摘要
制备了1-烷基3-甲基咪唑六氟磷酸盐[C_nMIm]PF_6(n=2,4,6)离子液体,以Cu^(2+)为对象,采用紫外光谱分析为检测方法,研究了不同离子液体对重金属离子的萃取性能,研究了螫合剂、萃取平衡时间、溶液pH、离子液体侧链长度、助溶剂以及离子液体用量等因素对萃取重金属的影响.结果表明,螯合剂对离子液体萃取重金属能力影响很大.当体系中未加入螯合剂时,离子液体对Cu^(2+)的萃取率仅为2%左右;而随着螯合剂双硫腙的加入,其萃取效率均达91%以上.3种离子液体中,以[C_6MIm]PF_6的萃取效率最好.同时离子液体在萃取重金属离子过程中,表现出很强的pH摆动效应,当pH<2时,Cu^(2+)的萃取率均小于2%,而当pH>8时,Cu^(2+)的萃取率均高于90%.利用这一摆动效应,可将Cu^(2+)从废水中分离出来.
Extraction of Cu^2＋ into hydrophobic ionic liquids of [Emim]PF6, [Bmim]PF6 and [Hmim]PF6 is investigated for examining their removal from wastewater. The results indicate that the extraction rates of Cu^2＋ is very low without chelator. However, the extraction rates are greatly enhanced from 2.04%,2.10% and 2.18% to 91.11%, 92.24% and 94.00% after the addition of chelator. The longer carbon bond the ionic liquids have, the better the extraction is. Maintime, pH has a great impact on the removal rates of Cu^2＋. When pH〈2, the extraction rates of Cu^2＋ are close to 2%. While for pH〉8, the extraction rates are above 90 %. The pH swing effect is used to strip the heavy metal ions from wastewater.
出处
《华中师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2010年第1期80-85,共6页
Journal of Central China Normal University：Natural Sciences
基金
国家自然科学基金项目(20705009)
武汉市晨光计划(200750731280)
