Sorption of trivalent plutonium onto UO2 and the effect of the solid phase on the Pu oxidation state
Artikel i vetenskaplig tidskrift, 2005
A problem with plutonium in sorption studies
is its tendency to occur in a mix of oxidation states. This
work was a study of the sorption of plutonium on the solid
phase UO2 in a perchlorate medium as a function of pH
where plutonium is kept in its trivalent oxidation state.
Experiments also showed that uranium(IV) oxide can reduce
Pu(IV) to Pu(III) in an acidic solution and maintain it in that
state. It was observed at the same time that the chemically
inert solid phases TiO2 and ThO2 possibly increase the rate
of disproportionation of Pu(IV) at a pH of about 0.5. In
accordance with previous studies MnO2 was found to have an
oxidizing effect, converting Pu(IV) into Pu(VI).
A comparison is made between the sorption of Th(IV),
Pu(III) and Co(II) on UO2 and TiO2, and Pu(VI) on TiO2.