Analysis of a gas-phase partitioning tracer test conducted in an unsaturated fractured-clay formation

Michelle A. Simon, Mark L Brusseau

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The gas-phase partitioning tracer method was used to estimate non-aqueous phase liquid (NAPL), water, and air saturations in the vadose zone at a chlorinated-solvent contaminated field site in Tucson, AZ. The tracer test was conducted in a fractured-clay system that is the confining layer for the underlying regional aquifer. Three suites of three tracers were injected into wells located 14, 24, and 24 m from a single, central extraction well. The tracers comprised noble gases (traditionally thought to be nonsorbing), alkanes (primarily water partitioning), perfluorides (primarily NAPL partitioning), and halons (both NAPL and water partitioning). Observations of vacuum response were consistent with flow in a fractured system. The halon tracers exhibited the greatest amount of retardation, and helium and the perfluoride tracers the least. The alkane tracers were unexpectedly more retarded than the perfluoride tracers, indicating low NAPL saturations and high water saturations. An NAPL saturation of 0.01, water saturation of 0.215, and gas saturation of 0.775 was estimated based on analysis of the suite of tracers comprising helium, perfluoromethylcyclohexane and dibromodifluoromethane, which was considered to be the most robust set. The estimated saturations compare reasonably well to independently determined values.

Original languageEnglish (US)
Pages (from-to)146-158
Number of pages13
JournalJournal of Contaminant Hydrology
Volume90
Issue number3-4
DOIs
StatePublished - Mar 20 2007

Fingerprint

partitioning
Gases
tracer
Bromochlorofluorocarbons
clay
nonaqueous phase liquid
Water
saturation
Liquids
Helium
gas
Alkanes
Noble Gases
alkane
helium
Aquifers
water
test
analysis
well

Keywords

  • Alkane
  • Breakthrough curves
  • Capillary fringe
  • Clay
  • Fracture
  • Gas phase
  • Halon
  • Helium
  • NAPL saturation
  • Noble gas
  • Partitioning tracer
  • Perfluoride
  • Unsaturated
  • Vadose zone
  • Water content

ASJC Scopus subject areas

  • Earth-Surface Processes
  • Water Science and Technology
  • Environmental Chemistry

Cite this

Analysis of a gas-phase partitioning tracer test conducted in an unsaturated fractured-clay formation. / Simon, Michelle A.; Brusseau, Mark L.

In: Journal of Contaminant Hydrology, Vol. 90, No. 3-4, 20.03.2007, p. 146-158.

Research output: Contribution to journalArticle

@article{7446ca6de3c74095811042a295986c90,
title = "Analysis of a gas-phase partitioning tracer test conducted in an unsaturated fractured-clay formation",
abstract = "The gas-phase partitioning tracer method was used to estimate non-aqueous phase liquid (NAPL), water, and air saturations in the vadose zone at a chlorinated-solvent contaminated field site in Tucson, AZ. The tracer test was conducted in a fractured-clay system that is the confining layer for the underlying regional aquifer. Three suites of three tracers were injected into wells located 14, 24, and 24 m from a single, central extraction well. The tracers comprised noble gases (traditionally thought to be nonsorbing), alkanes (primarily water partitioning), perfluorides (primarily NAPL partitioning), and halons (both NAPL and water partitioning). Observations of vacuum response were consistent with flow in a fractured system. The halon tracers exhibited the greatest amount of retardation, and helium and the perfluoride tracers the least. The alkane tracers were unexpectedly more retarded than the perfluoride tracers, indicating low NAPL saturations and high water saturations. An NAPL saturation of 0.01, water saturation of 0.215, and gas saturation of 0.775 was estimated based on analysis of the suite of tracers comprising helium, perfluoromethylcyclohexane and dibromodifluoromethane, which was considered to be the most robust set. The estimated saturations compare reasonably well to independently determined values.",
keywords = "Alkane, Breakthrough curves, Capillary fringe, Clay, Fracture, Gas phase, Halon, Helium, NAPL saturation, Noble gas, Partitioning tracer, Perfluoride, Unsaturated, Vadose zone, Water content",
author = "Simon, {Michelle A.} and Brusseau, {Mark L}",
year = "2007",
month = "3",
day = "20",
doi = "10.1016/j.jconhyd.2006.09.010",
language = "English (US)",
volume = "90",
pages = "146--158",
journal = "Journal of Contaminant Hydrology",
issn = "0169-7722",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - Analysis of a gas-phase partitioning tracer test conducted in an unsaturated fractured-clay formation

AU - Simon, Michelle A.

AU - Brusseau, Mark L

PY - 2007/3/20

Y1 - 2007/3/20

N2 - The gas-phase partitioning tracer method was used to estimate non-aqueous phase liquid (NAPL), water, and air saturations in the vadose zone at a chlorinated-solvent contaminated field site in Tucson, AZ. The tracer test was conducted in a fractured-clay system that is the confining layer for the underlying regional aquifer. Three suites of three tracers were injected into wells located 14, 24, and 24 m from a single, central extraction well. The tracers comprised noble gases (traditionally thought to be nonsorbing), alkanes (primarily water partitioning), perfluorides (primarily NAPL partitioning), and halons (both NAPL and water partitioning). Observations of vacuum response were consistent with flow in a fractured system. The halon tracers exhibited the greatest amount of retardation, and helium and the perfluoride tracers the least. The alkane tracers were unexpectedly more retarded than the perfluoride tracers, indicating low NAPL saturations and high water saturations. An NAPL saturation of 0.01, water saturation of 0.215, and gas saturation of 0.775 was estimated based on analysis of the suite of tracers comprising helium, perfluoromethylcyclohexane and dibromodifluoromethane, which was considered to be the most robust set. The estimated saturations compare reasonably well to independently determined values.

AB - The gas-phase partitioning tracer method was used to estimate non-aqueous phase liquid (NAPL), water, and air saturations in the vadose zone at a chlorinated-solvent contaminated field site in Tucson, AZ. The tracer test was conducted in a fractured-clay system that is the confining layer for the underlying regional aquifer. Three suites of three tracers were injected into wells located 14, 24, and 24 m from a single, central extraction well. The tracers comprised noble gases (traditionally thought to be nonsorbing), alkanes (primarily water partitioning), perfluorides (primarily NAPL partitioning), and halons (both NAPL and water partitioning). Observations of vacuum response were consistent with flow in a fractured system. The halon tracers exhibited the greatest amount of retardation, and helium and the perfluoride tracers the least. The alkane tracers were unexpectedly more retarded than the perfluoride tracers, indicating low NAPL saturations and high water saturations. An NAPL saturation of 0.01, water saturation of 0.215, and gas saturation of 0.775 was estimated based on analysis of the suite of tracers comprising helium, perfluoromethylcyclohexane and dibromodifluoromethane, which was considered to be the most robust set. The estimated saturations compare reasonably well to independently determined values.

KW - Alkane

KW - Breakthrough curves

KW - Capillary fringe

KW - Clay

KW - Fracture

KW - Gas phase

KW - Halon

KW - Helium

KW - NAPL saturation

KW - Noble gas

KW - Partitioning tracer

KW - Perfluoride

KW - Unsaturated

KW - Vadose zone

KW - Water content

UR - http://www.scopus.com/inward/record.url?scp=33846630813&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846630813&partnerID=8YFLogxK

U2 - 10.1016/j.jconhyd.2006.09.010

DO - 10.1016/j.jconhyd.2006.09.010

M3 - Article

C2 - 17157956

AN - SCOPUS:33846630813

VL - 90

SP - 146

EP - 158

JO - Journal of Contaminant Hydrology

JF - Journal of Contaminant Hydrology

SN - 0169-7722

IS - 3-4

ER -