Grantee Research Project Results
1999 Progress Report: Partitioning Tracers for In-Situ Detection and Measurement of Nonaqueous Phase Liquids in Porous Media
EPA Grant Number: R825407Title: Partitioning Tracers for In-Situ Detection and Measurement of Nonaqueous Phase Liquids in Porous Media
Investigators: Brusseau, Mark
Institution: University of Arizona
EPA Project Officer: Hahn, Intaek
Project Period: November 1, 1996 through October 31, 1999
Project Period Covered by this Report: November 1, 1998 through October 31, 1999
Project Amount: $246,339
RFA: Environmental Fate and Treatment of Toxics and Hazardous Wastes (1996) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management , Safer Chemicals
Objective:
The overall goal of the proposed project is to explore the use of partitioning tracers to characterize nonaqueous phase liquids (NAPLs) (particularly LNAPLs) in aquifer systems. We are specifically focused on the effects of mass transfer rate limitations and of porous-media heterogeneity on the efficacy of partitioning tracers.Progress Summary:
We have made progress along several fronts, as outlined below.- Analysis of the influence of biodegradation, heterogeneity, and mass transfer on efficacy of the partitioning tracer method: we have conducted detailed analyses of data sets collected from previous field-scale partitioning tracer tests. As part of this analyses, we have examined the impact of porous-media heterogeneity, liquid-liquid mass transfer, and biodegradation on the performance of the method. For example, in this method, NAPL saturation is obtained by calculating a retardation factor for a partitioning tracer used in conjunction with a nonreactive tracer. The retardation factor for a partitioning tracer is usually determined by calculating the quotient of the travel times measured for the partitioning and nonpartitioning tracers. Our results show that biodegradation of the partitioning tracer can reduce the magnitude of its calculated travel time, which results in an underestimation of the retardation factor, and thus of NAPL saturation. This work has resulted in two manuscripts currently in press (see below), and one in preparation
- Development of mathematical models: we have developing "advanced" mathematical models to describe the transport of tracers in heterogeneous systems. The model explicitly incorporates multiple mass-transfer processes at multiple scales. One manuscript is currently in press and one is in preparation based on this work.
- We have recently completed a set of experiments designed to examine the efficacy of the partitioning tracer method for measuring NAPL saturation associated with "pool" systems. We are currently analyzing the results and preparing a manuscript.
- The research discussed above involves aqueous-phase tracer tests conducted in water-saturated systems. We also are evaluating the use of gas-phase partitioning tracer tests for measuring NAPL saturation in the vadose zone. We have conducted a series of pilot-scale field tests at a hydrocarbon-contaminated site, and are currently completing analysis. One manuscript will be produced based on this research.
Future Activities:
Effective risk assessment and remediation of NAPL-contaminated sites is limited by current site characterization techniques. This research project involves an integrated approach for the testing of a new, promising method for characterizing NAPLs in subsurface systems. The efficacy of this new method must be evaluated under a variety of conditions before it can be applied with complete confidence to real problems. Specifically, the influence of potential constraining factors on its performance must be elucidated. The results of our project research are contributing to the resolution of these issues. We plan to continue to pursue the focal points identified above.Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 7 publications | 3 publications in selected types | All 3 journal articles |
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Type | Citation | ||
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Cain RB, Johnson GR, McCray JE, Blanford WJ, Brusseau ML. Partitioning tracer tests for evaluating remediation performance. Ground Water 2000;38(5):752-761. |
R825407 (1998) R825407 (1999) R825407 (Final) |
not available |
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Li Z, Brusseau ML. Nonideal transport of reactive solutes in heterogeneous porous media 6. Microscopic and macroscopic approaches for incorporating heterogeneous rate-limited mass transfer. Water Resources Research 2000;36(10):2853-2867. |
R825407 (1998) R825407 (1999) R825407 (Final) |
not available |
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Nelson NT, Oostrom M, Wietsma TW, Brusseau ML. Partitioning tracer method for the In Situ measurement of DNAPL saturation: influence of heterogeneity and sampling method. Environmental Science & Technology 1999;33(22):4046-4053. |
R825407 (1998) R825407 (1999) R825407 (Final) |
Exit Exit |
Supplemental Keywords:
groundwater, soil, chemical transport, risk assessment, chemicals, solvents, NAPL, remediation, cleanup, hydrology, measurement methods., RFA, Scientific Discipline, Waste, Ecosystem Protection/Environmental Exposure & Risk, Health Risk Assessment, Environmental Chemistry, Remediation, Chemistry, Fate & Transport, Hazardous Waste, Hazardous, hazardous waste treatment, fate and transport, oils spills, fate and transport , NAPL, contaminant transport, risk characterization, chemical speciation, transport contaminants, partitioning tracers, adverse human health affects, chemical contaminants, ecological impacts, hazardous chemicals, porous media, contaminant transport models, restoration planningProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.