title: Hydroxyl radical generation in electro-Fenton process with a gas-diffusion electrode: Linkages with electro-chemical generation of hydrogen peroxide and iron redox cycle.
abstract: The hydroxyl radical generation in an electro-Fenton process with a gas-diffusion electrode which is strongly linked with electro-chemical generation of hydrogen peroxide and iron redox cycle was studied. The OH radical generation subsequent to electro-chemical generations of H2O2was examined under the constant potential in the range of Fe2+dosage from 0 to 1.0 mM. The amount of generated OH radical initially increased and gradually decreased after the maximum was reached. The initial rate of OH radical generation increased for the Fe2+dosage <0.25 mM and at higher Fe2+dosages remained constant. At higher Fe2+dosages the precipitation of Fe might inhibit the enhancement of OH radical generation. The experiments for decolorization and total organic carbon (TOC) removal of azo-dye Orange II by the electro-Fenton process were conducted and the quick decolorization and slow TOC removal of Orange II were found. To quantify the linkages of OH radical generation with dynamic behaviors of electro-chemically generated H2O2and iron redox cycle and to investigate effects of OH radical generation on the decolorization and TOC removal of Orange II, novel reaction kinetic models were developed. The proposed models could satisfactory clarify the linkages of OH radical generation with electro-chemically generated H2O2and iron redox cycle and simulate the decolorization and TOC removal of Orange II by the electro-Fenton process.
authors.affiliation: a Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry , Toyo University , Kawagoe, Saitama , Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yatagai
authors.affiliation: a Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry , Toyo University , Kawagoe, Saitama , Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ohkawa
authors.affiliation: a Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry , Toyo University , Kawagoe, Saitama , Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Kubo
authors.affiliation: a Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry , Toyo University , Kawagoe, Saitama , Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kawase
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004058:Diffusion; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron; C014722:2-naphthol orange
keywords: Azo-dye Orange II degradation; electro-Fenton process; gas-diffusion electrode; hydroxyl radical; iron redox cycle