(417o) Continuous Cesium Separation Using a Silica Microhoneycomb Supporting Ammonium Molybdophosphate

Honeycomb-type materials enable fast mass transfer without causing a serious hydraulic resistance. Therefore, these materials are thought to be suitable as adsorbents for continuous flow systems that require the processing of large quantities of fluids. We synthesized honeycomb-type adsorbents named microhoneycomb materials via directional freezing of a silica gel containing ammonium molybdophosphate (AMP) to investigate the potential of honeycomb-type materials to separate radioactive cesium ions from contaminated water. AMP has been known to remove cesium ions selectively in the presence of other competing alkali metal cations. Thus, AMP has been considered as an effective adsorbent for cesium ion separation. In this work, we report the synthesis of silica microhoneycomb where AMP particles are well-dispersed within its honeycomb walls. We show that the synthesized material (AMP-SMH) can readily remove cesium ions from a diluted aqueous solution (10-100 ppm Cs+) in batch and flow adsorption experiments. We also show that AMP-SMH causes a lower hydraulic resistance to a liquid flow than a packed column of silica-supported AMP particles.
Reference
[1] Mukai, S.R.; Nishihara, H.; Tamon, H., Chem. Commun. 2004, (7), 874-854.