摘要
针对含锌废水选择性处理问题,在不同微波强度合成条件下制备硫脲基疏水性咪唑离子液体,并对含Zn^(2+)等重金属废水进行了萃取处理,考察了盐浓度、pH、超声波、微波强度对萃取效果的影响;进一步研究了复合萃取体系的萃取效果及机理。结果表明,该离子液体可用于一定盐(1%~5%Na Cl)浓度下Zn^(2+)等重金属的选择性分离,并对p H、超声波等因素的影响表现出良好的适应性。微波强度为800 W时合成的离子液体体系纯度可达96%,对Zn^(2+)的萃取率可达90.4%,且90%硫脲基咪唑离子液体与10%非功能性咪唑离子液体组成的复合萃取体系比单一的功能性离子液体对Zn^(2+)的萃取率提高7%左右。这是由于体系内聚力减小、Zn^(2+)进入体系所受空间位阻减少、有效活性位点增加,使复合离子液体萃取体系表现出更好的萃取性能。
Thiourea-based imidazole ionic liquid is prepared under different microwave intensity synthesis conditions,and used in extraction treatment for wastewater contained Zn^(2+)and other heavy metals. Effects of salt concentration,p H,ultrasonic wave and microwave intensity on the extraction efficiency are investigated,and the extraction effect and mechanism of the composite extraction system are further studied.Results show that the prepared ionic liquid can be used for the selective separation of heavy metals such as Zn^(2+)at a certain salt concentration,and shows good adaptability under the influence of p H and ultrasonic wave.The purity of the ionic liquid synthesized at 800 W can reach96%,and its extraction ratio to Zn^(2+)can reach 90. 4%.The composite extraction system consisting of 90% thiourea-based imidazole ionic liquid and 10% non-functional imidazole ionic liquid has raised the extraction rate to Zn^(2+) by about 7%comparing with a single functional ionic liquid. This may be due to the decrease of cohesive force in the system,which leads to a decrease of steric hindrance for Zn^(2+) entering the system and an increase of active site,eventually resulting in better performance of the composite ionic liquid extraction system.
作者
刘燕泽华
师维江
湛含辉
LIU Yan-ze-hua;SHI Wei-jiang;ZHAN Han-hui(School of Environment Science and Spatial Informatics,China University of Mining and Technology,Xuzhou 221000,China)
出处
《现代化工》
CAS
CSCD
北大核心
2021年第2期114-119,共6页
Modern Chemical Industry
基金
国家自然科学基金(51574238)
大学生创新训练项目(201810290036)。
关键词
硫脲基
离子液体
萃取
空间位阻
内聚力
thiourea
ionic liquid
extraction
steric hindrance
cohesiveness
