Separation of Uranium from Aqueous Solutions Using Al³⁺‐ and Fe³⁺‐modified Titanium‐ and Zirconium Phosphates

Abstract

Abstract The ability of four amorphous Al3+‐ and Fe3+‐doped titanium and zirconium sorbents to separate U(VI) from acidic aqueous solutions (pHinit=3, ionic strength 0.1 M established by NaNO3) was investigated using a batch technique and instrumental neutron activation analysis. All investigated sorbents were found to be chemically stable and remove considerable amounts of uranium from acidic aqueous solutions (pHinit=3). The scanning electron microscopic and powder‐X‐ray diffraction examination of the grains of the two investigated titanium phosphates after contacting the uranium solutions revealed the formation of sodium autunite (Na2(UO2)2(PO4)2 · 6‐8H2O) accompanied, in the case of the Fe3+‐doped titanium phosphate, by iron uranyl phosphate hydroxide hydrate (Fe(UO2)2(PO4)2(OH) · 7H2O). No crystal formation was observed in the cases of uranium sorbed by zirconium phosphates indicating the different sorption mechanism involved. Keywords: Uranium, separationtitanium, phosphateszirconium, phosphatessodium autunite