Pb(II) removal with hydrophobic quaternary pyridinium salt and methyl isobutyl ketone

The extraction equilibrium behaviour of Pb(II) by noncommercial ionic liquid having extraction properties (3-[1-(hydroxyimine)undecyl]-1-propylpyridinium chloride) dissolved in MIBK was investigated. The obtained results show that extraction of lead(II) depends on the aqueous phase composition, contact time and the extractant concentration. The conducted stoichiometric studies indicated that lead(II) forms complexes with the studied quaternary salt (PbCl42 −)H(LR+) and (PbCl42 −)(LR+)2, which at the stripping stage can be decomposed by treatment with the 1% solution of oxalic acid and sodium oxalate (10:1, w/w). Separation test was carried out using synthetic solutions containing both Pb(II), Zn(II) and Fe(III) or Fe(II).