Extraction Behavior of Mercury(II) and Cadmium(II) in Ion Liquid Extraction System Using 1-Butyl-3-methyl-imidazolium Hexafluorophosphate and 8-Hydroxyl-Quinoline

摘要

The extraction behavior of metal ions (Hg~(2+) and Cd~(2+), M~(2+)) was investigated in ionic liquid (IL) extraction system using 1-butyl-3-methyl- imidazolium hexafluorophosphate ionic liquid ([Bmim]PF_6) as extraction solvent and 8-hydroxyl-quinoline (HQ) as extractant. The extraction percentage of M~(2+) using [Bmim]PF_6 was less than 5% without HQ. When sufficient HQ was included in IL phase, the extraction percentage of M~(2+) could be higher than 98%. The extracted species in the M~(2+)-[Bmim]PF_6-HQ system was neutral MQ_2 and the recovery of M~(2+) extracted into [Bmim]PF_6 can be achieved using 0.25 mol·L~(-1) HNO_3 as stripping agent. [Bmim]PF_6 can be recycled in the experiment.