A Comparative Study of Sequential Electrocoagulation (EC) With Fenton and Electro‐Fenton (EF) Process for the Treatment of Real Pharmaceutical Wastewater

ABSTRACT Pharmaceutical wastewater is characterized by complex and recalcitrant organic compounds that pose serious environmental and ecological risks. The current study investigates the effectiveness of a novel sequential process integrating electrocoagulation (EC) with Fenton (F) and electro‐Fenton (EF) oxidation for the treatment of real pharmaceutical effluent, with performance evaluated in terms of chemical oxygen demand (COD) removal. The EC process was optimized by adjusting current density (up to 200 mA), pH, and external coagulant dosage, achieving a maximum COD removal of 42%. The addition of external chemical coagulants, such as polyaluminum chloride (PAC), alum, ferric chloride, and aluminum chloride improved pollutant removal efficiency compared to the electrochemical process alone. Under acidic conditions (pH = 3), the EF process using hydrogen peroxide (250–1000 mg/L) and ferrous sulfate (30–120 mg/L) achieved a maximum COD reduction of 65%, while the conventional Fenton process resulted in 45% removal. Sequential coupling of EC and EF under optimized conditions yielded a COD removal of 85%, and the combination of EC followed by PAC and EF achieved the highest COD reduction of 92%. The results clearly demonstrate the synergistic effect of the EC–PAC–EF process in degrading refractory organic pollutants from pharmaceutical wastewater and hence highlight the potential of hybrid electrochemical treatment as an efficient and sustainable solution.