Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-14T05:17:56.668Z Has data issue: false hasContentIssue false
  • English
  • Français

Process tomography of diffusion, using PET, to evaluate anisotropy and heterogeneity

Published online by Cambridge University Press:  02 January 2018

J. Kulenkampff ,
M. Gründig ,
A. Zakhnini ,
R. Gerasch  and
J. Lippmann-Pipke
J. Kulenkampff*
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, 04318 Leipzig, Germany
M. Gründig
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, 04318 Leipzig, Germany
A. Zakhnini
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, 04318 Leipzig, Germany
R. Gerasch
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, 04318 Leipzig, Germany
J. Lippmann-Pipke
Affiliation:
Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, 04318 Leipzig, Germany
*
*E-mail: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Anisotropy and compositional and structural heterogeneity in clays are causes of considerable deviations from homogeneous diffusion, in particular in terms of direction-dependent transport rates and preferred transport zones. Conventional diffusion experiments, in which the sample is treated as a homogeneous black box in a concentration gradient, are interminable and insensitive to spatial effects. In contrast, tomographic imaging methods are capable of both reducing the amount of observation time required and revealing space-dependent features of the diffusion process.

In the present study, positron-emission-tomography (PET) was applied as the most sensitive quantitative spatiotemporal tomographic modality for direct observation of positron-emitting radiotracers in opaque media at reasonable resolution (1 mm) on a laboratory scale (100 mm).

Geoscientific applications of PET, or GeoPET, have revealed anisotropic and heterogeneous effects in diffusion experiments that have been conducted on Opalinus clay samples of different sizes, as well as on other rock types. Applying the Comsol Optimization Module to 2D-image sections of the PET tomograms, effective parameter values were derived, thereby quantifying the anisotropic diffusion.

Keywords

Opalinus claydiffusiontomographypositron emission tomographyheterogeneityanisotropy
Type
Research Article
Information
Clay Minerals , Volume 50 , Issue 3 , August 2015 , pp. 369 - 375
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2015 This is an Open Access article, distributed under the terms of the Creative Commons Attribution license. (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

References

Altmann, S., Tournassat, C., Goutelard, F., Parneix, J.-C., Gimmi, T. & Maes, N. (2012) Diffusion-driven transport in clayrock formations. Applied Geochemistry, 27, 463–478.10.1016/j.apgeochem.2011.09.015CrossRefGoogle Scholar
Boving, T.B. & Grathwohl, P. (2001) Tracer diffusion coefficients in sedimentary rocks: correlation to porosity and hydraulic conductivity. Journal of Contaminant Hydrology, 53, 85–100.10.1016/S0169-7722(01)00138-3Google Scholar
Gerasch, R. (2015) Simulation und Parameterschätzung von Na Diffusion in einem Opalinus-Bohrkern mittels Comsol Multiphysics und GeoPET-Datenabgleich. Brandenburg University of Technology, Senftenberg, Germany.Google Scholar
Gründig, M., Richter, M., Seese, A. & Sabri, O. (2007) Tomographic radiotracer studies of the spatial distribution of heterogeneous geochemical transport processes. Applied Geochemistry, 22, 2334–2343.10.1016/j.apgeochem.2007.04.024CrossRefGoogle Scholar
Kulenkampff, J., Gründig, M., Richter, M. & Enzmann, F. (2008) Evaluation of positron-emission-tomography for visualisation of migration processes in geomater-ials. Physics and Chemistry of the Earth, Parts A/B/C, 33, 937–942.10.1016/j.pce.2008.05.005CrossRefGoogle Scholar
Pearson, F.J., Arcos, D., Bath, A., Boisson, J.-Y., Fernández, A.M.,Gäbler, H.-E., Gaucher, E., Gautschi, A., Griffault, L., Hernán, P. & Waber, H.N. (2003) Mont Terri Project — Geochemistry of Water in the Opalinus Clay Formation at the Mont Terri Rock Laboratory. Reports of the Federal Office for Water and Geology (FOWG), Geology Series, 5, Eidgenössisches Departement für Umwelt, Verkehr, Energie und Kommunikation, Bern, Switzerland, p. 321.Google Scholar
Richter, M., Gründig, M., Zieger, K., Seese, A. & Sabri, O. (2005) Positron emission tomography for modelling of geochemical transport processes in clay. Radiochimica Acta, 93, 643–651.10.1524/ract.2005.93.9-10.643Google Scholar
Schikora, J. (2012) Simulation of diffusion-adsorption processes in natural geological media by means of COMSOL Multiphysics. Diploma thesis, Dresden Technical University, Dresden, Germany.Google Scholar
Sempere Roldan, P., Chereul, E., Dietzel, O., Magnier, L., Pautrot, C., Rbah, L., Sappey-Marinier, D., Wagner, A., Zimmer, L., Janier, M., Tarazona, V. & Dietzel, G. (2007) Raytest ClearPET(TM), a new generation small animal PET scanner. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 571, 498–501.10.1016/j.nima.2006.10.143CrossRefGoogle Scholar
Thielemans, K., Tsoumpas, C., Mustafovic, S., Beisel, T., Aguiar, P., Dikaios, N. & Jacobson, M.W. (2012) STIR: software for tomographic image reconstruction release 2. Physics in Medicine and Biology, 57, 867–883.10.1088/0031-9155/57/4/867CrossRefGoogle ScholarPubMed
Van Loon, L.R. & Eikenberg, J. (2005) A high-resolution abrasive method for determining diffusion profiles of sorbing radionuclides in dense argillaceous rocks. Applied Radiation and Isotopes, 63, 11–21.10.1016/j.apradiso.2005.02.001Google Scholar
Van Loon, L.R., Soler, J.M., Müller, W. & Bradbury, M.H. (2004) Anisotropic diffusion in layered argillaceous rocks: A case study with Opalinus Clay. Environmental Science & Technology, 38, 5721–5728.10.1021/es049937gGoogle Scholar
Zakhnini, A., Kulenkampff, J., Sauerzapf, S., Pietrzyk, U. & Lippmann-Pipke, J. (2013) Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus Clay, anhydrite and quartz. Computers & Geosciences, 57, 183–196.10.1016/j.cageo.2013.03.023CrossRefGoogle Scholar