Electrochemical Treatment of Dye Bearing Effluent with Different Anode–Cathode Combinations: Mechanistic Study and Sludge Analysis

Abstract

The present study investigates the electrochemical (EC) treatment of actual dye bearing effluent (DBE) with different combinations of aluminum (Al) and stainless steel (SS) electrodes as anode and cathode. Effects of the current density (<i>j</i>) and pH with different anode–cathode combinations (Al–Al, Al–SS, SS–SS, and SS–Al) were studied. The change in zeta (ζ) potential with current density at different times, and the change in colloid particle diameters at different pH, gave information regarding the potential stability of the colloidal suspension. In addition, specific energy consumption and current efficiency have also been calculated. Maximum color, COD, TOC, and turbidity removal efficiencies were found to be 99.90%, 82.50%, 68.8%, and 98.8%, respectively, at <i>j</i> = 117.64 A/m² and pH 8.5 with the SS–SS electrode combination. Solid residue obtained during EC treatment of DBE was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, and pore distribution analysis to propose reutilization of the sludge