Efficient De-colorization of Methylene Blue by Electro-coagulation Method: Comparison of Iron and Aluminum Electrode

In this study, removal of methylene blue by electro-coagulation method using aluminum and iron electrodes was investigated. The influence of the operating parameters such as contact time, current density, anode type, inter-electrodes distance, initial and final pH and energy consumption rate was determined. Dye removal was increased with increases in solution pH, current density and contact time and then decreased for increase in initial dye concentration and electrodes distance. The results show that the electrochemical method has significant efficiency in removal of methylene blue, higher efficiency was observed for iron (Fe) electrode; namely 100% and 95.78% of dye was removed by iron and aluminum electrode; respectively, after 24 min contact time. For a given current density, the removal efficiency and energy consumption rate showed that iron electrode was superior to aluminum in removal of methylene blue. In the case of iron as anode type, the required energy for complete dye decolorization was 3.8 kWh/m3; for 98% dye removal, the required energy was observed to be 4.3kWh/m3 in the case of aluminum as anode type. In general, complete methylene blue can be removed at operating parameters condition of iron as anode, distance between electrodes of 1cm, solution pH of 9 and current density of 50 A/m2 for 24 min electro-coagulation time.