Electro-Fenton treatment of antibiotics in aqueous matrices. A review of recent development in the period 2022-2025

Antibiotics are prescribed to humans and animals to fight and heal bacteriological diseases. Their accumulation in natural waters and real wastewaters can enhance the resistance to bacterial infection with damage of beneficial bacteria. This work presents a comprehensive and didactic review on the most relevant research of the homogeneous and heterogeneous electro-Fenton (EF) treatments of antibiotics in aqueous matrices, covering the period 2022-2025. The fundamentals and characteristics of each kind of EF process are separately detailed, explaining the generation of oxidizing agents such as • OH, O 2 • − , and 1 O 2 , sulfate radical, and HClO. The application of homogeneous EF, homogeneous EF-like, and heterogeneous EF with solid catalysts or functionalized cathodes to the fast and (almost) total degradation and/or slower mineralization of antibiotics is subsequently analyzed. Stirred undivided tank reactors and flow reactors with two- or three-electrodes filled with synthetic solutions were considered, with didactic attention to the role of generated oxidants, operating variables, by-products formed, reaction sequences proposed, and reusability of the electrolytic systems. A continuous flow-through reactor with functionalized carbon/N-CNTs/FeNi cathode maintained total degradation with 78%TOC reduction of 117 mg L −1 florfenicol during 72 h. The behavior of several real wastewaters was examined as well. The changes of toxicity of treated antibiotic effluents are detailed using bioindicators or theoretical predictions of by-products formed with ECOSAR and T.E.S.T. programs. Challenges and future perspectives of EF techniques over antibiotics removal are finally discussed.