Zhao Zhiyuan, Zhang Jinna, Yao Jie, You Shijie
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
Environ Res. 2022 Jul;210:113004. doi: 10.1016/j.envres.2022.113004. Epub 2022 Feb 23.
Electro-oxidation is a promising technology for removal of refractory organic pollutants. While the appeal of this technology lies in its chemical-free nature, commercially scale-up application may be limited by the availability of electrode materials and mass transport. Here we report the development of a flow-through electro-oxidation system for removal of chlorophenols in water using Magnéli-phase (TiO) tubular anode and a 304 stainless steel (SS) tubular cathode. The key to this system was the porous and conductive Magnéli-phase TiO anode, the structure and composition of which was confirmed by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. System efficacy was evaluated by using 4-chlorophenol (4-CP) as a typical refractory contaminant and model chlorophenol. Under optimized conditions, a complete removal of 4-CP could be obtained within 120 min in 0.04 mol L NaSO solution. Electro-produced HO and direct electron transfer were both shown to contribute to the 4-CP electro-oxidation process due to the high selectivity and oxygen evolution potential of the TiO anode. The intermediates of 4-CP degradation were identified and a pathway for its electro-oxidation was proposed. When challenged with industrial wastewater containing 4-CP, chemical oxygen demand (COD) and total organic carbon removal efficiencies of 67.5% and 63.1% respectively could be obtained, accounting for energy consumption of 85.1 kWh·kg COD for degradation of 1 kg of COD in industrial wastewater. This study provides an effective and robust solution for the removal of refractory emerging contaminants from industrial wastewaters using a continuous-flow electro-oxidation system.
电氧化是一种去除难降解有机污染物的很有前景的技术。虽然这项技术的吸引力在于其无化学物质的特性，但商业规模的扩大应用可能会受到电极材料可用性和传质的限制。在此，我们报告了一种流通式电氧化系统的开发，该系统使用马格涅利相（TiO）管状阳极和304不锈钢（SS）管状阴极来去除水中的氯酚。该系统的关键在于多孔且导电的马格涅利相TiO阳极，其结构和组成通过扫描电子显微镜、X射线衍射和X射线光电子能谱得以确认。通过使用4-氯酚（4-CP）作为典型的难降解污染物和模型氯酚来评估系统的效能。在优化条件下，在0.04 mol L NaSO溶液中，120分钟内可实现4-CP的完全去除。由于TiO阳极具有高选择性和析氧电位，电生成的HO和直接电子转移都被证明有助于4-CP的电氧化过程。确定了4-CP降解的中间产物，并提出了其电氧化途径。当处理含有4-CP的工业废水时，化学需氧量（COD）和总有机碳的去除效率分别可达67.5%和63.1%，降解1 kg工业废水中的COD能耗为85.1 kWh·kg COD。本研究提供了一种有效且可靠的解决方案，用于使用连续流电氧化系统从工业废水中去除难降解的新兴污染物。
