摘要
为探索重金属离子废水处理的绿色技术,研究了疏水性离子液体([Bmim]PF6、[Hmim]PF6和[Omim]PF6)对Cu(Ⅱ)和Ni(Ⅱ)的萃取性能,并与正丁醇相应的萃取效果进行了对比.结果表明:无螯合剂加入时,离子液体对Cu(Ⅱ)和Ni(Ⅱ)的萃取率均很低,螯合剂的加入可使Cu(Ⅱ)和Ni(Ⅱ)的萃取率分别由原来的2.31%和2.18%提高到99.89%和98.64%;离子液体阳离子取代烷基碳链长度的增加不利于Cu(Ⅱ)和Ni(Ⅱ)的萃取.与传统有机溶剂相似,离子液体在萃取重金属离子过程中具有很强的pH摆动效应,pH<2时,对Cu(Ⅱ)和Ni(Ⅱ)的萃取率几乎为0;pH>6时,对Cu(Ⅱ)和Ni(Ⅱ)的萃取率均大于90%.利用该pH摆动效应,可对Ni(Ⅱ)进行反萃取,实现离子液体的回收再利用.
The extraction ability of hydrophobic ionic liquids such as [Bmim]PF6, [Hmim]PF6 and [Omim]PF6 for Cu（ Ⅱ ） and Ni（ Ⅱ）was studied to explore the green technique on the treatment of waste water containing heavy metal ions, and extraction effect of hydrophobic ionic liquids was compared with that of n- butanol for Cu（ Ⅱ ） and Ni（ Ⅱ ）. The results indicate that the extraction efficiencies of both Cu（ Ⅱ ） and Ni（ Ⅱ ） are very low without chelator. However, the extraction efficiencies are greatly enhanced respectively from 2.31% and 2.18% to 99.89% and 98.64% for Cu（ Ⅱ ） and Ni（ Ⅱ ） with chelator . The longer of the ionic liquids＇ carbon bond, the worse for the extraction. Similar to traditional solvent such as n-butanol, ionic liquids have great pH swing effect in extracting heavy metals. When pH〈2, the extraction efficiencies for Cu（ Ⅱ ） and Ni（ Ⅱ ）are almost zero, while for pH 〉 6, the extraction efficiencies are above 90 %. The pH swing effect is used to strip the heavy metal ions such as Ni （ Ⅱ ） from ionic liquids and recovery and reuse of ionic liquids are realized.
出处
《大连海事大学学报》
CAS
CSCD
北大核心
2008年第3期17-20,共4页
Journal of Dalian Maritime University
基金
国家自然科学基金资助项目(20307002)
关键词
离子液体
重金属离子
萃取
ionic liquids
heavy metal ions
extraction
