Nonaqueous-phase liquid infiltration and immobilization in heterogeneous media: 1. Experimental methods and two-layered reference case
2007 (English)In: Vadose Zone Journal, ISSN 1539-1663, E-ISSN 1539-1663, Vol. 6, no 3, 471-482 p.Article in journal (Refereed) Published
Accurate data to understand the migration and entrapment ofnonaqueous-phase liquids (NAPLs) in heterogeneous formationsare presently lacking. A series of well-controlled laboratoryexperiments were conducted to investigate the infiltration andsubsequent immobilization of dense NAPLs in saturated heterogeneousmedia. The focus of this first study was the development ofa special experimental methodology for measuring the dynamicevolution of a NAPL plume in space and time. To demonstratethe method, a reference case of a two-layered formation consistingof two homogeneous sands separated by a dipping interface ispresented. The dipping formation in the reference case allowsthe study of NAPL behavior at texture interfaces under the influenceof both capillary and gravitational forces. The NAPL-saturationmeasurement methodology, based on a multiple-energy x-ray attenuationtechnique, correctly captured the known injected NAPL volumeas well as the general spreading and entrapment behavior inspace and time. Time-continuous measurements of NAPL saturationsallow the study of the history dependence of entrapped saturations.The Land model predicted the observed trend in the entrapmentbehavior well. The entrapment architecture was parameterizedusing spatial moments and moments of mass distribution at differentsaturations. The general features of the NAPL architecture weresuccessfully characterized by a simultaneous interpretationof these moments, while the domination of discontinuous or continuousNAPL was captured by the ganglia/pool ratio.
Place, publisher, year, edition, pages
2007. Vol. 6, no 3, 471-482 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-119272DOI: 10.2136/vzj2006.0171ISI: 000249015500005OAI: oai:DiVA.org:uu-119272DiVA: diva2:299948