title: Electrochemical oxidation of perfluorinated compounds in water.
abstract: Perfluorinated compounds (PFCs) are persistent and refractory organic pollutants that have been detected in various environmental matrices and municipal wastewater. Electrochemical oxidation (EO) is a promising remediation technique for wastewater contaminated with PFCs. A number of recent studies have demonstrated that the "non-active" anodes, including boron-doped diamond, tin oxide, and lead dioxide, are effective in PFCs elimination in wastewater due to their high oxygen evolution potential. Many researchers have conducted experiments to investigate the optimal conditions (i.e., potential, current density, pH value, plate distance, initial PFCs concentration, electrolyte, and other factors) for PFCs elimination to obtain the maximal elimination efficiency and current efficiency. The EO mechanism and pathways of PFCs have been clearly elucidated, which undergo electron transfer, Kolbe decarboxylation or desulfonation, hydrolysis, and radical reaction. In addition, the safety evaluation and energy consumption evaluation of the EO technology have also been summarized to decrease toxic ion release from electrode and reduce the cost of this technique. Although the ultrasonication and hydrothermal techniques combined with the EO process can improve the removal efficiency and current efficiency significantly, these coupled techniques have not been commercialized and applied in industrial wastewater treatment. Finally, key challenges facing EO technology are listed and the directions for further research are pointed out (such as combination with other techniques, treatment for natural waters contaminated by low levels of PFCs, and reactor design).
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China. Electronic address: junfengn@bnu.edu.cn.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Enxiang
authors.initials: E
authors.lastname: Shang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Zesheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Jinzi
authors.initials: J
authors.lastname: Liu
mesh_terms: D001895:Boron / Q000737:chemistry; D018130:Diamond / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005466:Fluorocarbons / Q000032:analysis*; D007854:Lead / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D001895:Boron; D018130:Diamond; D005466:Fluorocarbons; D007854:Lead; D010087:Oxides; D017971:Tin Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical; C047365:lead oxide; C045358:stannic oxide
keywords: Combination technique; Electrochemical oxidation; Electrochemical oxidation mechanisms; Energy consumption; Perfluorinated compounds; Safety evaluation