Synthesis and Evaluation of Task Specific Ionic Liquids for the Extraction of Heavy Metal IOns

Abstract

Six succinamide based ionic liquids were synthesized with imidazolium, pyridinium, ester imidazolium and quaternary amine based cations. These were termed as L1, L2, L3, L4,L5 and L6. Techniques used for the characterization of these synthesized ionic liquids were FTIR and NMR. The extraction efficiencies of Pb(II) Co(II) from aqueous phase was evaluated using synthesized ionic liquids on varying pH values and at different contact time. Extraction and separation efficiencies were also studied for Ni(II) and Co(II) by L1 and L3 in aqueous acidic media before and after adding a modifier (TBP). Experiments were carried to optimize contact time, initial pH of the aqueous phase and effect of TBP as a modifier on the extraction efficiencies of ionic liquids. Maximum extraction was observed at higher pH values and optimum contact time was observed to be 45 min. TBP was not found a good modifier for the extractants as it decreased the extraction efficiency of ionic liquid but separation between two metal ions was increased.