Synthesis of Ammonium Molybdopho-Sphate (AMP) Loaded Silica and Its Adsorption for Cesium

A ammonium molybdopho-sphate(AMP) loaded silica adsorbents(AMP-silica) was synthesized by crystallization method, and its characterization were investigated by XRD, BET and EPMA methods. Effects of contacting time and co-existing cations, such as Na⁺, K⁺, Ca²⁺ and Mg²⁺, were investigated by batch experiments, and column operations were also carried out. The AMP-silica has a very fast adsorption kinetics; it takes just 10 min to reach equilibrium. The distribution coefficient (K_d) of Cs⁺ is slightly decreased with increasing concentrations of co-existence cations. The adsorption follows a typical Langmuir model and the pseudo-second-order kinetic model. The adsorption capacity of Cs reaches as high as 0.390 mmol/g and 0.323 mmol/g in batch and column experiments in 0.6 mol/L Na, respectively.