A copper hexacyanoferrate/polymer/silica composite as selective sorbent for the decontamination of radioactive caesium

A novel composite material has been prepared for the on-column decontaminat ion of radioactive caesium. It consists of copper hexacyanoferrate retained in an anion-exchange polymeric layer bound to porous silica beads. Scannin g electron microscope images show the formation of a coating on the silica surface. The composition determined with neutron activation analysis corres ponds to a copper deficient hexacyanoferrate. The mechanical stability of t he support is excellent and the composite material is suitable for the on-c olumn recovery of radioactive caesium from liquid effluents. A high on-colu mn decontamination factor was found (less than 0.02% of initial caesium in the eluate after passing 5,000 column volumes) for several radioactive liqu id wastes.