Sorption of U(VI) and Np(V) onto diorite from Äspö HRL


Sorption of U(VI) and Np(V) onto diorite from Äspö HRL

Schmeide, K.; Gürtler, S.; Müller, K.; Steudtner, R.; Joseph, C.; Bok, F.; Brendler, V.

Sorption of the redox-sensitive actinides U and Np onto diorite obtained from Äspö Hard Rock Laboratory (HRL, Sweden) was studied by batch sorption experiments. The influence of various parameters, such as solid-to-liquid ratio (2 to 200 g/L), grain size (0.063 – 0.2 mm, 0.5 – 1 mm, 1 – 2 mm) and temperature (25 and 10°C), on the actinide sorption was studied under anoxic conditions (N2) applying a synthetic Äspö groundwater (pH 7.8, I = 0.178 M). The influence of grain size on actinide sorption was also investigated under aerobic conditions (pCO2 = 10−3.5 atm). Applying NaClO4 as background electrolyte, the actinide sorption onto diorite was studied as a function of ionic strength (I = 0.1 to 1 M, pH 7.8). Distribution coefficients, Kd values, were determined. Radionuclide speciation in solution was verified by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Furthermore, the sorption of U and Np onto diorite was also studied by in situ time-resolved attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy to characterize the sorbed species.

Keywords: Diorite; uranium; neptunium; sorption; speciation; TRLFS; ATR FT-IR spectroscopy

  • Lecture (Conference)
    1st Workshop of the Project "Crystalline rock retention processes" (CROCK), 22.-24.05.2012, Stockholm, Sweden
  • Poster
    1st Workshop of the Project "Crystalline rock retention processes" (CROCK), 22.-24.05.2012, Stockholm, Sweden
  • Contribution to proceedings
    1st Workshop of the Project "Crystalline rock retention processes" (CROCK), 22.-24.05.2012, Stockholm, Sweden
    1st Workshop Proceedings of the Collaborative Project “Crystalline Rock Retention Processes” (7th EC FP CP CROCK), KIT Scientific Reports 7629, Karlsruhe: KIT Scientific Publishing, 169-180 (2012)
  • Lecture (others)
    Status-Seminar 2012 "Nuclear Safety Research – From Reactors to Disposal", 11.-12.12.2012, Dresden, Germany

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Publ.-Id: 17156