The combined inorganic ion-exchanger, which contains zirconium hydrophosphate and phosphomolybdic acid, was prepared by sol-gel method. The adsorption and migration of Na+ and Cs+ ions adsorbed on ion-exchanger were investigated. The high selectivity towards Cs+ ions was found. The selective removal of Cs+ ions was studied using combined inorganic ion-exchanger and organic one Dowex-50WX2 as a transport media. The possibility of 98% cesium removal from sodium containing solution with simultaneous eight times concentrating in cathode compartment is shown. (C) 2004 Elsevier B.V. All rights reserved.