The Gas-Absorption/Chemical-Reaction Method for Measuring Air-Water Interfacial Area in Natural Porous Media
AffiliationUniv Arizona, Dept Hydrol & Atmospher Sci
Univ Arizona, Sch Earth & Environm Sci, Dept Soil Water & Environm Sci
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationThe Gas-Absorption/Chemical-Reaction Method for Measuring Air-Water Interfacial Area in Natural Porous Media 2017, 53 (11):9519 Water Resources Research
JournalWater Resources Research
Rights© 2017. American Geophysical Union. All Rights Reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractThe gas-absorption/chemical-reaction (GACR) method used in chemical engineering to quantify gas-liquid interfacial area in reactor systems is adapted for the first time to measure the effective air-water interfacial area of natural porous media. Experiments were conducted with the GACR method, and two standard methods (X-ray microtomographic imaging and interfacial partitioning tracer tests) for comparison, using model glass beads and a natural sand. The results of a series of experiments conducted under identical conditions demonstrated that the GACR method exhibited excellent repeatability for measurement of interfacial area (A(ia)). Coefficients of variation for A(ia) were 3.5% for the glass beads and 11% for the sand. Extrapolated maximum interfacial areas (A(m)) obtained with the GACR method were statistically identical to independent measures of the specific solid surface areas of the media. For example, the A(m) for the glass beads is 29 (1) cm(-1), compared to 32 (3), 30 (2), and 31 (2) cm(-1) determined from geometric calculation, N2/BET measurement, and microtomographic measurement, respectively. This indicates that the method produced accurate measures of interfacial area. Interfacial areas determined with the GACR method were similar to those obtained with the standard methods. For example, A(ia)s of 47 and 44 cm(-1) were measured with the GACR and XMT methods, respectively, for the sand at a water saturation of 0.57. The results of the study indicate that the GACR method is a viable alternative for measuring air-water interfacial areas. The method is relatively quick, inexpensive, and requires no specialized instrumentation compared to the standard methods.
Note6 month embargo; published online: 22 November 2017
VersionFinal published version
SponsorsNIEHS Superfund Research Program [P42 ES04940]; China Scholarship Council