Development of an electrocoagulation method using alternating pulse current to treat wastewater generated by tanneries

Abstract

Direct current electrocoagulation has various drawbacks, including electrode passivation, heat creation from energy consumption, and high sludge formation. The restrictions limit its usage in tannery wastewater treatment. Therefore, alternating pulse current EC (APC-EC) was developed to solve these obstacles. The study was empirically examined, considering high-frequency (3,000–11,000 Hz), stirring speed (400–1,200 rpm), and reaction time (15–30 min). This research examined how factors affect chemical oxygen demand (COD) removal efficiency, turbidity from trivalent chromium (Cr+3), and energy consumption for perforated aluminum electrodes. The central composite design in the surface response design approach has improved various operational parameters in the APC-EC process for tannery wastewater treatment. The employment of mathematical and statistical methods resulted in optimal removal of COD, Cr+3, and turbidity while reducing energy usage. Using mathematical and statistical methods, we achieved maximum COD, Cr+3 ion, and turbidity reduction while reducing energy use. The investigation found that COD (70.3%), Cr+3 (89.56%), and turbidity (96%) were the most rapidly removed components at 11,000 Hz, 576 rpm, and 30 min. Surface response data explain high-frequency APC-EC dynamics.