Electrochemically-driven dosing of iron (II) for autonomous electro-Fenton processes with in situ generation of H2O2

Reliance of Fenton processes to hazardous chemicals diminishes the range of niche applications of this highly efficient advanced oxidation process due to risks associated to transport, storage, and handling of chemicals. In this work, an alternative approach towards independent Fenton systems integrating (1) per demand in situ production of H2O2 from oxygen cathodic reduction and (2) electrochemically-driven iron (II) dosing system is explored as a novel strategy. For this purpose, a dual-cell system was designed to fulfill individual current needs of both processes while avoiding excessive iron sludge production observed in peroxicoagulation treatments. Experimental results indicate high reproducibility and resilience of the proposed dual-cell electro-Fenton system, which attained complete organic methylene blue dye decolorization in 80 min of treatment and over 80% mineralization in only 120 min of electro-Fenton treatment. These results showcase a new approach that opens alternative pathways for possible implementation of low-physical footprint electro-Fenton systems as point-of-entry treatments or even to treat effluents of small and mid-sized industries.