Redox sorption of Ce(III)/Ce(IV) on potassium bismuthate

Potassium bismuthate rods was synthesized in a form of elongated rods in non-aqueous methanol medium. The material morphology and structure were investigated using energy dispersive spectroscopy, scanning electron microscopy, and X-ray diffraction. The effects of annealing temperature on the material morphology and structure were investigated. Sorption kinetic study and ionic selectivity was investigated using batch technique. The sorption of Ce3+ on potassium bismuthate was found to be Ce3+ cation's ionic state selective process. Results showed that the chemical sorption of Ce3+ ionic state in KBiO3 follows the reduction of Bi5+ to Bi2- as a result of the formation of cerium bismuthide (Ce23+Bi2-O2). The suggested chemosorption mechanism includes equilibration parallel processes of the released K+ to form K2CeO2 and Bi2O3 that consumes the original material. The sorption kinetic has two different orders depending on contact time, isotherms fits adequately with Freundlich model and Dubinin-Radushkevich model. The material is considered a candidate for lanthanides radioactivity removal from aqueous media for radioactive waste disposal processes.