Effect of air pressure on the electro-Fenton process at carbon felt electrodes. (20th May 2018) - Pérez, J.F.
Abstract: The effect of air pressure on electro-Fenton (PrEF process) was evaluated using two organic substances (maleic acid and Acid Orange 7) as model organic pollutants. First experiments were performed using a conventional carbon felt (CF) cathode. At room pressure, a slow removal of maleic acid was obtained, together with the generation of formic acid. Conversely, using pressurized air, the removal of maleic acid was dramatically accelerated and the formation of formic acid was not detected. The utilization of a carbon felt modified by the deposition of carbon black + PTFE mixture (MCF) and of pressurized air allowed to achieve even faster and almost total (>95%) removal of total organic carbon (TOC). Interestingly, the abatement resulted higher than the one obtained previously by direct anodic oxidation at boron doped diamond under comparable conditions. Similarly, in the case of Acid Orange 7 (AO7) the removal of the TOC increased with the pressure using both CF and the MCF. In particular, high removal of TOC (close to 80%) was obtained using the MCF at high current density (100 mA cm −2 ) under pressurized air. Highlights: The PrEF process is highly efficient for the removal of dyes and carboxylic acids. It benefits both from higher H2 O2 production and OH -induced oxygen oxidation. The PrEF using MCF cathode is more efficient than anodic oxidation with BDD for the removal of maleic acid.