Ion-exchange studies of yttrium doped zirconium phosphates for use in the remediation of nuclear waste

There has been considerable amount of interest in the ion-exchange properties of layered zirconium phosphates. This interest has been renewed due to potential applications in the remediation of nuclear waste. They are believed to be preferred to the conventional ion-exchange materials due to their increased stability under acid conditions. The ability of the material to withstand low pH is crucial as the legacy waste pools have very low pH. It has been well documented that substituting metals with different radii into material’s framework can alter the ion-exchange properties of the material due to differences in the crystal structure and the interactions between the framework and the non-framework ions. The work presented here focuses on the synthesis and characterisation of a series of α-zirconium phosphate materials doped with trivalent cations (Y, Fe, Ce) of which the results indicate that complete solid solutions were not formed for iron-zirconium phosphate and cerium-zirconium phosphate, whereas solubility limits exist for yttrium-zirconium phosphate. The new yttrium-zirconium phosphates obtained were characterised by analytical techniques such as XRD, XRF, SEM/EDAX, MAS-NMR and FT-IR. The structural refinement of these materials was carried out and a study of the doping effect was also done to conclude that yttrium substitution into the zirconium phosphate framework did not follow Vegard’s law. Finally, ion exchanges of the inactive ions of Cs, Sr and Co commonly found in nuclear waste was carried out using single ion exchange and competitive exchange experiments with Na, Mg and Ca as interfering ions.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Central Lancashire

Year dc:date.issued

2016

Author dc:creator

• Suri, Gurpreet

• F200 - Materials science

Language dc:language

en