Faculty of Forensic Medicine, Henan University of Science and Technology, Luoyang, China.
Sci Rep. 2023 Feb 2;13(1):1951. doi: 10.1038/s41598-023-28237-4.
Increased attention has been given to the removal of ionic liquids (ILs) from natural water environments. In this work, 5 kinds of 1-alkyl-3-methylimidazoliumtetrafluoroborate ([Cmim][BF] (n = 2, 4, 6, 8, 10)) ILs were degraded in an ultrasonic zero-valent zinc (ZVZ) and activated carbon (AC) micro-electrolysis system. Optimization of degradation conditions and the degradation levels were studied by high performance liquid chromatography, the surface morphology of the ZVZ and AC changed before and after the reaction were observed by scanning electron microscope. The degradation intermediates were detected by gas chromatography- mass spectrometry and ion chromatography, and inferred the degradation pathway. The degradation effect of [Cmim][BF] was best with ultrasonic assistance, pH 3 and an AC/ZVZ ratio of 1:1. The degradation of [Cmim][BF] in aqueous solution exceeded 91.7% in 120 min, and the mineralization level exceeded 88.9%. The surface of smooth and dense ZVZ particles became loose flocculent and the porous surface of AC became larger and rougher after reaction. The degradation pathway suggested that the imidazolium ring was sulfurized or oxidized, and then the ring was opened to form N-alkyl formamide and N-methyl formamide. ZVZ/AC micro-electrolysis combined with ultrasonic irradiation is an effective method to remove ILs, which provides new insight into IL degradation.
人们越来越关注从自然水环境中去除离子液体 (ILs)。在这项工作中，在超声零价锌 (ZVZ) 和活性炭 (AC) 微电解系统中降解了 5 种 1-烷基-3-甲基咪唑四氟硼酸盐 ([Cmim][BF] (n = 2, 4, 6, 8, 10)) ILs。通过高效液相色谱法研究了降解条件的优化和降解水平，通过扫描电子显微镜观察了 ZVZ 和 AC 反应前后的表面形貌变化。通过气相色谱-质谱和离子色谱检测了降解中间体，并推断了降解途径。在超声辅助、pH 3 和 AC/ZVZ 比为 1:1 的条件下，[Cmim][BF] 的降解效果最佳。在水溶液中，[Cmim][BF] 的降解在 120 分钟内超过 91.7%，矿化水平超过 88.9%。反应后，光滑致密的 ZVZ 颗粒表面变得疏松絮状，AC 的多孔表面变得更大、更粗糙。降解途径表明，咪唑环发生了硫化或氧化，然后环被打开形成 N-烷基甲酰胺和 N-甲基甲酰胺。ZVZ/AC 微电解结合超声辐射是去除 ILs 的有效方法，为 ILs 的降解提供了新的见解。
