In this study the separation of cadmium(II) from iron(III) has been successfully realized by a hybrid liquid membrane (HLM) containing tri-n-octylamine (TNOA, R3N)-secondary octylalcohol (ROH)-kerosene. The effect of different variable on the separation has been carefully studied. The apparatus composed of three compartments, including a reservoir of organic solution, with double solid supports was used in this study. The experiments show that the transport of Cd(II) ions is coupled by the co-transport flow of protons and the nitric acid in the feed phase of the HLM system can apparently improve the separation efficiency of cadmium(II) from iron(III). The loss of TNOA in the membrane phase was determined. The experiments demonstrated that the HLM can automatically and continuously replenish the membrane supports pores by the membrane solution (organic phase). (C) 2007 Published by Elsevier B.V.