TY - JOUR
T1 - Using a gas-phase tracer test to characterize the impact of landfill gas generation on advective-dispersive transport of VOCs in the vadose zone
AU - Monger, Gregg R.
AU - Duncan, Candice Morrison
AU - Brusseau, Mark L.
N1 - Funding Information:
Acknowledgments This research was supported in part by the NIEHS Superfund Basic Research Program (Grant no. ES 4940). The support of Pima County Solid Waste Management Department, those at Malcolm Pirnie, Inc., and Tracer Research Corp. is gratefully acknowledged. We thank members of the Contaminant Transport Group for their assistance in sample collection and analysis. We also thank the reviewers for their constructive comments.
Publisher Copyright:
© 2014 Springer International Publishing Switzerland.
PY - 2014/12
Y1 - 2014/12
N2 - A gas-phase tracer test (GTT) was conducted at a landfill in Tucson, AZ, to help elucidate the impact of landfill gas generation on the transport and fate of chlorinated aliphatic volatile organic contaminants (VOCs). Sulfur hexafluoride (SF6) was used as the nonreactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well and analyzed for SF6, CH4, CO2, and VOCs. The travel times determined for SF6 from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate transport by only gas-phase diffusion. In addition, significant concentrations of CH4 and CO2 were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF6 are caused by advective transport associated with landfill gas generation. The rates of transport varied vertically, which is attributed to multiple factors including spatial variability of water content, refuse mass, refuse permeability, and gas generation.
AB - A gas-phase tracer test (GTT) was conducted at a landfill in Tucson, AZ, to help elucidate the impact of landfill gas generation on the transport and fate of chlorinated aliphatic volatile organic contaminants (VOCs). Sulfur hexafluoride (SF6) was used as the nonreactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well and analyzed for SF6, CH4, CO2, and VOCs. The travel times determined for SF6 from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate transport by only gas-phase diffusion. In addition, significant concentrations of CH4 and CO2 were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF6 are caused by advective transport associated with landfill gas generation. The rates of transport varied vertically, which is attributed to multiple factors including spatial variability of water content, refuse mass, refuse permeability, and gas generation.
KW - Gas tracer test
KW - Gas-phase transport
KW - Landfill gas generation
KW - VOCs
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U2 - 10.1007/s11270-014-2226-0
DO - 10.1007/s11270-014-2226-0
M3 - Article
AN - SCOPUS:84913582170
SN - 0049-6979
VL - 225
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
IS - 12
M1 - 2226
ER -