Abstract: |
Sorption of neptunium on naturally-occurring hematite (α-Fe2O3), magnetite (Fe3O4), goethite (α-FeOOH) and biotite (K(Mg,Fe)3AlSi3O10(OH)2) in 0.1 M? NaNO3 solution was studied at 30°C for pHs between 4 and 11. The mass to volume ratio was 1 g/l.
The sorption-desorption reaction was reversible for all the minerals in the pH ranges studied. The dependence of neptunium sorption on pH differed between goethite and the other three minerals; goethite showed a strong sorption at pHs above 6 while the sorption on hematite, magnetite and biotite occurred at pHs above 9. Other oxyhydroxides, lepidocrocite (γ-FeOOH) and boehmite (γ-AlOOH), have a similar pH dependence of sorption to goethite. The sorption on hematite was similar to that on alumina (α-Al2O3).
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