In this work a competitive transport of an equimolar mixtures of Zn(II), Cd(II), and Pb(II) across polymer inclusion membranes (PIMs) is presented. In PIMs di-2-ethylhexylphosphoric acid (D2EHPA) as well as commercial extractants, i.e. Cyanexo((R)) 272, 301, and 302 were used as ion carriers. The influence of nature extractants on cation transport selectivity and efficiency has been explored. Cyanex((R)) 301 and 302 used as ionic carriers for competitive transport of Zn(II), Cd(II) and Pb(II) give preferential selectivity order: Pb(II) > Cd(II) > Zn(II). The selectivity coefficients for Pb(II)/Cd(II) and Pb(II)/Zn(II) for transport with Cyanex((R)) 302 have been found, they were equal to 2 and 4.4, respectively. To understand the influence of plasticizers nature on Zn(II), Cd(II), Pb(II) ions transport through PIM, membranes with different compounds, i.e. dioctyl phthalate (DOP), o-nitrophenyl octyl ether ONPPE), bis(2-ethylhexyl) adipate (DOA), and tris(2-etylhexyl) phosphate (TOF) were prepared. The initial fluxes of metal ions increase in the following order of plasticizers: DOA < TOF < ONPOE, i.e. with their viscosity decrease, whereas DOP proved to be equally effective as ONPOE. The addition of 3,7-dinonyl-naphthalene-1-sulfonic acid into PIM with Cyanex((R)) 302 plays a role of a synergetic factor in the membrane process. A long-term experiment was carried out to demonstrate the durability of PIMs. The application of PIM transport process for 92% and 96% removal of lead(II) and cadmium(II), respectively, from technological sludge eluates is also shown. (C) 2006 Elsevier B.V. All rights reserved.