Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6365544 | Water Research | 2016 | 12 Pages |
â¢ClO4â formation can be prevented by using Pt/Ti anodes in the E-peroxone process.â¢E-peroxone process with Pt/Ti anodes can achieve comparable pollutant degradation rates as with BDD anodes.â¢ClO4â is primarily generated at the surface of BDD anode in the E-peroxone process.â¢Electro-generation of H2O2 from O2 at carbon-based cathodes can decrease ClO4â formation.
This study investigated the degradation of clofibric acid and formation of perchlorate during the electro-peroxone (E-peroxone) treatment of chloride-containing (26.1-100 mg Lâ1) water (Na2SO4 electrolytes and secondary effluents). The E-peroxone process involves sparging O2 and O3 gas mixture into an electrolysis reactor where a carbon-based cathode is used to electrochemically convert the sparged O2 to H2O2. The electro-generated H2O2 then reacts with sparged O3 to produce OH, which can rapidly oxidize pollutants in the bulk solution. When boron-doped diamond (BDD) electrodes were used as the anode, perchlorate concentrations increased significantly from undetectable levels to â¼15-174 mg Lâ1 in the different water samples as the applied current density was increased from 4 to 32 mA cmâ2. In contrast, no ClO4â was detected when Pt/Ti anodes were used in the E-peroxone process operated under similar reaction conditions. In addition, when sufficient O3 was sparged to maximize OH production from its peroxone reaction with electro-generated H2O2, the E-peroxone process with Pt/Ti anodes achieved comparable clofibric acid degradation and total organic carbon (TOC) removal yields as that with BDD anodes, but did not generate detectable ClO4â. These results indicate that by optimizing operational parameters and using Pt/Ti anodes, the E-peroxone process can achieve the goal of both fast pollutant degradation and ClO4â prevention during the treatment of chloride-containing wastewater.
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