Modeling of neptunium(V) sorption behavior onto iron-containing minerals
- Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan)
- Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)
Sorption behaviors of neptunium(V) on naturally-occurring magnetite (Fe{sub 3}O{sub 4}) and goethite ({alpha}-FeOOH) in 0.1M NaNO{sub 3} electrolyte solution under aerobic conditions were interpreted using the surface complexation model (SCM). The surface properties of these materials were experimentally investigated by CO{sub 2}-free potentiometric titration, and SCM parameters for the constant capacitance model, such as protonation/deprotonation constants of the surface hydroxyl group, were determined. The number of negatively charged sorption sites of goethite rapidly increased with the increase of the bulk solution pH compared with that of magnetite and this tendency was similar to the pH dependence of neptunium sorption. This implies that the neptunyl cation, NpO{sub 2}{sup +}, plays a dominant role in possible sorption reactions. Assuming that the dominant surface complex is XO-NpO{sub 2}, modeling by means of SCM was carried out, and the results were found to agree with experimental data.
- OSTI ID:
- 382873
- Report Number(s):
- CONF-941075--; ISBN 1-55899-253-7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface complexation of neptunium (V) onto whole cells and cell componets of Shewanella alga
Temperature and pH dependence of neptunium(V) sorption on bentonite