A polymer material composed of cellulose triacetate as support, dioctyl terephthalate or o-nitrophenyl octyl ether as plasticizer (solvent) and tri-octylphosphine oxide as complexant, was investigated as a solid extractant for Pb(LT) ion sorption and as a membrane material for lead(II) ion transport. The influence of the counter-ion on sorption and transport processes was investigated. High permeabilities of PbI2 and Pb(SCN)(2) complexes were observed for both solvents studied. The transport mechanism is described in terms of diffusion coefficients (D) and distribution constants (K-p).