Sorption of Cs(I) on magnetite in the presence of silicates

Journal Article · Wed Mar 01 04:00:00 EST 2000 · Journal of Colloid and Interface Science

DOI:https://doi.org/10.1006/jcis.1999.6633· OSTI ID:20050902

Marmier, N; Fromage, F

The sorption of H{sub 4}SiO{sub 4} on magnetite has been qualified and quantified using three different surface complexation models, CCM, DLM, and NEM. The three tested models can account for the sorption of silicates using the same stoichiometry, one neutral species binding on a neutral surface, and the same constant, error aside. Experiments have also been performed to demonstrate that the sorption of dissolved silicates has a nonnegligible effect on the behavior of the surface of magnetite. Then, the sorption of cesium is insignificant on the neat surface of magnetite and is increased up to 10--20% when silicates are present in solution. A theoretical model, where the rule of electrostatics is pointed out, has been developed to account for the experimental observations. This model allows the reproduction of the sorption of cesium in the presence of dissolved silicates for the following four cases: Concentration of silicates under solubility limit, concentration of silicates over solubility limit, binary mixtures of silica and magnetite, and natural magnetite with silica as impurity. The reaction given in the model to account for the experimental observations proposes that silicates may act as a bridge between the surface of magnetite and cesium.

• Research Organization: Univ. of Reims (FR)
• OSTI ID: 20050902
• Journal Information: Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 1 Vol. 223; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CESIUM
MAGNETITE
MATHEMATICAL MODELS
RADIONUCLIDE MIGRATION
SILICATES
SORPTION