Effective degradation of methylene blue by a novel electrochemically driven process

A new electrochemically driven process (E-peroxone) was developed to treat methylene blue (MB) waste-water. During the E-peroxone process, ozone generator effluent (O-2 and O-3 gas mixture) is continuously sparged into a reactor that has a carbon-polytetrafluorethylene (carbon-PTFE) cathode, which can electrochemically convert the sparged O-2 to H2O2 effectively. The in situ generated H2O2 then reacts with the sparged O-3 to produce hydroxyl radicals (center dot OH), which are a much stronger oxidant than O-3. Thus, by utilizing the sparged O-2 that has little value in ozonation processes to produce H2O2 in situ, the E-peroxone process can achieve the synergy of O-3 and H2O2 (peroxone) on pollutant degradation. The E-peroxone process therefore mineralized MB much more effectively than ozonation. The total organic carbon removal was 93 and 22% after 2 h of the E-peroxone and ozonation treatment, respectively. The E-peroxone process may thus offer a simple and effective method to degrade ozone-refractory organic pollutants in wastewater. (c) 2013 Elsevier B.V. All rights reserved.