Robust AMP-PVC composite adsorbent with outstanding performance and integrity: a promising solution for selective cesium extraction from salt lake brines

Cesium recovery from salt lake brines remains a formidable challenge, primarily attributed to its low concentration and the dominance of competing ions. In this paper, we developed a novel AMP-PVC composite adsorbent through an emulsification-granulation method, leveraging ammonium phosphomolybdate (AMP) and polyvinyl chloride (PVC) for selective cesium extraction. The synthesized microspheres demonstrated an impressive cesium uptake capacity of 121 mg/g and achieved adsorption equilibrium within 6 h. The adsorption process adhered to the Langmuir monolayer chemisorption model, characterized by spontaneous and exothermic behavior, with a Gibbs free energy of –25.515 kJ/mol at 298 K. Significanly, the composite exhibited remarkable ion selectivity in multi-cation environments, boasting a distribution coefficient (K d ) exceeding 104 mL/g for Cs + . It also showcased excellent acid-base resistance, retaining 84 % of its initial capacity even after five regeneration cycles. Nanoindentation analysis further underscored the material’s outstanding mechanical properties, with a hardness of 0.045 GPa and an elastic modulus of 0.94 GPa, far surpassing those of conventional inorganic adsorbents in terms of mechanical integrity. These combined attributes of selectivity, durability, and mechanical robustness endow the AMP-PVC composite with unparalleled synergistic advantages, positioning it as a highly promising solution for industrial-scale cesium recovery from salt lake brines.