Measuring spatial variability of vapor flux to characterize vadose-zone VOC sources: Flow-cell experiments

J. Mainhagu, C. Morrison, M. Truex, M. Oostrom, Mark L Brusseau

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local-extraction point, whereas increases were observed for monitoring points located between the local-extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

Original languageEnglish (US)
Pages (from-to)32-43
Number of pages12
JournalJournal of Contaminant Hydrology
Volume167
DOIs
StatePublished - Oct 15 2014

Fingerprint

Volatile organic compounds
vadose zone
volatile organic compound
Vapors
Fluxes
Monitoring
monitoring
experiment
Experiments
Impurities
pollutant
tomography
Tomography
Gases
measuring
Mathematical models
gas
simulation
distribution
test

Keywords

  • Flow cell experiment
  • Source characterization
  • Vadose zone
  • Vapor phase tomography
  • VOC

ASJC Scopus subject areas

  • Water Science and Technology
  • Environmental Chemistry

Cite this

Measuring spatial variability of vapor flux to characterize vadose-zone VOC sources : Flow-cell experiments. / Mainhagu, J.; Morrison, C.; Truex, M.; Oostrom, M.; Brusseau, Mark L.

In: Journal of Contaminant Hydrology, Vol. 167, 15.10.2014, p. 32-43.

Research output: Contribution to journalArticle

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