generated Cu+ ions leads to the production of hydroxyl radicals, causing dye oxidation and degradation. The efficiency of the process is followed by evaluation of dyebath decolorization (measured by color removal), Chemical Oxygen Demand (COD) variation, among other parameters. Simulated dyebath were prepared and diluted to 5 and 20% of initial concentration. Experimental results confirmed the effectiveness of the procedure in C.I. Reactive Black 5 degradation.