Niu Junfeng, Li Yang, Shang Enxiang, Xu Zesheng, Liu Jinzi
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
Chemosphere. 2016 Mar;146:526-38. doi: 10.1016/j.chemosphere.2015.11.115. Epub 2015 Dec 30.
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).
全氟化合物（PFCs）是持久性难降解有机污染物，已在各种环境基质和城市废水中被检测到。电化学氧化（EO）是一种有前景的用于处理受PFCs污染废水的修复技术。最近的一些研究表明，包括硼掺杂金刚石、氧化锡和二氧化铅在内的“非活性”阳极，因其高析氧电位，在去除废水中的PFCs方面是有效的。许多研究人员进行了实验，以研究去除PFCs的最佳条件（即电位、电流密度、pH值、极板间距、初始PFCs浓度、电解质和其他因素），以获得最大去除效率和电流效率。PFCs的EO机理和途径已得到明确阐释，其过程包括电子转移、科尔伯脱羧或脱磺、水解和自由基反应。此外，还总结了EO技术的安全性评估和能耗评估，以减少电极释放有毒离子并降低该技术的成本。尽管超声和水热技术与EO工艺相结合可显著提高去除效率和电流效率，但这些耦合技术尚未商业化并应用于工业废水处理。最后，列出了EO技术面临的关键挑战，并指出了进一步研究的方向（如与其他技术结合、处理受低水平PFCs污染的天然水以及反应器设计）。
