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, Mg_xCu-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 Mg_xCu-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 Mg_xCu-BC, inducing •H formation via electron transfer from Cu atoms during PDS activation, which was thermodynamically favorable. The degradation rate of DBP (k_obs, 0.0494 min^–1) and Br^– release (5.35 mg L^–1) in Mg₁Cu-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 Mg₁Cu-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) 的废水处理中，缺电子芳香族污染物 (EDAPs) 对非自由基途径具有抵抗力。为了探索 EDAPs 的有效降解途径，开发了 Mg _x Cu-biochar (BC) (x = 0.5, 1, 1.5) 活化的过二硫酸盐 (PDS)，它可以触发还原物质 (•H) 先还原 EDAPs，然后再还原促进还原中间体的电子转移降解。_{Mg掺杂在Mg x}中的作用研究了促进 PDS 活化和 2,4-二溴苯酚 (DBP) 降解的 Cu-BC。然后通过电子顺磁共振 (EPR)、化学探针和密度泛函理论 (DFT) 计算探索这些机制。结果表明，Mg 掺杂改善了 Mg _x Cu-BC 的金属-载体相互作用 (MSI)，在 PDS 活化过程中通过 Cu 原子的电子转移诱导了 •H 的形成，这在热力学上是有利的。DBP ( k _obs , 0.0494 min ^–1 ) 和 Br ^– release (5.35 mg L ^–1 ) 在 Mg ₁中的降解率Cu-BC体系分别是Cu-BC/PDS体系的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Mg ₁ Cu-BC/PDS 体系中通过电子转移过程将脱溴中间体矿化。总体而言，本研究报告了 PS-AOP 中选择性降解废水中 EDAP 的新途径。