Sorption mechanism of carbon-14 by hardened cement paste
Book
·
OSTI ID:264449
- Hitachi Ltd., Ibaraki (Japan)
Carbon-14 sorption by cementitious materials should be enhanced to ensure the long term safety of radioactive waste repositories. The sorption mechanism of inorganic C-14 (CO{sub 3}{sup 2{minus}}) was investigated using batch sorption experiments and zeta potential measurements. The results suggested that C-14 was adsorbed onto the cement surface by an electrostatic force, due to the reaction between SiO{sub 2} and CaO contained in the cementitious composition. That is, SiO{sub 2} was originally negatively charged (SiO{sup {minus}}) in cement, but became positively charged through the interaction of Ca{sup 2+}. These positive sites on the SiO{sub 2} surface adsorbed inorganic C-14. Ordinary Portland cement (OPC) did not contain enough SiO{sub 2} compared with its CaO content to produce sufficient numbers of C-14 adsorption sites. The C-14 distribution coefficient (Kd) was increased from 2,000 to 7,000 mL/g by adding SiO{sub 2} to OPC.
- OSTI ID:
- 264449
- Report Number(s):
- CONF-951155--; ISBN 1-55899-315-0
- Country of Publication:
- United States
- Language:
- English
Similar Records
Prediction of water vapour sorption isotherms and microstructure of hardened Portland cement pastes
Sorption of radionuclides onto cement materials altered by hydrothermal reaction
Rehydration and microstructure of cement paste after heating at temperatures up to 300 deg. C
Journal Article
·
Tue Mar 15 00:00:00 EDT 2016
· Cement and Concrete Research
·
OSTI ID:22696551
Sorption of radionuclides onto cement materials altered by hydrothermal reaction
Conference
·
Thu Jul 01 00:00:00 EDT 1999
·
OSTI ID:20015872
Rehydration and microstructure of cement paste after heating at temperatures up to 300 deg. C
Journal Article
·
Tue Jul 01 00:00:00 EDT 2003
· Cement and Concrete Research
·
OSTI ID:20658314
Related Subjects
05 NUCLEAR FUELS
40 CHEMISTRY
ADSORPTION
CALCIUM OXIDES
CARBON 14
CARBONATES
CEMENTS
EXPERIMENTAL DATA
HYDROXIDES
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
LOW-LEVEL RADIOACTIVE WASTES
PERFORMANCE
RADIOACTIVE WASTE DISPOSAL
SAMPLE PREPARATION
SILICON OXIDES
SOLIDIFICATION
SORPTIVE PROPERTIES
WASTE FORMS
40 CHEMISTRY
ADSORPTION
CALCIUM OXIDES
CARBON 14
CARBONATES
CEMENTS
EXPERIMENTAL DATA
HYDROXIDES
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
LOW-LEVEL RADIOACTIVE WASTES
PERFORMANCE
RADIOACTIVE WASTE DISPOSAL
SAMPLE PREPARATION
SILICON OXIDES
SOLIDIFICATION
SORPTIVE PROPERTIES
WASTE FORMS