Investigation of the effect of supporting electrolyte type and pH parameters on electrooxidation color removal from Direct Blue 86

Abstract

In this study, color removal and electrical consumption from Direct Blue 86 (DB86) dyestuff, commonly used in the textile industry, were investigated using the electrooxidation method. A jacketed glass reactor with a volume of 2000 mL was preferred for the electrooxidation process. Five anode and five cathode electrodes with dimensions of 70 x 100 mm were used. Ti/IrO2/RuO2 was chosen as the anode material, and stainless steel (plate type) electrodes were preferred as the cathode. The effects of the supporting electrolyte type and pH parameters on color removal were investigated. NaCl, KCl, NaNO3, and Na2SO4 were used as supporting electrolytes. Experiments were conducted at pH 3, 5, 7, 9, and 11 with an applied current density of 0.325 mA/cm2. The results showed that KCl as the supporting electrolyte provided the highest color removal efficiency with 99.76%. The optimum pH value was found to be pH 9. The minimum energy consumption was calculated as 3.39 kW-h/m3 for pH 11. Based on the obtained results, it was concluded that the electrooxidation method is effective in color removal and can be preferred due to its ease of use and process control advantages.