A Sustainable Aluminium-Based Electro-Fenton Process for Pharmaceutical Wastewater Treatment: Optimization, Kinetics, and Cost–Benefit Analysis

Pharmaceutical contamination poses growing environmental risks, yet industrial adoption of advanced oxidation processes (AOPs) remains limited by high costs and the environmental impacts associated with specialized electrodes. This study demonstrates that unmodified aluminum electrodes achieve pharmaceutical degradation performance comparable to precious metal systems at dramatically reduced cost and carbon footprint. An aluminum-based electro-Fenton (EF) system was optimized for amlodipine (AML) removal through systematic evaluation of operational parameters. Under optimized conditions (pH 2.7, 35 mg L−1 FeCl3, 1.3 mM NaCl, 5 V), the system achieved 97% AML degradation within 15 min, following pseudo-first-order kinetics (k=0.15 min−1). The mechanism combines hydroxyl radical oxidation with synergistic electrocoagulation resulting from anodic Al3+ release and cathodic Fe2+ regeneration. Sustainability assessment revealed exceptional performance: an energy consumption of 0.32 kWh m−3, a carbon footprint of 0.53 kg CO2-eq m−3 (60–75% lower than conventional AOPs), and operational costs of $0.71–1.05 m−3. Aluminum electrodes cost 100× less than platinum alternatives, with the generated Al(OH)3 sludge offering valorization potential. This work demonstrates that high-performance electrochemical remediation is achievable using Earth-abundant materials, providing a scalable and cost-effective alternative for pharmaceutical wastewater treatment in resource-constrained settings.