Imaging of colloidal deposits in granular porous media by X‐ray difference micro‐tomography

Abstract

[1] High resolution synchrotron-based X-ray computed microtomography (X-CMT) was used to identify the morphology of colloidal deposits formed in porous media. We show that difference microtomography -whereby a tomographic reconstruction is performed across an absorption edge -provides valuable information on the nature and location of the aggregates formed by the deposition of colloidal particles. Column experiments were performed using an idealized porous medium consisting of glass beads through which colloidal ZrO 2 particles were transported. Tomographic reconstructions of the porous medium and of the aggregate structure provide an unique opportunity to observe colloidal particle deposits and of their morphology. These results show that the local pore geometry controls particle deposition and that deposits tend to form in a rather heterogeneous manner in the porous medium.

Using X‐ray micro‐tomography and pore‐scale modeling to quantify sediment mixing and fluid flow in a developing streambed

“…The primary limitation of XMT is that only small samples (cores) can be used, with the height and width being limited by the X-ray beam geometry [Gaillard et al, 2007]. The minimum grain size that can be analyzed is currently about 1 mm.…”

A review of non-invasive imaging methods and applications in contaminant hydrogeology research

“…Gaillard et al (2007) examined the distribution of ZrO 2 particles in a glass bead pack after a suspension of the particles was injected via miscible displacement (Figure 6c). Li et al (2006) used non-synchrotron MT to examine the distribution of gold-coated microspheres in glass-bead and sand packs.…”

“…The images were adapted from a) Al-Raoush and Willson (2005a), b) Turner et al (2004), c) Gaillard et al (2007), d) Schnaar and Brusseau (2006a), e) and Schnaar and Brusseau (2006b) (PERMISSION BEING OBTAINED).…”

A proximity‐based image‐processing algorithm for colloid assignment in segmented multiphase flow datasets

“…Gaillard et al . (2007) used the Blob3D package to segment the colloids and then report colloid volume versus a dimensionless sphere normalized surface‐to‐volume ratio. Chen et al .…”