Adsorption of cesium on copper hexacyanoferrate–PAN composite ion exchanger from aqueous solution

In this study, copper hexacyanoferrate–polyacrylonitrile composite (CHCF–PAN) was prepared and used as an ion exchanger for the separation of cesium from aqueous solution. Various characterization methods including XRD, FT-IR, TG–DSC, SEM, BET and XRF were utilized for the evaluation of the synthesized ion exchanger. In order to obtain the optimum conditions for the adsorption, the influence of pH of initial aqueous solution, contact time, solution temperature and presence of the interfering cations on the distribution coefficient of cesium onto CHCF–PAN sorbent were studied. Furthermore, adsorption thermodynamic parameters namely the standard enthalpy, entropy, and Gibbs free energy were calculated and it was found that the ion exchange reaction is an endothermic and spontaneous process. Langmuir, Freundlich, Dubinin–Radushkevich (D–R) and Temkin isotherm models were fitted to the obtained experimental sorption data and it was observed that the sorption of cesium on the synthesized sorbent was better represented by the Freundlich model. Finally, in order to calculate the dynamic adsorption capacity of the synthesized ion exchanger, the column experiments were also investigated.

• CHCF–PAN sorbent synthesized with porous crystalline, stable up to 200 °C.
• Kd of Cs on CHCF–PAN increase with higher pH, contact time, solution temperature.
• Cs adsorption on CHCF–PAN is an endothermic, spontaneous ion exchange reaction.
• Sorption of Cs on CHCF–PAN was better represented by the Freundlich model.
• Efficiency of adsorption column was 63.78%.