The frequent detection of 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) in various environments has raised concerns owing to its comparable or even higher environmental persistence and toxicity than perfluorooctane sulfonate (PFOS). This study investigated the plasma degradation of F-53B for the first time using a water film plasma discharge system. The results revealed that F-53B demonstrated a higher rate constant but similar defluorination compared to PFOS, which could be ascribed to the introduction of the chlorine atom. Successful elimination (94.8–100 %) was attained at F-53B initial concentrations between 0.5 and 10 mg/L, with energy yields varying from 15.1 to 84.5 mg/kWh. The mechanistic exploration suggested that the decomposition of F-53B mainly occurred at the gas-liquid interface, where it directly reacted with reactive species generated by gas discharge. F-53B degradation pathways involving dechlorination, desulfonation, carboxylation, C-O bond cleavage, and stepwise CF elimination were proposed based on the identified byproducts and theoretical calculations. Furthermore, the demonstrated effectiveness in removing F-53B in various coexisting ions and water matrices highlighted the robust anti-interference ability of the treatment process. These findings provide mechanistic insights into the plasma degradation of F-53B, showcasing the potential of plasma processes for eliminating PFAS alternatives in water.

中文翻译：

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通过等离子体放电有效降解水中的 F-53B 作为 PFOS 替代品：可行性和机制见解


6:2 氯化多氟醚磺酸盐 (F-53B) 在各种环境中的频繁检测引起了人们的关注，因为其环境持久性和毒性与全氟辛烷磺酸 (PFOS) 相当甚至更高。本研究首次使用水膜等离子体放电系统研究了 F-53B 的等离子体降解。结果表明，与 PFOS 相比，F-53B 表现出更高的速率常数，但脱氟效果相似，这可能归因于氯原子的引入。 F-53B 初始浓度在 0.5 至 10 mg/L 之间时，成功消除了污染物 (94.8–100%)，能量产量在 15.1 至 84.5 mg/kWh 之间。机理探索表明F-53B的分解主要发生在气液界面，直接与气体​​放电产生的活性物质发生反应。根据已鉴定的副产物和理论计算，提出了涉及脱氯、脱磺化、羧化、C-O 键断裂和逐步消除 CF 的 F-53B 降解途径。此外，在去除各种共存离子和水基质中的 F-53B 方面所表现出的有效性凸显了处理过程强大的抗干扰能力。这些发现为 F-53B 的等离子体降解提供了机制见解，展示了等离子体工艺消除水中 PFAS 替代品的潜力。