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Uptake of be(Ii) by cement in degradation stage i: Wet-chemistry and molecular dynamics studies

Çevirim-Papaioannou, Neşe; Han, Sangsoo; Androniuk, Iuliia; Um, Wooyong; Altmaier, Marcus; Gaona, Xavier

Abstract:
The uptake of beryllium by hardened cement paste (HCP, with CEM I 42,5 N BV/SR/LA type) in degradation stage I was investigated with a series of batch sorption experiments with 10$^{-6}$ M ≤ [Be(II)]0 ≤ 10$^{-2.5}$ M and 2 g·L$^{-1}$ ≤ [S/L] ≤ 50 g·L$^{-1}$. All experiments were performed under Ar atmosphere at T = (22 ± 2) °C. Solubility limits calculated for α-Be(OH)$_{2}$(cr) in the conditions of the cement pore water were used to define the experimental window in the sorption experiments. Beryllium sorbs strongly on HCP under all of the investigated conditions, with log Rd ≈ 5.5 (Rd in L⋅kg$^{-1}$). Sorption isotherms show a linear behavior with a slope of ≈+1 (log [Be(II)]$_{solid}$ vs. log [Be(II)]$_{aq}$) over four orders of magnitude (10$^{-8}$ M ≤ [Be(II)]$_{aq}$ ≤ 10$^{-4}$ M), which confirm that the uptake is controlled by sorption processes and that solubility phenomena do not play any role within the considered boundary conditions. The similar uptake observed for beryllium in calcium silicate hydrate (C-S-H) phases supports that the C-S-H phases are the main sink of Be(II) in cement. The strong uptake observed for Be(II) agrees with the findings reported for heavier metal ions, e.g., Zn(II), Eu(III), Am(III), or Th(IV). ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000139350
Veröffentlicht am 29.10.2021
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 18.10.2021
Sprache Englisch
Identifikator ISSN: 2075-163X
KITopen-ID: 1000139350
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Erschienen in Minerals
Verlag MDPI
Band 11
Heft 10
Seiten Art.-Nr. 1149
Schlagwörter beryllium; cement; sorption; degradation stage I; molecular dynamics
Nachgewiesen in Web of Science
Scopus
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