An efficient composite ion exchanger of silica matrix impregnated with ammonium molybdophosphate for cesium uptake from aqueous solution

The silica matrix impregnated with salt of heteropoly molybdic acid (ammonium molybdophosphate, AMP) was fabricated using a polymer template method owing to the cross-linked network of polyvinyl alcohol-1788 in aqueous solvent, serving as an efficient ion exchanger for cesium (Cs) uptake from aqueous solution. The Cs ion adsorption onto the silica matrix impregnated with AMP (SM-AMP) from aqueous solution was investigated under the different experimental conditions, including several contact times, temperatures, initial Cs ion concentrations and acidities. The results revealed that the AMP could be well dispersed on the internal and external silica matrix. However, the granulating properties of SM-AMP became gradually poor as the AMP loading increased. It was found that the AMP with a loading of 20 wt% (SM-AMP20) not only possessed a relatively excellent ion exchange capacity (37.63 +/- 0.38 mg g(-1)), but also could be suitable for column operation experiment of Cs uptake. The results of Cs ion adsorption followed the pseudo second order kinetic model with a superior regression coefficient (R-2 > 0.994). In addition, a superior correlation coefficient and sum of the squared error analysis parameter between the experimental and fitting values of the isotherm demonstrated that Cs ion adsorption on the SM-AMP20 was fitted well using a Langmuir equation, and was a monolayer adsorption. The distribution coefficient (K-d) values were nearly constant at the nitric acid concentration ranges (0.001-3 M). Hence, the newly developed composite ion exchanger is a kind of potential efficient materials for Cs uptake from aqueous solution. (C) 2015 Published by Elsevier B.V.