Abstract：
Electrochemical advanced oxidation processes (EAOPs) face challenging conditions in chloride media, owing to the co-generation of undesirable Cl-disinfection byproducts (Cl-DBPs). Herein, the synergistic activation between in-situ electrogenerated HClO and peracetic acid (PAA)-based reactive species in actual wastewater is discussed. A metal-free graphene-modified graphite felt (graphene/GF) cathode is used for the first time to achieve the electrochemically-mediated activation of PAA. The PAA/Cl- system allowed a near-complete sulfamethoxazole (SMX) degradation (kobs =0.49 min-1) in only 5 min in a model solution, inducing 32.7- and 8.2-fold rise in kobs as compared to single PAA and Cl- systems, respectively. Such enhancement is attributed to the occurrence of 1O2 (25.5 μmol L-1 after 5 min of electrolysis) from the thermodynamically favored reaction between HClO and PAA-based reactive species. The antibiotic degradation in a complex water matrix was further considered. The SMX removal is slightly susceptible to the coexisting natural organic matter, with both the acute cytotoxicity (ACT) and the yield of 12 DBPs decreasing by 29.4 % and 37.3 %, respectively. According to calculations, HClO accumulation and organic Cl-addition reactions are thermodynamically unfavored. This study provides a scenario-oriented paradigm for PAA-based electrochemical treatment technology, being particularly appealing for treating wastewater rich in Cl- ion, which may derive in toxic Cl-DBPs.
摘要：
电化学高级氧化工艺（EAOPs）在氯化物介质中面临挑战性的条件，由于不希望的Cl消毒副产物（Cl-DBPs）的共同产生。在这里，讨论了实际废水中原位电生成HClO与过乙酸（PAA）基活性物种之间的协同活化作用。首次使用无金属石墨烯改性的石墨毡（石墨烯/GF）阴极来实现PAA的电化学介导活化。PAA/Cl-系统允许在模型溶液中仅5分钟内几乎完全降解磺胺甲恶唑（SMX）（kobs=0.49min-1），与单一PAA和Cl-系统相比，导致kobs增加32.7倍和8.2倍，分别。这种增强归因于HClO和基于PAA的反应性物质之间热力学上有利的反应产生了1O2（电解5分钟后25.5μmolL-1）。进一步考虑了复杂水基质中的抗生素降解。SMX的去除对共存的天然有机物略有敏感，急性细胞毒性（ACT）和12个DBPs的产量分别下降了29.4%和37.3%，分别。根据计算,HClO积累和有机Cl加成反应在热力学上是不利的。这项研究为基于PAA的电化学处理技术提供了一个面向场景的范例，对于处理富含Cl-离子的废水特别有吸引力，这可能源于有毒的Cl-DBPs。
