Zong Yang, Zhang Hua, Zhang Xiaomeng, Shao Yufei, Zeng Yunqiao, Ji Wenjie, Xu Longqian, Wu Deli
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
Chemosphere. 2021 Dec;285:131544. doi: 10.1016/j.chemosphere.2021.131544. Epub 2021 Jul 15.
Ruthenium (Ru)-activated peroxymonosulfate (the Ru/PMS process) is one of the most efficient PMS-based advanced oxidation processes for the abatement of organic contaminants. Here we interestingly found that phenyl methyl sulfoxide (PMSO) was significantly oxidized to phenyl methyl sulfone (PMSO) in the Ru/PMS process at the pH range of 3.0-6.0, with the conversion ratio of ΔPMSO to ΔPMSO was close to 100%, which favored the dominance of high-valent ruthenium-oxo species (RuO) instead of the widely-recognized radicals (i.e, hydroxyl radical and sulfate radical). Scavenging experiments further indicated that RuO was unreactive to tert-butyl alcohol, but could be scavenged by methanol and dimethyl sulfoxide. Besides, sulfamethoxazole, acetaminophen, carbamazepine, diclofenac, 2,4,6-trichlorophenol were readily degraded in the Ru/PMS process, but atrazine, ibuprofen, benzoic acid and 4-nitrobenzoic acid were barely removed, suggesting the high selectivity of RuO species. This study enriched the understandings on the mechanism of Ru-mediated PMS activation and the nature of RuO species.
钌（Ru）活化过一硫酸盐（Ru/PMS工艺）是用于去除有机污染物的最有效的基于过一硫酸盐的高级氧化工艺之一。在此，我们有趣地发现，在pH值为3.0 - 6.0的Ru/PMS工艺中，苯甲亚砜（PMSO）被显著氧化为苯甲砜（PMSO₂），ΔPMSO到ΔPMSO₂的转化率接近100%，这有利于高价钌氧物种（RuO）占主导地位，而非广泛认可的自由基（即羟基自由基和硫酸根自由基）。清除实验进一步表明，RuO对叔丁醇无反应，但可被甲醇和二甲基亚砜清除。此外，磺胺甲恶唑、对乙酰氨基酚、卡马西平、双氯芬酸、2,4,6 - 三氯苯酚在Ru/PMS工艺中易于降解，但莠去津、布洛芬、苯甲酸和4 - 硝基苯甲酸几乎未被去除，这表明RuO物种具有高选择性。本研究丰富了对Ru介导的PMS活化机制和RuO物种性质的认识。
