Extraction of the heavy metals from the aqueous phase in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate by N-salicylideneaniline

The extraction behavior of heavy metals in aqueous phase by using the n-salicylideneaniline (sa) extractant in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was studied in room temperature. the extractant sa and the ionic liquid used were synthesized and characterized by the different methods of analysis like ir,1h-nmr,13c-nmr and elementary analysis. the extraction mechanism of different metals with surfactant sa was studied by varying the experimental parameters,such as ph and concentration of ligand. the results showed that the ph of aqueous medium had a great effect on the efficiency of the process and on the percentage of extraction. the optimum ph for ni2+,co2+ and pb2+ was 4,5 and 6 respectively,but the extraction process observed for cu2+ was independent from the ph of solution. using two different non-aqueous medium with the ligand to extract these metals under the same conditions shows that the extraction efficiency is higher in the ionic liquid then inthe chloroform. the association constants of complexes formed in ionic liquid for different metals are 2.74 107 for ni2+,2.29 106 for co2+ and 2.08 103 for pb2+. the stoichiometries of complexes between cu2+,co2+,ni2+,pb2+ and the ligand were 1:2 for all metals used.