guest ::
| Home > Publications database > Comparative study of radium and strontium behaviour in contact with cementitious materials |
| Home > Publications database > Comparative study of radium and strontium behaviour in contact with cementitious materials |
| Journal Article | FZJ-2020-04088 |
; ; ; ; ; ;
2020
Elsevier Science
Amsterdam [u.a.]
This record in other databases: 
Please use a persistent id in citations: http://hdl.handle.net/2128/25949 doi:10.1016/j.apgeochem.2020.104713
Abstract: A comparative study of the sorption behaviour of radium and strontium was performed on various cementitiousmaterials including crushed hardened cement pastes (HCP) and concretes as well as a synthesised calcium silicatehydrate (CSH) phase.Rd values obtained for the Ra and Sr uptake on commercial cement materials were in the range of50–380 L kg-1 and 10–30 L kg-1, respectively. No significant difference between the distribution ratios of theisotopes 226Ra and 223Ra was observed in the studied liquid to solid (L/S) ratio range, although different isothermswere determined. The Rd values for Ra were found to increase with increasing L/S ratio. The cause of thiseffect is obviously the non-linearity of the sorption isotherm, here of the convex type. In contrast, Sr uptakeseemed to be largely unaffected by variation of L/S ratios; this indicates an isotherm of almost linear type.Sorption experiments with the CSH phase confirmed the distinctive differences in the sorption behaviour betweenRa and Sr as expected, with Rd values significantly higher for Ra. Similarly, the difference between realcementitious materials and the pure CSH phase was confirmed, indicating that the sorption of alkaline earthelements is mainly due to uptake by CSH.The kinetics of Ra and Sr uptake on cementitious materials were evaluated by a set of models describing thesorption in heterogeneous systems based on different rate-controlling processes. The FD (film diffusion) model inthe case of Ra, and the ID (diffusion in inert layer) model in the case of Sr provided the best fits.The influence of temperature on the kinetics of radium sorption was studied, suggesting change in the shape ofisotherm with increasing temperature. Evaluation of sorption kinetic data yielded values of the apparent activationenergy of the uptake process.Complementary through diffusion experiments using compacted crushed HCP confirmed and extended thefindings obtained by evaluation of the batch sorption experiments performed with Ra and Sr.
; 
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz
; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection
|
The record appears in these collections: |
PDF
PDF (PDFA)