Electrochemical removal of rhodamine 6G by using RuO2 coated Ti DSA

Abstract

In this study, electrochemical removal of rhodamine 6G containing wastewater using RuO2-coated Ti mesh as dimensionally stable anode is investigated. The effects of pH, supporting electrolyte, electrolyte concentration, applied current, and distance between electrodes on the removal efficiency were examined in a batch reactor. It is shown that NaCl is the best supporting electrolyte among NaCl, Na2SO4, NaClO 4, and NaNO3. Lower solution pH and higher concentration of supporting electrolyte facilitate the treatment process. Small distance between electrodes greatly decreases the energy consumption. The decolorization efficiency of above 99.5% and the low energy consumption of 1.58 kWh/m 3 can be achieved under the optimized experimental condition of NaCl concentration of 0.2 M, applied current of 1.0-1.9 A, pH < 6, and distance between electrode of 5 mm. The RuO2-coated Ti mesh anode is shown to have good recyclability and lifespan. A greater dye removal of 99.2% can be obtained by a continuous stirred-tank reactor with a HRT of 4 min. It is anticipated that the developed technology from this study can be further scaled up for full-scale treatment of industrial dye containing wastewater. © 2009 American Chemical Society.