Towards industrial implementation of Electro-Fenton and derived technologies for wastewater treatment: A review

This is an updated critical review of the advances towards the full exploitation of diverse Electro-Fenton technologies for the decontamination of real effluents at industrial scale. The main relevant innovations spanning almost three decades are analyzed from a historical perspective. Electro-Fenton, Photoelectro-Fenton, Peroxi-coagulation, Sonoelectro-Fenton and related methods are assessed. Economic aspects and engineering challenges that should be overcome to reach the title goal, such as efficient cathodes for H2O2 electrogeneration, heterogeneous catalysis, the pH issue, and the iron sludge problem are particularly highlighted. A special section is devoted to examining the R&D works on actual wastewaters. Overviews of both pilot scale studies currently available in the literature and companies that already provide some of these technologies are presented. Finally, suggestions for further development at a large scale, depending on wastewater characteristics, are summarized.