School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, Oregon, U.S.A.
Current address: Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, Maryland, U.S.A.
J Microsc. 2020 Feb;277(2):118-129. doi: 10.1111/jmi.12874. Epub 2020 Feb 17.
Colloidal transport and deposition are of both environmental and engineering importance. Easier access to x-ray microtomography (XMT) coupled with improved imaging resolution has made XMT a unique and viable tool for visualizing and quantifying these processes. Currently, there is scant information in the literature addressing colloid segmentation and analysis in saturated and unsaturated porous media, in particular related to spatial partitioning of colloids. To support this need, an approach to assign segmented colloidal particles and aggregates to different partitioning classes based on their proximity to different phases is presented here. The method uses different markers for each attachment site (e.g. wetting-nonwetting phase interfaces). An example XMT dataset from a drainage experiment is used to demonstrate the efficacy of the image processing algorithms. Flow conditions, and fluid and colloid properties, can thus be compared to the behaviour of colloids within the porous medium. This algorithm can help elucidate colloidal deposition mechanisms and the importance of different attachment sites, explore the importance of fluid properties, as well as the arrangement and shape of the colloids.
胶体的输运和沉积具有环境和工程双重重要性。更容易获得的 X 射线微断层扫描（XMT）与改进的成像分辨率使 XMT 成为可视化和量化这些过程的独特而可行的工具。目前，文献中几乎没有关于在饱和和非饱和多孔介质中胶体分段和分析的信息，特别是与胶体的空间分区有关的信息。为了满足这一需求，本文提出了一种根据胶体与不同相的接近程度将分段胶体颗粒和聚集体分配到不同分区类别的方法。该方法为每个附着点使用不同的标记（例如，润湿-非润湿相界面）。使用排水实验的 XMT 数据集示例演示了图像处理算法的有效性。因此，可以将流动条件以及流体和胶体特性与多孔介质中胶体的行为进行比较。该算法可以帮助阐明胶体沉积机制和不同附着点的重要性，探索流体特性的重要性，以及胶体的排列和形状。
