4.7 Article

Degradation of imidazolium ionic liquids in a thermally activated persulfate system

期刊

CHEMICAL ENGINEERING JOURNAL
卷 412, 期 -, 页码 -

出版社

ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2021.128624

关键词

Ionic liquids; Thermally activated persulfate oxidation; Intermediate products; Degradation pathway; Toxicity assessment

资金

  1. National Natural Science Foundation of China [51538012, 21477121]
  2. CAS Key Laboratory of Urban Pollutant Conversion [KLUPCKF20201]

向作者/读者索取更多资源

Thermally activated persulfate oxidation was used for the degradation of ionic liquids, showing effective removal of ILs. Factors affecting the degradation included temperature, PS concentration, solution pH, and alkyl chain length, while intermediate products and degradation mechanism were identified. Free radicals generated in the activated PS system had different effects on degradation, with SO4?? radicals attacking the side chain and ?OH attacking the core, offering a potential environmentally friendly approach for ILs treatment.
Thermally activated persulfate (PS) oxidation, a clean source of sulfate radicals (SO4??), has been used as a promising advanced oxidation method for the treatment of organic contaminants. In this study, the degradation of ionic liquids (ILs) by thermally activated PS was investigated with 1-alkyl-3-methylimidazolium bromides (C4mimBr) as a model compound. The effects of various factors including temperature, initial IL and PS concentrations, solution pH, alkyl chain length of imidazolium cation, and common water constituents such as humic acid (HA), HCO3 - and Cl- were evaluated. Results showed that C4mimBr can be completely degraded in 2 h at 60 ?C, indicating effective removal of C4mimBr by thermally activated PS oxidation. The oxidation followed a pseudo-first-order kinetics model, and the rate constant increased with increasing temperature, PS concentration and initial solution pH. Alkyl chain length had no effect on the degradation. HA and Cl- had negative effects on C4mimBr removal, while 5 mM HCO3 - increased C4mimBr degradation. Multiple intermediate products were identified by HPLC-MS/MS and the degradation pathway and mechanism were proposed. The free radicals generated in the activated PS system (e.g., SO4?? and ?OH) showed different effects on the degradation. SO4?? radicals select to attack the substituted side chain of ILs cation, producing more chance for ?OH to attack the imidazolium core. Moreover, toxicity tests using bioluminescent bacteria Vibrio Qinghaiensis sp.-Q67 and nematode C. elegans demonstrated efficient detoxification of CnmimBr treatment. These findings may offer an environmentally friendly approach for ILs treatment in aqueous solution.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据