Details
| Original language | English |
|---|---|
| Pages (from-to) | 581-587 |
| Number of pages | 7 |
| Journal | Physics and chemistry of the earth |
| Volume | 32 |
| Issue number | 8-14 |
| Early online date | 17 Oct 2006 |
| Publication status | Published - 2007 |
Abstract
Clays play an important role in the design of HLW repositories. Serving as a buffer material between waste container and host rock, clays provide mechanical stability and radionuclide retardation due to advantageous hydrological and chemical properties. A crucial limitation, however, results from the fact that the affinity of natural clays for anionic species is very low. Modification of the clays with certain organic cations results in organo-clays, which have already proved high adsorption capacities for anions under laboratory conditions. In order to test the adsorption performance under various near-field conditions of a waste repository, experiments on the retention of radioiodide by different organo-clays were carried out under the influence of elevated temperatures and high-molar saline solutions. The results show that most of the investigated organo-clays exhibit stable structures and adsorption performances under the tested near-field conditions. Iodide adsorption remains at high levels in the temperature range under consideration for radioactive waste repositories. Adsorption reductions above 160 °C can be explained by both, losses of organo-cations and decreases of basal spacings. Under the impact of high-molar saline solutions, the organo-clays were able to adsorb considerable amounts of iodide in spite of extremely high concentrations of competing anions in the applied solutions.
Keywords
- Anion adsorption, Brine, Iodine, Organo-clays, Radioactive waste, Temperature
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Physics and chemistry of the earth, Vol. 32, No. 8-14, 2007, p. 581-587.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of temperature pre-treatment and high-molar saline solutions on the adsorption capacity of organo-clay minerals
AU - Riebe, Beate
AU - Bunnenberg, Claus
PY - 2007
Y1 - 2007
N2 - Clays play an important role in the design of HLW repositories. Serving as a buffer material between waste container and host rock, clays provide mechanical stability and radionuclide retardation due to advantageous hydrological and chemical properties. A crucial limitation, however, results from the fact that the affinity of natural clays for anionic species is very low. Modification of the clays with certain organic cations results in organo-clays, which have already proved high adsorption capacities for anions under laboratory conditions. In order to test the adsorption performance under various near-field conditions of a waste repository, experiments on the retention of radioiodide by different organo-clays were carried out under the influence of elevated temperatures and high-molar saline solutions. The results show that most of the investigated organo-clays exhibit stable structures and adsorption performances under the tested near-field conditions. Iodide adsorption remains at high levels in the temperature range under consideration for radioactive waste repositories. Adsorption reductions above 160 °C can be explained by both, losses of organo-cations and decreases of basal spacings. Under the impact of high-molar saline solutions, the organo-clays were able to adsorb considerable amounts of iodide in spite of extremely high concentrations of competing anions in the applied solutions.
AB - Clays play an important role in the design of HLW repositories. Serving as a buffer material between waste container and host rock, clays provide mechanical stability and radionuclide retardation due to advantageous hydrological and chemical properties. A crucial limitation, however, results from the fact that the affinity of natural clays for anionic species is very low. Modification of the clays with certain organic cations results in organo-clays, which have already proved high adsorption capacities for anions under laboratory conditions. In order to test the adsorption performance under various near-field conditions of a waste repository, experiments on the retention of radioiodide by different organo-clays were carried out under the influence of elevated temperatures and high-molar saline solutions. The results show that most of the investigated organo-clays exhibit stable structures and adsorption performances under the tested near-field conditions. Iodide adsorption remains at high levels in the temperature range under consideration for radioactive waste repositories. Adsorption reductions above 160 °C can be explained by both, losses of organo-cations and decreases of basal spacings. Under the impact of high-molar saline solutions, the organo-clays were able to adsorb considerable amounts of iodide in spite of extremely high concentrations of competing anions in the applied solutions.
KW - Anion adsorption
KW - Brine
KW - Iodine
KW - Organo-clays
KW - Radioactive waste
KW - Temperature
UR - http://www.scopus.com/inward/record.url?scp=33847694405&partnerID=8YFLogxK
U2 - 10.1016/j.pce.2006.02.060
DO - 10.1016/j.pce.2006.02.060
M3 - Article
AN - SCOPUS:33847694405
VL - 32
SP - 581
EP - 587
JO - Physics and chemistry of the earth
JF - Physics and chemistry of the earth
SN - 1474-7065
IS - 8-14
ER -