Alternatives to Nitric Acid Stripping in the Caustic‐Side Solvent Extraction (CSSX) Process for Cesium Removal from Alkaline High‐Level Waste

Understanding the sorption behaviour of Pu/U on zirconium phosphosilicate prepared by gelation route

Zirconium phosphosilicate (ZPS) has been prepared by gelation route for its ion exchange applications. ZPS was characterised by X-ray diffraction technique (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), Fourier transformed Infrared Spectrometry (FTIR) and surface area analysis. K+ ion exchange behaviour was studied by pH titration. The material was found to extract Pu selectively over U from different mineral acids. Pu sorption behaviour on ZPS packed column was also been carried out. The pore volume was evaluated as 0.1336 mL g−1. The FTIR revealed the presence of –OH and PO4 3− groups on the surface of the material, while the SEM image indicates the irregular morphology and size of the sorbent. Different isotherm model: Langmuir, Freundlich, Dubinin–Rodushkevich and Temkin were used to understand the nature of sorption, while Lagergren 1st order, Intraparticle diffusion and pseudo 2nd order kinetics were used for modelling sorption kinetics. Suitable elution method was used for quantitative stripping of plutonium from sorbent. The radiolytic stability of the sorbent was evaluated upto 1500 kGy. A comparative evaluation of the sorption process has also been carried out with that reported in literature.