Sorption of caesium by complex hexacyanoferrates. v. a comparison of some cyanoferrates

Abstract

Abstract The properties of copper cyanoferrates and potassium cobalt ferrocyanide prepared at Imperial College and similar commercial products for caesium sorption have been investigated. Copper and cobalt based cyanoferrates have different chemical compositions and appear to be good adsorbers for the removal of caesium in aqueous solutions. Different caesium sorption mechanisms were observed for these cyanoferrates. A conventional ion exchange reaction, physical adsorption and a combination of the two processes were observed. The difference in caesium sorption mechanism also reflects the kinetics of the sorption process. Potassium copper ferrocyanide has the highest effective capacity but the caesium sorption rate is the slowest, whilst potassium cobalt ferrocyanide possesses faster kinetics but considerably lower effective capacity. Copper ferrocyanide tends to have better mechanical stability and moderate sorption kinetics and caesium uptake.