A new sorbent for selective separation of metal: Polyethylenimine methylenephosphonic acid

A new sorbent, the polyethylenimine methylenephosphonic acid ( PEIMPA), was synthesized from commercially available polyethylenimine. After characterization by (H-1, C-13, P-31) NMR, elementary analysis, UV/VIS and FTIR, the new ion exchange polymer PEIMPA has been investigated in liquid - solid extraction of a mixture of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II), and Zn(II) cations from a mineral residue of zinc ore dissolved in nitric acid. The selectivity of this polymer was studied as a function of pH. PEIMPA can sorb much higher amounts of Fe ion than Cd, Co, Cu, Ni, Pb, and Zn ions. The recovery of Fe( III) is almost quantitative. Because of this remarkable affinity, the PEIMPA resin has the potential for application in several fields. Further studies of the polymer are in progress.