| Autor: |
Pointeau, Ingmar, Piriou, Bernard, Fedoroff, Michel, Barthes, Marie-Genevieve, Marmier, Nicolas, Fromage, Francine |
| Zdroj: |
Journal of Colloid and Interface Science; April 2001, Vol. 236 Issue: 2 p252-259, 8p |
| Abstrakt: |
The sorption mechanisms of Eu3+on calcium silicate hydrate (CSH) phases of hydrated cement were investigated as a tool for the prediction of the behavior of trivalent radionuclides with aged/degraded cements in radioactive waste repositories. Four techniques were used: site-selective and time-resolved luminescence spectroscopy, XPS, high-resolution SEM coupled with EDX, and XRD. Results showed that europium is not precipitated in the solution despite its low solubility limit. It is strongly retained on CSH, resulting in a more than 99.8% sorption rate. Two main sorption sites were characterized by luminescence spectroscopy. One site, with a long lifetime, can be interpreted as Eu included in the framework of CSH. Another one, with a shorter lifetime, can be interpreted as a site with a hydrated environment that is high but is less than that of europium hydroxide. It corresponds to superficial complexation or precipitation. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full Text from ScienceDirect