The novel composite mechanism of ammonium molybdophosphate loaded on silica matrix and its ion exchange breakthrough curves for cesium.
Long-lived137Cs (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+, Al3+, Fe3+, and Ni2+, 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 NH4NO3solution.
State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, PR China.
Hao
H
Deng
State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, PR China; School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, PR China; National Defense Key Discipline Laboratory for Nuclear Wastes and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010, PR China. Electronic address: superfigure@163.com.
Yuxiang
Y
Li
State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, PR China.
Lang
L
Wu
School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, PR China.
Xue
X
Ma
Breakthrough curves; Cesium uptake; Competitive reaction; Ion exchanger; Sequential annealing mechanism