Retention and diffusion of radioactive and toxic species on cementitious systems: Main outcome of the CEBAMA project

Grambow, Bernd; López‐García, Marta; Olmeda, J.; Grivé, M.; Marty, Nicolas; Grangeon, Sylvain; Claret, Francis; Lange, Steve; Deissmann, Guido; Klinkenberg, Martina; Bosbach, Dirk; Bucur, Crina Raluca; Florea, Ileana; Dobrin, Relu; Isaacs, Matthew; Read, David; Kittnerová, Jana; Drtinová, Barbora; Vopálka, D.; Çevirim-Papaioannou, Neşe; Ait-Mouheb, Nassim; Gaona, Xavier; Altmaier, M.; Nedyalkova, Latina; Lothenbach, Barbara; Tits, J.; Landesman, Catherine; Rasamimanana, Sabrina; Ribet, Solange

doi:10.1016/j.apgeochem.2019.104480

Cited by 22 publications

(16 citation statements)

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“…We also observed a negative correlation between leachate Se concentrations and the total Ca (Figure d), consistent with previous reports of Ca-selenite , associations in fly ash. The lack of correlation between leachate Se concentration and total Fe (Figure c) indicates the weak chemical association between the leachable Se and Fe-based phases.…”

Section: Resultssupporting

confidence: 92%

“…However, this explanation may be an oversimplified view of the reaction processes leading to the release of soluble As because fly ash contains other Ca-rich phases (Ca-sulfates, -carbonates, and -aluminosilicates) with variable extents of decomposition during hydration. 51,52 We also observed a negative correlation between leachate Se concentrations and the total Ca (Figure 5d), consistent with previous reports of Ca-selenite 53,54 associations in fly ash. The lack of correlation between leachate Se concentration and total Fe (Figure 5c) indicates the weak chemical association between the leachable Se and Fe-based phases.…”

Section: Loi Related To Feed Coal Basin and Power Plant Configuration...supporting

confidence: 91%

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Functional Predictor Variables for the Leaching Potential of Arsenic and Selenium from Coal Fly Ash

et al. 2023

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The release of leachates from intact coal ash impoundments is a concern due to the enrichment and mobilization of toxic elements such as arsenic (As) and selenium (Se). This study aims to explore the intrinsic properties of coal fly ash that correlate with the relative leachability of As and Se. We performed leaching experiments with 52 fly ash samples collected from 15 different U.S. power plants and representing coal feedstocks from the three major domestic regions. We assessed the mobilization potential of As and Se in fly ash based on standardized leaching protocols and performed multivariate and lasso regression analyses to explore correlations of leachable As and Se contents with characteristics such as major element contents, loss on ignition, and pH. The results of regression models indicated that major elements (Fe, Ca, and Al) for a wide range of fly ashes can serve as predictor variables for the leaching potential of As but not for Se. LOI and pH were not important predictive variables in the models. Both regression approaches resulted in relatively strong fits for leachable As (correlation coefficient R 2 = 0.78 for both models) compared to models for leachable Se (R 2 = 0.49). Overall, these results suggest that correlation models combined with on-site elemental analysis with portable analyzers may enable a screening method for leachable As in coal ash.

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Section: Resultssupporting

confidence: 92%

Section: Loi Related To Feed Coal Basin and Power Plant Configuration...supporting

confidence: 91%

Functional Predictor Variables for the Leaching Potential of Arsenic and Selenium from Coal Fly Ash

et al. 2023

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“…However, for cementation, they have only considered ordinary Portland cement as conditioning matrix and they have assumed from literature data that the beryllium corrosion rate would be too high according to the pH of the pore water solution (higher than 12). However, recent experimental data have shown strong uptake of beryllium in ordinary Portland cement, low-pH cements and calcium-silicate hydrated cements, showing that these types of cement could be used as matrices for Be(II) conditioning [15,16]. This uptake is controlled by sorption processes in the cement solid phases and the solubility has been found not relevant in the studied conditions.…”

Section: Introductionmentioning

confidence: 89%

“…In such conditions, the corrosion is continuous. Although some studies have shown a strong uptake of beryllium species in low and high alkaline cementitious matrices, the high beryllium corrosion leads to a continuous production of hydrogen gas, which can compromise the nuclear waste confinement [15,16].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of several conditioning matrices for the management of radioactive metal beryllium wastes

Bouhier

Cannes

Lambertin

et al. 2022

Journal of Nuclear Materials

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“…One of the most commonly used techniques prior to near-surface or underground disposal is the solidification of low-and intermediate-level radioactive waste with cementitious materials [2][3][4][5]. In assessing the long-term safety of radioactive waste repositories, the interaction between radionuclides and cement-based barrier materials is of great interest [6][7][8][9][10]. The interplay is dependent on both the nature of the radionuclides and the type of cement [10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Physico-Chemical Characteristics of Cement Superplasticizer Based on Polymelamine Sulphonate

Judžentienė,

Zdaniauskienė,

Ignatjev

et al. 2024

Materials

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Cementitious materials are used to construct an engineered barrier in repositories for radioactive waste. The cement matrix may contain a variety of organic compounds, some of which are polymeric admixtures used as plasticizers. Superplasticizers (SPs) are highly effective organic cement additives for reducing water amount, increasing workability, homogeneity, plasticity and the non-segregation of mortars and grouts, improving mechanical properties and resistance to destructive environments. SPs in cement could have an impact on the long-term safety of the disposals of radioactive waste. These organic agents can leach from the cementitious matrix into groundwater and may affect the migration behaviour of radionuclides. The detailed chemical composition and other characteristics of the cement (CEM I 42.5 R, Sweden) used for the leaching experiments were evaluated. It contained mainly CaO (52.51 ± 1.37, %), and the surface area of the cement particles was 13.2 ± 1.3 m2/g. An insignificant increase in pH (from 12.6 ± 0.1 to 12.8 ± 0.1) was observed for the leachates over 10 days. A commercially available cement superplasticizer based on polymelamine sulphonate (PMS) Peramin SMF10 (Peramin AB, Sweden) was chosen for the research. The product’s chemical composition was analysed using wavelength-dispersive X-ray fluorescence (WD-XRF) spectroscopy, while other physico-chemical properties of the PMS superplasticizer were assessed by Raman spectroscopy and thermo-gravimetric analysis. In aqueous solutions and powders of PMS, the same most intensive features were observed at 774 cm−1 (ring out-of-plane deformation), 977 cm−1 (C-N-C bending, SO stretching) and 1055 cm−1 (C-N=C bending) in the Raman spectra. At up to 270 °C, the polymer was thermally stable. Raman and UV/Vis spectroscopies were used to assess the rate of the alkaline degradation of PMS superplasticizer in different aqueous solutions. No changes were observed in the hydrolytic solutions with any of the above analytical methods over a period of 3 years. The results obtained revealed a good thermal and chemical stability (in highly alkaline media, pH = 9.9–12.9) of the PMS polymer.

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Retention and diffusion of radioactive and toxic species on cementitious systems: Main outcome of the CEBAMA project

Cited by 22 publications

References 50 publications

Functional Predictor Variables for the Leaching Potential of Arsenic and Selenium from Coal Fly Ash

Functional Predictor Variables for the Leaching Potential of Arsenic and Selenium from Coal Fly Ash

Evaluation of several conditioning matrices for the management of radioactive metal beryllium wastes

Evaluation of Physico-Chemical Characteristics of Cement Superplasticizer Based on Polymelamine Sulphonate

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