Effect of the pressure on the cathodic production of H2O2 and on electro-Fenton in undivided and divided cells

The key step for both the electrochemical H2O2 production and the electro-Fenton (EF) process is the cathodic reduction of O2 which is adversely affected by the low oxygen solubility in water contacted at atmospheric pressure of air. In this work, we studied the effect of current density and air pressure on the H2O2 production and on the EF process using both a divided and an undivided cell. It was shown that the use of pressures between 5 and 15 bar allows to enhance drastically the H2O2 production in both undivided and divided cells and that the best results were achieved in the presence of the separator. Moreover, the coupled use of pressurized air and divided cells made it possible to accelerate the organics removal achieved by the EF process. Eventually, the advantages given by the utilization of divided and undivided cells and of pressurized air were analyzed from both technical and economic points of view.