Wang Kaixuan, Zhao Kun, Qin Xin, Chen Shuo, Yu Hongtao, Quan Xie
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
J Hazard Mater. 2022 Feb 15;424(Pt D):127747. doi: 10.1016/j.jhazmat.2021.127747. Epub 2021 Nov 19.
Electrochemical anodic oxidation (AO) is a promising technology for wastewater treatment due to its strong oxidation property and environmental compatibility. However, it suffers from high energy consumption for pollutants removal due to the side-reactions of hydrogen evolution reaction on cathode and oxygen evolution reaction on anode. Combining electro-Fenton (EF) with AO not only generated •OH for pollutants degradation but also increased current efficiency. This work investigated a synergic electrocatalysis process between EF and AO with Ti self-doped TiO nanotube arrays (Ti/TNTAs) electrode as both cathode and anode for wastewater treatment. The pseudo-first-order kinetic rate constant of phenol degradation by EF+AO (0.107 min) was 9.7 or 6.3 times as much as that of only EF (0.011 min) or AO (0.017 min) process, respectively. Enhanced pollutants removal of EF+AO could be attributed to the coexistence of •OH oxidation and direct oxidation on Ti/TNTAs surface. The COD of secondary effluent of coking wastewater decreased from 159.3 mg L to 47.0 mg L by EF+AO within 120 min with low specific energy consumption (9.5 kWh kg COD). This work provided a new insight into design of the energy-efficient synergic electrocatalysis process for refractory pollutants degradation.
电化学阳极氧化（AO）因其强大的氧化性能和环境兼容性，是一种很有前景的废水处理技术。然而，由于阴极析氢反应和阳极析氧反应的副反应，其去除污染物的能耗较高。将电芬顿（EF）与AO相结合，不仅能产生用于降解污染物的•OH，还能提高电流效率。本研究以Ti自掺杂TiO纳米管阵列（Ti/TNTAs）电极作为阴极和阳极，研究了EF与AO之间的协同电催化过程用于废水处理。EF+AO降解苯酚的准一级动力学速率常数（0.107 min⁻¹）分别是单独EF（0.011 min⁻¹）或AO（0.017 min⁻¹）过程的9.7倍或6.3倍。EF+AO对污染物去除的增强作用可归因于•OH氧化和Ti/TNTAs表面直接氧化的共存。在120分钟内，EF+AO可将焦化废水二级出水的化学需氧量（COD）从159.3 mg/L降至47.0 mg/L，且比能耗较低（9.5 kWh/kg COD）。本研究为设计高效节能的协同电催化过程降解难降解污染物提供了新的见解。
