Electrochemical Advanced Oxidation Processes for Real Wastewater Remediation: Systems, Performance, and Generated Oxidants
Enric Brillas, Sergi Garcia‐Segura
Abstract
High Resolution Image Download MS PowerPoint Slide Real wastewaters contain complex mixtures of suspended solids, pathogens, nutrients, and organic and inorganic compounds. These hazardous constituents originate eco-toxicological effects and human health problems when released into the environment. This Review presents a comprehensive critical assessment of the application of electrochemical advanced oxidation processes to the remediation of real wastewaters in the period of 2020–2024. First, anodic oxidation (AO) is described, showing the capacity to remove up to 93% of chemical oxygen demand when using boron-doped diamond (BDD) and PbO 2 anodes. More rapid organic degradation in real waters and up to 97% mineralization were further reported for the homogeneous electro-Fenton (EF) process with BDD and Fe 2+ . Lower mineralization efficiency was reported for heterogeneous EF with functionalized iron cathodes and solid iron catalysts and the heterogeneous EF-like reaction with non-ferrous materials. The photoelectro-Fenton (PEF) process with UVA light more quickly yielded up to 98% mineralization through the rapid photodecarboxylation of final Fe(III)-carboxylate complexes. Hybrid and sequential AO, EF, and PEF processes are described. The systems used, the performance as a function of operating variables, the generation of oxidants (active chlorine, ClO •, • OH, O 2 •–, and/or 1 O 2 ), reusability, and by-products produced are discussed. Finally, the loss of toxicity of treated real wastewaters is described, and the total treatment cost and techno-economic studies published are analyzed.