【摘要】 制备了1-烷基3-甲基咪唑六氟磷酸盐[C_nMIm]PF₆（n=2,4,6）离子液体,以Cu²⁺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Cu²⁺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[C₆MIm]PF₆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,Cu²⁺的萃取率均小于2%,而当pH>8时,Cu²⁺的萃取率均高于90%.利用这一摆动效应,可将Cu²⁺从废水中分离出来.更多还原

【Abstract】 Extraction of Cu²⁺ 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 Cu²⁺ 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 Cu²⁺ When pH<2, the extraction rates of Cu²⁺ 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.更多还原