Effect of air pressure on the electro-generation of H2O2 and the abatement of organic pollutants in water by electro-Fenton process

The electro-generation of H2O2 and the abatement of the model organic pollutant Acid Orange 7 (AO7) in water by an electro-Fenton process were perfomed under moderate air pressures (up to 11 bar) for the first time. An increase of the pressure gave rise to a drastic enhancement of the concentration of hydrogen peroxide. At 11 bar, the reduction of oxygen gave rise at a graphite cathode to a concentration of H2O2 of about 12 mM, about one order of magnitude higher than that achieved at atmospheric pressure, as a result of mass transport intensification. Similarly, for electro-Fenton, a drastic increase of the abatement of TOC was achieved upon increasing the air pressure. The effect of the current density was also investigated in detail.