The use of sodium polytungstate as an X-ray contrast agent to reduce the beam hardening artifact in hydrological laboratory experiments

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Abstract

Iodine is conventionally used as a contrast agent in hydrological laboratory experiments using polychromatic X-ray computed tomography (CT) to monitor two-phase Darcy flow in porous geological media. Undesirable beam hardening artifacts, however, render the quantitative analysis of the obtained CT images difficult. CT imaging of porous sand/bead packs saturated with iodine and tungsten-bearing aqueous solutions, respectively, was performed using a medical CT scanner. We found that sodium polytungstate (Na6H2W12O40) significantly reduced the beam hardening compared with potassium iodide (KI). This result is attributable to the location of the K absorption edge of tungsten, which is nearer to the peak of the polychromatic X-ray source spectrum than that of iodine. As sodium polytungstate is chemically stable and less toxic than other heavy element bearing compounds, we recommend it as a promising contrast agent for hydrological CT experiments.

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  • Berger M.J. Hubbell J.H. Seltzer S.M. Chang J. Coursey J.S. Sukumar R. Zucker D.S. Olsen K. 1998. XCOM: Photon Cross Sections Database. National Institute of Standards and Technology. http://www.nist.gov/pml/data/xcom/index.cfm/

  • Cardinal H.N. Holdsworth D.W. Drangova M. Hobbs B.B. Fenster A. 1993. Experimental and theoretical x-ray imaging performance comparison of iodine and lanthanide contrast agents. Med. Phys. 20 15-31.

  • Clausnitzer V. Hopmans J.W. 1999. Determination of phasevolume fractions from tomographic measurements in twophase systems. Adv. Water Resour. 22 577-584.

  • Heijs A.W. De Lange J. Schoute J.F.Th. Bouma J. 1995. Computed tomography as a tool for non-destructive analysis of flow patterns in macroporous clay soils. Geoderma 64 183-196.

  • Heindel T.J. 2011. A review of X-ray flow visualization with applications to multiphase flows. J. Fluids Eng. 133 article number 074001.

  • Hirono T. Takahashi M. Nakashima S. 2003. In situ visualization of fluid flow image within deformed rock by X-ray CT. Eng. Geol. 70 37-46.

  • Iglauer S. Paluszny A. Pentland C.H. Blunt M.J. 2011. Residual CO2 imaged with X-ray micro-tomography. Geophys. Res. Lett. 38 L21403.

  • Jinguuji M. Toprak S. Kunimatsu S. 2007. Visualization technique for liquefaction process in chamber experiments by using electrical resistivity monitoring. Soil Dyn. Earthq. Eng. 27 191-199.

  • Ketcham R.A. Carlson W.D. 2001. Acquisition optimization and interpretation of X-ray computed tomographic imagery: applications to the geosciences. Comp. Geosci. 27 381-400.

  • Minagawa H. Nishikawa Y. Ikeda I. Miyazaki K. Takahara N. Sakamoto Y. Komai T. Narita H. 2008. Characterization of sand sediment by pore size distribution and permeability using proton nuclear magnetic resonance measurement. J. Geophys. Res. 113 article number B07210.

  • Nakano T. Nakashima Y. Nakamura K. Ikeda S. 2000. Observation and analysis of internal structure of rock using X-ray CT. J. Geol. Soc. Jpn. 106 363-378.

  • Nakashima Y. 2000. The use of X-ray CT to measure diffusion coefficients of heavy ions in water-saturated porous media. Eng. Geol. 56 11-17.

  • Nakashima Y. 2003. Diffusivity measurement of heavy ions in Wyoming montmorillonite gels by X-ray computed tomography. J. Contam. Hydrol. 61 147-156.

  • Nakashima Y. Kamiya S. 2007. Mathematica programs for the analysis of three-dimensional pore connectivity and anisotropic tortuosity of porous rocks using X-ray computed tomography image data. J. Nucl. Sci. Technol. 44 1233-1247.

  • Nakashima Y. Nakano. T. 2012. Nondestructive quantitative analysis of a heavy element in solution or suspension by single- shot computed tomography with a polychromatic X-ray source. Anal. Sci. 28 1133-1138.

  • Nakashima Y. Watanabe Y. 2002. Estimate of transport properties of porous media by micro-focus x-ray computed tomography and random walk simulation. Water Resour. Res. 38 article number 1272.

  • Nakashima Y. Mitsuhata Y. Nishiwaki J. Kawabe Y. Utsuzawa S. Jinguuji M. 2011. Non-destructive analysis of oil-contaminated soil core samples by X-ray computed tomography and low-field nuclear magnetic resonance relaxometry: a case study. Water Air Soil Pollut. 214 681-698.

  • Oh J. Kim K.Y. Han W.S. Kim T. Kim J.C. Park E. 2013. Experimental and numerical study on supercritical CO2/brine transport in a fractured rock: Implications of mass transfer capillary pressure and storage capacity. Adv. Water Resour. (in press).

  • Remeysen K. Swennen R. 2006. Beam hardening artifact reduction in microfocus computed tomography for improved quantitative coal characterization. Int. J. Coal Geol. 67 101-111.

  • Shi J.Q. Xue Z. Durucan S. 2011. Supercritical CO2 core flooding and imbibition in Tako sandstone-influence of subcore scale heterogeneity. Int. J. Greenh. Gas Control 5 75-87.

  • Stock S.R. Nagaraja S. Barss J. Dahl T. Veis A. 2003. Xray microCT study of pyramids of the sea urchin Lytechinus variegatus. J. Struct. Biol. 141 9-21.

  • Tsuchiyama A. Hanamoto T. Nakashima Y. Nakano T. 2000. Quantitative evaluation of attenuation contrast of minerals by using a medical X-ray CT scanner. J. Miner. Petrol. Sci. 95 125-137.

  • Uemura S. Fukabori D. Tsushima S. Hirai S. 2012. Visualization and analysis of CO2 permeation process in a porous media by microfocus X-ray computed tomography. Trans. Jpn. Soc. Mech. Eng. Ser B 78 74-82.

  • Uemura S. Kataoka R. Fukabori D. Tsushima S. Hirai S. 2011. Experiment on liquid and supercritical CO2 distribution using micro-focus X-ray CT for estimation of geological storage. Energy Procedia 4 5102-5107.

  • Watanabe N. Ishibashi T. Tsuchiya N. Ohsaki Y. Tamagawa T. Tsuchiya Y. Okabe H. Ito H. 2013. Geologic core holder with a CFR PEEK body for the X-ray CT-based numerical analysis of fracture flow under confining pressure. Rock Mech. Rock Eng. 46 413-418.

  • Wellington S.L. Vinegar H.J. 1987. X-ray computerized tomography. J. Petrol. Technol. 39 885-898.

  • Werth C.J. Zhang C. Brusseau M.L. Oostrom M. Baumann T. 2010. A review of non-invasive imaging methods and applications in contaminant hydrogeology research. J.\ Contam. Hydrol. 113 1-24.

  • Wildenschild D. Sheppard A.P. 2013. X-ray imaging and analysis techniques for quantifying pore-scale structure and processes in subsurface porous medium systems. Adv. Water Resour. 51 217-246.

  • Wildenschild D. Vaz C.M.P. Rivers M.L. Rikard D. Christensen B.S.B. 2002. Using X-ray computed tomography in hydrology: systems resolutions and limitations. J. Hydrol. 267 285-297.

  • Zhou N. Matsumoto T. Hosokawa T. Suekane T. 2010. Pore-Scale visualization of gas trapping in porous media by X-ray CT scanning. Flow Meas. Instrum. 21 262-267.

  • Conceição P.C. Boeni M. Dieckow J. Bayer C. Mielniczuk J. 2008. Fracionamento densimétrico com politungstato de sódio no estudo da proteção física da matéria orgânica em solos. R. Bras. Ci. Solo 32 541-549.

  • Gregory M.R. Johnston K.A. 1987. A nontoxic substitute forhazardous heavy liquid - aqueous sodium polytungstate (3Na2WO4. 9WO3. H2O) solution. N. Z. J. Geol. Geophys. 30 317-320.

  • Munsterman D. Kerstholt S. 1996. Sodium polytungstate a new non-toxic alternative to bromoform in heavy liquid separation. Rev. Palaeobot. Palynology 91 417-422.

  • Skipp G.L. Brownfield I. 1993. Improved density gradient separation techniques using sodium polytungstate and a comparison to the use of other heavy liquids. US Geological Survey. Open-File Report 92-386.

  • Torresan M. 1987. The use of sodium polytungstate in heavy mineral separations. US Geological Survey. Open-File Report 87-590.

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