离子液体萃取水中铜离子的研究

    Extraction of Cu2+ in Aqueous Solution With Room-temperature Ionic Liquids

    • 摘要: 研究了3种不同阳离子取代基咪唑类离子液体:1-丁基-3-甲基咪唑六氟磷酸盐(BmimPF6)、1-己基-3-甲基咪唑六氟磷酸盐(HmimPF6)、1-辛基-3-甲基咪唑六氟磷酸盐(OmimPF6)作为萃取剂对水中Cu2+的萃取能力,并与传统有机溶剂四氯化碳(CCl4)的萃取效果进行了对比.研究发现,上述离子液体本身对水中铜离子萃取能力很低,但加入螯合剂双硫腙后,萃取率可由原来的2.1%提高到93.1%,而且离子液体-双硫腙体系较四氯化碳-双硫腙体系有更高的萃取率;研究表明,随着离子液体咪唑阳离子取代烷基碳链长度的增加,其萃取效率逐渐下降;考察了溶液温度、pH值、萃取时间以及盐效应对萃取效率的影响,结果表明:温度对该萃取体系影响并不显著;当萃取时间大于6 min时,萃取基本达到平衡状态;溶液pH的变化对离子液体萃取体系的影响较大,酸性条件时萃取率较低,当pH>10时,萃取率均大于90%;盐度增加会降低离子液体萃取体系对水溶液中铜离子的萃取效率.

       

      Abstract: The extraction capability of Cu2+ in aqueous solution with imidazolium ionic liquids,BmimPF6,HmimPF6,and omimPF6,was studied in this research.It was found that the extraction efficiency for Cu2+ was quite low when only imidazaolium ionic liquids was used as extractant.On the other hand,with the addition of ditizone,the extraction efficiency for Cu2+ was enhanced from 2.1% to 93.1%,which was much higher compared to CCl4 extraction system.Meanwhile,the extraction efficiency for Cu2+ decreased with the increase of the alkyl chain length of the imidazolium cations.The effects of temperature,pH value,extraction time and salt effect were also studied.The temperature had no significant impact on the extraction efficiency,and extraction equilibration was reached within 6 minutes.The extraction efficiency strongly depended on the solution pH.It was 5.7% at pH<2,whereas it could be above 90% at pH>10.The addition of salts into the solution lowered the extraction efficiency.

       

    /

    返回文章
    返回