Antimony lithium vanadium phosphate for sorption and chromatographic separation of cesium and europium ions from an aqueous solution

This study successfully developed an inorganic ion exchanger, antimony lithium vanadium phosphate (SbLiVP), with high efficiency for the selective removal of Cesium and Europium ions fromaqueous solutions. The material was prepared by the precipitation method and showed a stable crystalline structure with active surface functional groups capable of coordination and ion-exchange interactions. Surface characterization before and after ion sorption was done, confirming the uptake of the studied cations onto the sorbent with a pronounced preference for Cesium over Europium. Systematic adsorption experiments were carried out as a function of pH, contact time, and initial ion concentration. The sorbent displayed remarkable selectivity toward cesium ions, following the order: Cs(I) ˃˃ Eu(III). The application of the sorbent significantly enhanced the removal capacity as well as selectivity. Adsorption isotherms were fitted well to the Langmuir model, indicating monolayer chemisorption, with maximum capacities of 71 mg/g for Cs(I) and 14.5 mg/g for Eu(III), while thermodynamic analysis revealed the adsorption process is spontaneous and endothermic. Kinetic studies indicated that the process follows a pseudo-second-order model, suggesting that the rate-limiting step involved chemisorption through valence forces. Column breakthrough experiments demonstrated the practical applicability of SbLiVP with capacities of 24.5 mg/g for Cs(I) and 17.8 mg/g for Eu(III). Finally, efficient separation of the ions was achieved through stepwise elution with different concentrations of nitric acid, demonstrating excellent ion exchange reversibility. These results highlight SbLiVP as a promising sorbent for real radioactive wastewater treatment and selective cesium recovery.