School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, China.
J Hazard Mater. 2023 Jun 15;452:131267. doi: 10.1016/j.jhazmat.2023.131267. Epub 2023 Mar 22.
In wastewater treatment by persulfate-based advanced oxidation processes (PS-AOPs), electron-deficient aromatic pollutants (EDAPs) are refractory to nonradical pathway. To explore an efficient degradation pathway for EDAPs, MgCu-biochar (BC) (x = 0.5, 1, 1.5) activated peroxydisulfate (PDS) was developed, which could trigger reductive species (•H) to reduce EDAPs first, and subsequently facilitate electron-transfer degradation of reduced intermediates. The roles of Mg-doping in MgCu-BC to promote PDS activation and 2,4-dibromophenol (DBP) degradation were investigated. The mechanisms were then explored via electron paramagnetic resonance (EPR), chemical probes and Density Functional Theory (DFT) calculations. The results showed that Mg-doping improved metal-support interactions (MSIs) of MgCu-BC, inducing •H formation via electron transfer from Cu atoms during PDS activation, which was thermodynamically favorable. The degradation rate of DBP (k, 0.0494 min) and Br release (5.35 mg L) in MgCu-BC systems were more 31 and 33 times than that in Cu-BC/PDS system, respectively. The degradation mechanism of •H-enhanced electron transfer processes was that •H attacked one Br group of DBP, and then debrominated intermediates were mineralized by electron transfer processes in the MgCu-BC/PDS system. Overall, this study reports a novel pathway in PS-AOPs for selective degradation of EDAPs in wastewaters.
在基于过硫酸盐的高级氧化工艺（PS-AOPs）处理废水中，缺电子芳香族污染物（EDAPs）对非自由基途径具有抗降解性。为了探索 EDAPs 的有效降解途径，开发了 MgCu-生物炭（BC）（x=0.5、1、1.5）激活过二硫酸盐（PDS），它可以引发还原物种（•H）首先还原 EDAPs，然后促进还原中间产物的电子转移降解。研究了 Mg 掺杂在 MgCu-BC 中促进 PDS 活化和 2,4-二溴苯酚（DBP）降解的作用。然后通过电子顺磁共振（EPR）、化学探针和密度泛函理论（DFT）计算来探讨这些机制。结果表明，Mg 掺杂改善了 MgCu-BC 的金属-载体相互作用（MSIs），通过 PDS 活化过程中 Cu 原子的电子转移诱导•H 的形成，这在热力学上是有利的。在 MgCu-BC 体系中，DBP 的降解速率（k，0.0494 min）和 Br 释放（5.35 mg L）分别比 Cu-BC/PDS 体系高 31 倍和 33 倍。•H 增强电子转移过程的降解机制是•H 攻击 DBP 的一个 Br 基团，然后在 MgCu-BC/PDS 体系中通过电子转移过程将脱溴中间产物矿化。总的来说，本研究在 PS-AOPs 中报告了一种用于废水中 EDAPs 选择性降解的新途径。
