Grantee Research Project Results
Final Report: Dissolution Kinetics of Single and Multicomponent NAPL Pools in Saturated Three-dimensional Porous Media
EPA Grant Number: R823579Title: Dissolution Kinetics of Single and Multicomponent NAPL Pools in Saturated Three-dimensional Porous Media
Investigators: Chrysikopoulos, Constantinos V.
Institution: University of California - Irvine
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 1995 through August 1, 1998
Project Amount: $315,368
RFA: Exploratory Research - Chemistry and Physics of Water (1995) RFA Text | Recipients Lists
Research Category: Water , Safer Chemicals , Land and Waste Management
Objective:
The objective of this research is to study the dissolution of single and multicomponent nonaqueous phase liquid (NAPL) pools in three-dimensional experimental aquifers.Summary/Accomplishments (Outputs/Outcomes):
The contamination of groundwater and subsurface systems by dense, nonaqueous phase liquids (DNAPLs), typically chlorinated organic solvents, is one of the most common groundwater quality problems in the United States and other industrialized nations. These liquids infiltrate into the subsurface via leaks and spills and, if their volume is sufficient, penetrate into groundwater. Along the percolation pathway, portions of DNAPLs become entrapped by capillary forces, and are commonly referred to as residual ganglia or blobs. The front of the spill will continue to penetrate the subsurface until it encounters a semi-permeable geologic unit. There it will deflect horizontally, forming a relatively flat pool. As stationary residual and pooled DNAPL, these solvents serve as dissolving sources, capable of degrading the water quality of large aquifers. Experience has shown that DNAPL can persist for decades in the natural subsurface because it is sparingly soluble (solubility typically on the order of a few g/L or less), and because of mass transfer limitations associated with the dissolution of a liquid in a porous medium.The proposed emphasis of this study was to undertake experimental and theoretical investigations to elucidate our understanding of the dissolution of single and multicomponent DNAPL pools in groundwater systems. More specifically, a theoretical framework, or model, for the pool dissolution hydrodynamics was presented and experimental systems were proposed by which to generate data with which to test the proposed model. The study of pool dissolution, unlike many of the residual dissolution studies that have been completed, requires a three-dimensional approach. Our focus on pools was for two reasons: (1) there is a relative sparsity of pool data in the literature compared to that for residuals, and (2) surface area to DNAPL volume considerations suggest that pooled DNAPL may persist longer in the environment than residual DNAPL.
The following objectives were achieved:
Experimental quantification of the dissolution of single-component DNAPL pools in intermediate scale representations of three-dimensional model aquifers over a range of groundwater flow rates.
Development of a three-dimensional mathematical model describing single component DNAPL dissolution from idealized pool configurations (rectangular, elliptic/circular) in a homogeneous aquifer under unidirectional flow conditions.
Verification/calibration of the single-component model from comparison of model simulations with controlled three-dimensional dissolution experiments.
Extension of the three-dimensional mathematical model to yield a model simulating the dissolution of multi-component DNAPL pools.
The final report is organized in a series of self-contained chapters. Chapter 1 summarizes the results of a literature review regarding classical mass transfer and dissolution studies, as well as environmentally based residual and pooled NAPL dissolution studies. Its purpose is to provide a context for the present work, and to identify critical directions for follow-up investigations. Chapter 2 presents a theoretical investigation of NAPL pool dissolution in stratified and anisotropic formations. Chapter 3 introduces a semi-analytical mathematical model for contaminant transport resulting from the more general case of multi-component NAPL pool dissolution. Chapters 4 and 5 provide a comprehensive development of the underlying theory and accompanying mathematical framework hypothesized to explain single-component DNAPL pool dissolution behavior. Furthermore, theoretically based pool-averaged and local mass transfer correlations for particular pool shapes are provided. The experimental contributions of this study are then summarized in Chapters 6 and 7. In Chapter 6, plumes emanating from controlled, ideally placed pools are presented and compared with model-simulated results. In Chapter 7, a parallel set of results is presented for non-ideally placed pools.
Journal Articles on this Report : 9 Displayed | Download in RIS Format
| Other project views: | All 22 publications | 9 publications in selected types | All 9 journal articles |
|---|
| Type | Citation | ||
|---|---|---|---|
|
|
Chrysikopoulos CV, Lee KY. Contaminant transport resulting from multicomponent nonaqueous phase liquid pool dissolution in three-dimensional subsurface formations. Journal of Contaminant Hydrology, May 1998;31(1-2):1-21. |
R823579 (1998) R823579 (Final) |
not available |
|
|
Chrysikopoulos CV, Kim TJ. Local mass transfer correlations for nonaqueous phase liquid pool dissolution in saturated porous media. Transport in Porous Media 2000;38(1-2):167-187. |
R823579 (1998) R823579 (Final) |
not available |
|
|
Chrysikopoulos CV, Lee KY, Harmon TC. Dissolution of a well-defined trichloroethylene pool in saturated porous media: Experimental results and model simulations. Water Resources Research 2002,36(15):3911-3918. |
R823579 (Final) |
not available |
|
|
Harmon TC, Kim TJ, Dela Barre BK, Chrysikopoulos CV. Cosolvent-water displacement in one-dimensional soil column. Journal of Environmental Engineering-Asce 1999;125(1):87-91. |
R823579 (1998) R823579 (Final) |
not available |
|
|
Khachikian C, Harmon TC. Nonaqueous phase liquid dissolution in porous media: Current state of knowledge and research needs. Transport in Porous Media 2000;38(1-2):3-28. |
R823579 (Final) |
not available |
|
|
Kim TJ, Chrysikopoulos CV. Mass transfer correlations for nonaqueous phase liquid pool dissolution in saturated porous media. Water Resources Research 1999;35(2):449-459. |
R823579 (Final) |
not available |
|
|
Lee KY, Chrysikopoulos CV. Numerical modeling of 3-dimensional contaminant migration from dissolution of multicomponent NAPL pools in saturated porous media. Environmental Geology 1995;26(3):157-165. |
R823579 (Final) |
not available |
|
|
Lee KY, Chrysikopoulos CV. NAPL pool dissolution in stratified and anisotropic porous formations. Journal of Environmental Engineering-Asce 1998;124(9):851-862. |
R823579 (1998) R823579 (Final) |
not available |
|
|
Tatalovich ME, Lee KY, Chrysikopoulos CV. Modeling the transport of contaminants originating from the dissolution of DNAPL pools in aquifers in the presence of dissolved humic substances. Transport in Porous Media 2000;38(1-2):93-115. |
R823579 (Final) |
not available |
Supplemental Keywords:
Scientific Discipline, Water, Waste, Remediation, Engineering, Chemistry, Environmental Chemistry, Engineering, Chemistry, & Physics, Groundwater remediation, Physics, chemical transport modeling, aquifer remediation design, plume dispersion models, multicomponent NAPL pools, three dimensional porous media, groundwater contamination, chemical kineticsProgress 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.