Grantee Research Project Results
2001 Progress Report: Dissolution Dynamics of Multiple Component NAPLs In Aqueous and Surfactant/Cosolvent Systems
EPA Grant Number: R827112Title: Dissolution Dynamics of Multiple Component NAPLs In Aqueous and Surfactant/Cosolvent Systems
Investigators: Brusseau, Mark
Institution: University of Arizona
EPA Project Officer: Aja, Hayley
Project Period: September 1, 1998 through August 31, 2001 (Extended to December 20, 2002)
Project Period Covered by this Report: September 1, 2000 through August 31, 2001
Project Amount: $362,453
RFA: Exploratory Research - Physics (1998) RFA Text | Recipients Lists
Research Category: Land and Waste Management , Air , Safer Chemicals
Objective:
The objective of this research project is to enhance understanding of the dissolution of non-ideal, multiple-component, nonaqueous phase (immiscible) organic liquids (NAPLs) in subsurface systems. Additional objectives are to investigate: (1) the effect of NAPL composition-dependent factors on dissolution of multiple-component NAPLs in groundwater; (2) the effect of NAPL mass-transfer limitations on dissolution of multiple-component NAPLs in groundwater; and (3) the effect of NAPL composition and mass-transfer limitations on the enhanced dissolution of multiple-component NAPLs caused by solubilization agents.Progress Summary:
Progress has been made along several fronts. The investigators have concluded a series of batch experiments investigating the ideality of dissolution behavior measured for a multiple-component NAPL system containing either water or a surfactant. This work was noted in last year's report and the results have been published in a peer-reviewed journal. An initial series of column experiments designed to examine multiple-component NAPL dissolution behavior under dynamic flow conditions has been completed. Experiments for the same three component NAPL system described aboveusing water, biosurfactant, and cyclodextrin solution, also have been completed. The results of this work are in current preparation for submission to a peer-reviewed journal.The investigators are continuing a series of column experiments examining the influence of sorption/desorption on low-concentration elution tailing versus the impact of immiscible-liquid dissolution processes. Low-concentration elution tailing often is observed at contaminated field sites. A major question of interest is: What process (or group of processes) is causing this behavior? Various mass-transfer limitations associated with NAPL dissolution (local-scale mass transfer, heterogeneity-related factors) may contribute to tailing. In addition, rate-limited desorption from the "soil solids" may contribute to observed tailing. Thus, it is important to differentiate the impacts of these various processes. However, low-concentration elution behavior rarely is studied in laboratory experiments. Experiments have been conducted to examine the elution tailing behavior of naphthalene, a compound common to many multiple-component NAPLs, and trichloroethene, a common chlorinated-solvent compound, in aqueous solutions flowing through columns packed with porous media. The results of this work have been translated to a manuscript currently in review. Experiments are being conducted to examine the low-concentration elution behavior associated with water flowing through columns packed with porous media containing a residual phase of immiscible-liquid contamination. The experiments are being conducted using several porous media, each with a different magnitude of sorption potential for the target compounds.
The investigators are continuing to develop and apply mathematical models to describe NAPL dissolution and component transport. A manuscript currently is in preparation, wherein work that couples descriptions of NAPL dissolution and sorption/desorption dynamics will be presented.
Future Activities:
Effective risk assessment and remediation of NAPL-contaminated sites is limited by the current lack of understanding regarding the dissolution behavior of multiple-component NAPLs. The results of this research project will contribute to the resolution of these issues. The investigators plan to continue to pursue the focal points identified above.Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 11 publications | 2 publications in selected types | All 2 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
McCray JE, Bai GY, Maier RM, Brusseau ML. Biosurfactant-enhanced solubilization of NAPL mixtures. Journal of Contaminant Hydrology 2001;48(1-2):45-68. |
R827112 (2000) R827112 (2001) R827112 (Final) |
not available |
Supplemental Keywords:
groundwater, soil, chemical transport, risk assessment, chemicals, solvents, NAPL, remediation., RFA, Scientific Discipline, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Physics, Remediation, Environmental Chemistry, Restoration, State, chemical mixtures, Aquatic Ecosystem Restoration, Groundwater remediation, Engineering, Chemistry, & Physics, groundwater recharge, NAPL, aquifer flushing, Utah (UT), mass transfer, dissolution dynamics, aquifer remediation design, alternative cleanup standards, soil and groudwater remediation, aquatic ecosystems, groundwater contamination, surfactants, cosolvent systems, NAPLsProgress 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.