title: Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process.
abstract: Electro-peroxone (E-peroxone) is a novel electrocatalytic ozonation process that combines ozonation and electrolysis process to enhance pollutant degradation during water and wastewater treatment. This enhancement has been mainly attributed to several mechanisms that increase O3 transformation to ·OH in the E-peroxone system, e.g., electro-generation of H2O2 from O2 at a carbon-based cathode and its subsequent peroxone reaction with O3 to ·OH, electro-reduction of O3 to ·OH at the cathode, and O3 decomposition to ·OH at high local pH near the cathode. To get more insight how these mechanisms contribute respectively to the enhancement, this study investigated total organic carbon (TOC) elimination from oxalic acid (OA) solutions by the E-peroxone process. Results show that the E-peroxone process significantly increased TOC elimination rate by 10.2-12.5 times compared with the linear addition of the individual rates of corresponding ozonation and electrolysis process. Kinetic analyses reveal that the electrochemically-driven peroxone reaction is the most important mechanism for the enhanced TOC elimination rate, while the other mechanisms contribute minor to the enhancement by a factor of 1.6-2.5. The results indicate that proper selection of electrodes that can effectively produce H2O2 at the cathode is critical to maximize TOC elimination in the E-peroxone process.
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Huijiao
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Yuan
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China; Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650500, China.
authors.forename: Juhong
authors.initials: J
authors.lastname: Zhan
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China. Electronic address: wangyujue@tsinghua.edu.cn.
authors.forename: Yujue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
mesh_terms: D002244:Carbon / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D004566:Electrodes; D004572:Electrolysis / Q000295:instrumentation / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D019815:Oxalic Acid / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D006878:Hydroxides; D012996:Solutions; D014874:Water Pollutants, Chemical; D010126:Ozone; D002244:Carbon; C031356:hydroxide ion; D019815:Oxalic Acid; D006861:Hydrogen Peroxide; D010100:Oxygen
keywords: Advanced oxidation; Electrocatalytic ozonation; Electrolysis; Hydrogen peroxide; Ozone