Retention behavior of As, Cr, B, Hg, and Cd on Teguline Clay samples

Mathieu Debure (1) , Christophe Tournassat (1) , Catherine Lerouge (1) , Benoît Madé (2) , Jean-Charles Robinet (2) , Sylvain Grangeon (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 ANDRA - Agence nationale pour le gestion des déchets radioactifs

Several low-level radioactive wastes (LLW) are characterized by their content in toxic elements (e.g. As, Cr, B, Hg, and Cd) in addition to radionuclides. Surficial aquitards are currently investigated for the containment of such radioactive and toxic waste, including Albian teguline Clay in the eastern part of the Paris Basin (Lerouge et al. 2015). Teguline Clay is dominated by clay fraction: chlorite, kaolinite, illite-smectite mixed layer minerals, illite and /or muscovite and glauconite (35-65 %) associated with quartz-feldspar silty fraction (18-58 %). The carbonate fraction varies a lot in quantity but is essentially represented by calcite with minor dolomite (0-30 %). Ankerite and siderite are detected as well in the formation. Furthermore, accessory minerals like pyrite, celestite, gypsum, phosphates, and iron oxi-hydroxides are present (Lerouge et al. (2015). This work aimed at quantifying the retention of As, Cr, B, Hg and Cd in the teguline Clay. Preliminary bulk chemistry measurements revealed significant B (106 ± 10 µg g-1) and Cr (115 ± 2 µg g-1) unperturbed geochemical background, and lower As (17 ± 4 µg g-1), Cd (3 ± 0.2 µg g-1) and Hg (4 ± 2 ng g-1) content.

Domains: Sciences of the Universe [physics]; Earth Sciences; Geochemistry; Environmental Sciences; Environmental Engineering

Mathieu Debure, Christophe Tournassat, Catherine Lerouge, Benoît Madé, Jean-Charles Robinet, et al.. Retention behavior of As, Cr, B, Hg, and Cd on Teguline Clay samples. Clay Conference 2017, Sep 2017, Davos, Switzerland. ⟨hal-01521010⟩