Code: |
DBMCB98 |
Paper Type: |
Article |
Author(s): |
Del Nero M, Ben Said K, Made B, Clement A, Bontems G |
Title: |
Effect of pH and carbonate concentration in solution on the sorption of neptunium(V) by hydrargilite: Application of the Non-Electrostatic Model |
Journal: |
Radiochimica Acta
Volume: 81 Year: 1998 Pages: 133-141
ISSN-Print: 0033-8230 |
Internal Storage: |
V1611 |
DOI: |
10.1524/ract.1998.81.3.133 |
Abstract: |
Batch experiments were performed in order to investigate the influence of pH, neptunium concentration, and concentration of carbonate in solution on the sorption of Np(V) on a synthetic hydrargilite. The concentration of Np(V) at hydrargilite surface was found to be proportional to the concentration of dissolved Np(V) at equilibrium, within the Np(V) concentration range ≈ 10−13 to 10−7 M, in CO2-free 0.1 M NaClO4 solutions at pH = 7.45±0.05. The sorption of tracer concentration of Np(V) on hydrargilite was strongly pH-dependent. Increasing the total concentration of carbonate from about 0 to 10−2 M in the aqueous phase resulted in a net decrease of the extent of Np(V) uptake in the alkaline pH region. Surface complexation modeling suggested that Np(V) sorption behavior in carbonate solutions resulted mainly from a competition between surface complexation and aqueous carbonate complexation of NpO2+. The surface complexation reactions and conditional constants proposed in this study for the non-electrostatic model allowed an accurate description of the sorption behavior of Np(V) on hydrargilite over a wide range of pH and carbonate concentration of the aqueous phase. |
Comment: |
cited in [DSMCG99], [WAT01b] |
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