HR: 1340h
AN: H53E-1469    [Abstracts]
TI: Characterizing Air-Water Interfacial Area for Variably Saturated Porous Media
AU: * Marble, J C
EM: jmarble@hwr.arizona.edu
AF: The University of Arizona, 429 Shantz Building, #38, Tucson, AZ 85712, United States
AU: Narter, M
EM: mnarter@email.arizona.edu
AF: The University of Arizona, 429 Shantz Building, #38, Tucson, AZ 85712, United States
AU: Schnaar, G
EM: gschnaar@gmail.com
AF: The University of Arizona, 429 Shantz Building, #38, Tucson, AZ 85712, United States
AU: Brusseau, M L
EM: brusseau@ag.arizona.edu
AF: The University of Arizona, 429 Shantz Building, #38, Tucson, AZ 85712, United States
AB: The critical role of the air-water interface in variably saturated porous media systems has received increased attention in recent years. The air-water interface is recognized to influence multi-phase flow, control interfacial retention of chemical contaminants, pathogens, and colloids, and mediate various mass-transfer processes. Unfortunately, examination of air-water interfacial phenomena and the potential impact of system properties and conditions has been constrained by a lack of means by which to measure air water interfacial areas. Imaging methods combined with computer-assisted tomography have been used for some time to examine the structure of porous media, as well as the configuration and distribution of fluids residing in porous media. The resolutions associated with these methods have, until recently generally been insufficient to quantitatively characterize fluid-fluid interfacial areas, especially for natural porous media. However, this impediment has been resolved by the availability of synchrotron X-ray sources. In this study, air-water interfacial areas as a function of water saturation were measured for several natural porous media using synchrotron X-ray microtomography. As expected, total (capillary-and film-associated) interfacial area increased with decreasing water saturation for all media. In addition, the magnitude was greater for the media with smaller median particle diameters. Capillary-associated interfacial area was also examined.
DE: 1832 Groundwater transport
DE: 1866 Soil moisture
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: 2007 Fall Meeting