Preparation of PAN-zeolite 4A composite ion exchanger and its uptake behavior for Sr and Cs ions in acid solution

A PAN-4A composite ion exchanger containing about 80% 4A powder was prepared to remove strontium and cesium ions from acidic solution. The SEM image of the fracture of composite bead showed that zeolite 4A powder was dispersed homogenously and the pores were well formed. The mean pore size of composite bead was 0.14 mum and its porosity was about 74%, which is much higher in comparison with the existing inorganic adsorbent beads. The acid and radiation stability tests showed that PAN-4A was stable against acid solution higher than pH2 and radiation dose less than 1.89 x 10(8) rad, respectively. Ion exchange tests showed that the PAN-4A was selective for Sr ion. The distribution coefficients of PAN-4A for Sr and Cs ions at pH 2 were 2 x 10(4) mL/g and 280 mL/g, respectively. The ion exchange capacities (q(s)) of PAN-4A for Sr and Cs ions at pH 2, which are modeled by Dubinin-Polanyi equation, were 3.92 meq/g and 2.47 meq/g, respectively.