Electrochemical advanced oxidation processes (EAOPs) are increasingly recognized as energy-efficient and sustainable solutions for the treatment of industrial and municipal wastewater, particularly for the removal of recalcitrant organic pollutants that are often resistant to conventional treatment methods. Among these, Galvano-Fenton systems, which exploit the spontaneous corrosion of iron coupled with cathodic catalysis, offer the unique advantage of combining pollutant degradation with in situ electrical energy generation, thereby eliminating the need for external power sources and contributing to more sustainable operation. In this study, a Galvano-Fenton system based on a galvanic Fe/Cu electrode configuration was systematically investigated to evaluate both its environmental and energetic performance under controlled laboratory conditions. The system enables continuous production of ferrous ions and highly reactive hydroxyl radicals, facilitating efficient degradation of organic contaminants under mild operating conditions while minimizing chemical consumption.

Special attention was paid to electrode design and configuration. The effects of increasing cathode surface area relative to the anode, electrode material selection, and cathode-to-anode surface area ratios (ranging from 1:1 to 6:1) were examined in detail. Key operating parameters, including solution pH (2–3), hydrogen peroxide concentration (3 mM), and reaction time (up to 60 minutes), were optimized in terms of pollutant removal efficiency, reaction kinetics, and electrical power output. Results demonstrated that enlarging the cathode surface significantly enhances electrical energy generation, achieving power densities of up to 220 mW·m⁻², currents of 1.5–2 mA, and potentials reaching 0.85 V. Simultaneously, malachite green degradation efficiencies were maintained at very high levels (98–100%), highlighting the system’s excellent catalytic performance, operational stability, and potential for scale-up.

Overall, this work demonstrates the dual environmental and energetic functionality of the Galvano-Fenton process. The findings underscore the critical role of electrode configuration in maximizing energy recovery while maintaining high pollutant degradation efficiency. The study provides valuable insights for the rational design of sustainable electrochemical wastewater treatment technologies, bridging the gap between laboratory-scale research and potential real-world applications in energy-positive and resource-efficient wastewater management.