Lithium,rubidium and cesium ion removal using potassium iron(III) hexacyanoferrate(II) supported on polymethylmethacrylate

Potassium iron(III) hexacyanoferrate(II) supported on poly methyl methacrylate, has been developed and investigated for the removal of lithium, rubidium and cesium ions. The material is capable of sorbing maximum quantities of these ions from 5.0, 2.5 and 4.5 M HNO₃ solutions respectively. Sorption studies, conducted individually for each metal ion, under optimized conditions, demonstrated that it was predominantly physisorption in the case of lithium ion while shifting to chemisorption with increasing ionic size. Distribution coefficient (K _d) values followed the order Cs⁺ > Rb⁺ > Li⁺ at low concentrations of metal ions. Following these findings Cs⁺ can preferably be removed from 1.5 to 5 M HNO₃ nuclear waste solutions.