The novel composite mechanism of ammonium molybdophosphate loaded on silica matrix and its ion exchange breakthrough curves for cesium.

Long-lived Cs (over 30 years), a byproduct of the spent fuel fission processes, comprises the majority of high-level and prolific heat-generating waste in downstream processing. This study reports a novel sequential annealing mechanism with cross-linked network of polyvinyl alcohol, fabricating the composite of ammonium molybdophosphate loaded on silica matrix (SM-AMP20, 20wt% AMP) as an excellent granular ion exchanger for removal Cs. When the matrix is remarkably sequential annealed, well-dispersed SM-AMP20 particles are formed by firmly anchoring themselves on controlling the porous characteristics and stable structure. The material crystallizes in the complex cubic space group Pn-3m with cell parameters of crystalline AMP formation. The breakthrough curve of Cs by SM-AMP20 follows the Thomas model with a high removal rate of 88.23% (∼10mg/L of Cs) and breakthrough time as high as 26h (flow rate Q≈2.5mL/min and bed height Z≈11cm) at neutral pH. We also report on sorbents that could efficiently remove Cs ions from complex solutions containing different competitive cations (Na, Al, Fe, and Ni, respectively) in large excess. Furthermore, this study shows that there is a probability for SM-AMP20 to recycle cesium using an eluent of 2-3mol/L NHNO solution.