Polymer inclusion membranes (PIMs) consisting of cellulose triacetate (CTA) as a polymer matrix, 2-nitrophenyl n-octyl ether (NPOE) as a solvent and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) or N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA) as a carrier were developed, and the facilitated transport of cerium(III) ions using the PIMs was investigated experimentally. It was observed that the present PIMs were very effective to transport cerium(III) ions from the feed phase to the strip phase. The transport rate was strongly influenced by the experimental conditions such as the solvent/polymer ratio, the operating temperature, the membrane thickness, the carrier concentration and the feed concentration. The experimental results indicated that the transport was controlled by the diffusion of the ion-carrier complex in the membrane. (C) 2004 Elsevier B.V. All rights reserved.