Grantee Research Project Results

Final Report: Physics of Dissolution of Nonaqueous Phase Liquids: Pore Networks and Field Simulations

EPA Grant Number: R825689C079
Subproject: this is subproject number 079 , established and managed by the Center Director under grant R825689
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Solutions for Energy, AiR, Climate and Health Center (SEARCH)
Center Director: Bell, Michelle L.
Title: Physics of Dissolution of Nonaqueous Phase Liquids: Pore Networks and Field Simulations
Investigators: Gorelick, Steven M.
Institution: Stanford University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1995 through January 1, 1998
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management

Objective:

The objectives of this study are: (1) to contribute to the understanding of interphase mass transfer by using pore network models to investigate NAPL dissolution; (2) to analyze how the rate of dissolution varies with multiphase properties ranging from pore-scale interfacial area to measurable entities such as fluid saturation and concentration; (3) to develop a physically-based relation between dissolution rate and measurable entities that reflects dynamic processes, such as varying interfacial area, fluid saturation, and the mass fraction of soluble species; (4) to enhance a 3-dimensional multiphase compositional simulator to account for nonequilibrium NAPL dissolution, and (5) to explore the range of applicability of the local equilibrium assumption at the field scale and determine the impact of kinetically-mediated NAPL dissolution.

Summary/Accomplishments (Outputs/Outcomes):

During remediation of sites contaminated by NAPLs, immobile NAPL blobs can serve as a long-term source of contamination as the more soluble species partition into the aqueous phase. NAPL dissolution can be a rate-limited process dependent on dynamic pore- and field-scale phenomena. Few numerical models developed for hydrogeological applications exist that are multiphase, multicomponent and three-dimensional, and none of these account for rate-limited dissolution. Furthermore, in model applications involving nonequilibrium dissolution, dissolution rate coefficients are needed as input. The traditional approach has been to estimate these rates using correlation expressions developed from laboratory data. Traditional correlation expressions do not expressly account for dynamic processes, are not transferable to other data, and may not be applicable to field settings. Consequently, the validity of local equilibrium in NAPL dissolution in a realistic field setting in not well-understood.

This study involves 4 stages: (1) development of a pore network model representative of a real porous media; (2) development of a physically-based NAPL dissolution relation using the pore network model; (3) modification of a 3-dimensional compositional simulator to represent nonequilibrium NAPL dissolution, and (4) hypothetical field-scale modeling studies investigating the limitations of the local equilibrium assumption on field-scale NAPL dissolution.

This study is complete. A pore network model, consisting of a simulated 3D array of pore tubes connected by chambers, was developed to represent the physics of nonequilibrium NAPL dissolution in porous media. Two-phase flow and transport of dissolved NAPL components were represented in the network, as well as local dissolution from the NAPL phase into the surrounding water film and corners. This local dissolution was based on a solution to one-dimensional diffusion equations and is a function of the water velocity in the corner of a NAPL-filled tube or chamber. The network model successfully matches data for laboratory drainage and imbibition, and predicts experimentally determined NAPL blob-size distribution. Furthermore, simulated results of effluent solute concentration are consistent with steady-state column data. A theoretical result of general interest is the determination of a relationship between the NAPL dissolution rate coefficient and Peclet number. Four distinct regimes of this relationship were identified, representing four different physical process controlling dissolution: pore diffusion, mixing and multiple contact, corner diffusion, and a transition zone. Corner diffusion controls NAPL dissolution in the high-Peclet regime, which is characteristic of nonequilibrium NAPL dissolution. Several relationships between NAPL dissolution rate coefficient and Peclet number were generated for NAPL saturations during drainage and imbibition. These functions can be used to obtain a NAPL dissolution rate coefficients for input in a field-scale simulator for any specified Peclet number and NAPL saturation. The network model was used to investigate the relationship between interfacial area, NAPL saturation, and dissolution rate coefficients.

Journal Articles on this Report : 3 Displayed | Download in RIS Format

Publications Views

Other subproject views:	All 7 publications	3 publications in selected types	All 3 journal articles
Other center views:	All 385 publications	251 publications in selected types	All 194 journal articles

Publications

Type	Citation	Sub Project	Document Sources
Journal Article	Dillard LA, Blunt MJ. Development of a pore network simulation model to study nonaqueous phase liquid dissolution. Water Resources Research 2000;36(2):439-454.	R825689C079 (Final) R825689C080 (Final)	Abstract: Wiley - Abstract Exit
Journal Article	Dillard LA, Essaid HI, Blunt MJ. A functional relation for field-scale nonaqueous phase liquid dissolution developed using a pore network model. Journal of Contaminant Hydrology 2001;48(1-2):89-119.	R825689C079 (Final) R825689C080 (Final)	Abstract from PubMed Full-text: Science Direct - Full Text HTML Exit Abstract: Science Direct - Abstract Exit Other: Science Direct - Full Text PDF Exit
Journal Article	Zhou D, Dillard LA, Blunt MJ. A physically based model of dissolution of nonaqueous phase liquids in the saturated zone. Transport in Porous Media 2000;39(2):227-255.	R825689C079 (Final) R825689C080 (Final)	Abstract: Springer - Abstract Exit

Supplemental Keywords:

Groundwater, NAPLs, fate and transport modeling, interphase mass transfer, physics, remediation, hazardous waste, field-scale modeling studies., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Sustainable Industry/Business, Hydrology, Physics, Environmental Chemistry, Sustainable Environment, Remediation, Technology for Sustainable Environment, Fate & Transport, Hazardous Waste, Engineering, Environmental Engineering, Groundwater remediation, Hazardous, Engineering, Chemistry, & Physics, fate and transport, model, simulated aquifer pore structure, contaminants, NAPL, fate and transport , contaminant transport, interfacial areas, interfacial transport, modeling, contaminant transport model, modeling predictions, interfacial phenomena, interfacial flow, saturated porous media, mass transfer studies, pore scale determination, dissolution, dissolution dynamics, contaminated groundwater, groundwater contamination, numerical modeling, mass transfer limitations, flow and transport, NAPLs, contaminant transport models, groundwater, mass transfer rate, simulation modeling

Progress and Final Reports:

Original Abstract

1995

1996

Main Center Abstract and Reports:

R825689    Solutions for Energy, AiR, Climate and Health Center (SEARCH)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825689C001 Interactions between Electron Acceptors in the Treatment of Wastewaters Containing Sulfate, Chlorophenols and Acetate
R825689C002 Enhancing Biodegradation with Sorption and Alternating Aerobic/Anaerobic Environments
R825689C003 Development and Verification of a Numerical Model to Predict the Fate and Transport of Chlorinated Phenols in Groundwater
R825689C004 Redox Transformations of Inorganic Pollutants: Coupling to the Biogeochemical Matrix
R825689C005 Hexavalent Chromium Sorption and Desorption in Natural Soils and Subsoils
R825689C006 Biotransformation of Ordnance Wastes Using Unique Consortia of Anaerobic Bacteria
R825689C007 The Effect of Environmental Conditions on Reductive Dechlorination Rates
R825689C008 Lead Sorption, Transport, and Remediation in Natural Soils and Subsoils
R825689C009 Degradation of Chlorinated Aliphatic Compounds by Nitrifying Bacteria
R825689C010 Remediation of Contaminated Soil from the Baldock Station Maintenance Facility
R825689C011 The Effect of Apparent EH, Compound Structure, and Electron Donor on Anaerobic Biotransformation of Trinitrotoluene and its Metabolites
R825689C012 The "Bubble Wall": A Passive In Situ System for Treatment and/or Containment of Contaminated Groundwater
R825689C013 Inhibition, Inactivation and Recovery: A Universal Model for Aerobic Cometabolic Degradation of Aliphatic Compounds
R825689C014 Development, Characterization, and Performance Evaluation of Ferrous-Ferric Oxide Adsorbents for Metal Removal from Contaminated Groundwater
R825689C015 Redox Transformations of Organic and Inorganic Contaminants in the Subsurface Environment
R825689C016 Demonstration of a Permeable Barrier Technology for the Bioremediation of Ground Water Contaminated with Waste Mixtures
R825689C017 Development of a Vitamin B12-Amended Bioremediation Process for the Reductive Dechlorination of Chlorobiphenyls at all Chlorine Positions
R825689C018 An Investigation of the Chlorinated Hydrocarbon Substrate Range of the Filamentous Fungus, Graphium sp.
R825689C019 Aerobic Cometabolism of Chloroform, 1,1,1-trichloroethane, 1,1-dichloroethylene, and Other Chlorinated Aliphatic Hydrocarbons by Microbes Grown on Butane and Propane
R825689C020 Cytochrome P-450: An Emerging Catalyst for the Cometabolism of Chlorinated Aliphatic Hydrocarbons and Methyl tert-butyl Ether?
R825689C021 In-Situ Measurement of TCE Degradation Using a Single-Well "Push-Pull" Test
R825689C022 Development and Characterization of Redox Sensors for Environmental Monitoring
R825689C023 Assessing Metal Speciation in the Subsurface Environment
R825689C024 Simultaneous Removal of the Adsorbable and Electroactive Metals from Contaminated Soils and Groundwater
R825689C025 Multisolute Sorption and Transport Model for Copper, Chromium, and Arsenic Sorption on an Iron-Coated Sand, Synthetic Groundwater System
R825689C026 Development of Alkoxysilanes as Slow Release Substrates for the Anaerobic/Aerobic Transformation of Chlorinated Solvents
R825689C027 Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons by Toluene-Oxidizing Bacteria
R825689C028 Development and Characterization of Sensors and Field Instrumentation for Monitoring of Environmental Redox Conditions
R825689C029 Aerobic Cometabolism of Methyl tert-butyl Ether by Microorganisms Grown on Aliphatic Hydrocarbons
R825689C030 Biotransformation of Lead and Chromate by Bacteria
R825689C031 Magnetic Resonance Studies of Heavy Metals in Clays, Zeolites and Ceramics
R825689C032 Probing the Redox Properties of Environmental Systems: Natural Phenolic Materials
R825689C033 Reductive Dehalogenation at Carbon and Derivatized Carbon Electrodes
R825689C034 Detection of Microorganisms Capable of Anaerobic Degradation of Hazardous Substances in Natural Environments
R825689C035 Treatment of Complex Mixtures
R825689C036 Oxidation of Chlorinated Solvents by Methanotrophs
R825689C037 Detection and Assessment of Subsurface Contamination
R825689C038 Design of Reliable and Cost-Effective Mitigation Schemes
R825689C039 Gaseous Stripping of Nonaqueous Phase Liquids from the Vadose Zone
R825689C040 Anaerobic Microbial Transformation of Homocyclic and Heterocyclic Polynuclear Aromatic Hydrocarbons
R825689C041 Effects of Sorption on Biodegradation of Halogenated Organics
R825689C042 Trace Metal Removal Processes
R825689C043 FASTCHEM Applications and Sensitivity Analysis
R825689C044 Long-term Chemical Transformation of 1,1,1-Trichloroethane (TCA) and Freon 113 under Aquifer Conditions
R825689C045 In-Situ Anaerobic Biological Treatment of Aromatics in Groundwater
R825689C046 Use of Starvation and Stress Promoters for Biodegradation of Hazardous Wastes
R825689C047 Determining and Modeling Diffusion-Limited Sorption and Desorption Rates of Organic Contaminants in Heterogeneous Soils
R825689C048 Dispersion Modeling of Volatile Organic Emissions from Ground-Level Treatment Systems
R825689C049 Subsurface Mixing of Nutrients and Groundwater for in-Situ Bioremediation
R825689C050 Test-Bed Evaluation of In-Situ Bioremediation of Chlorinated Aliphatic Compounds by Toluene Oxygenase Microorganisms
R825689C051 Demonstration of in-Situ Bioremediation of Chlorinated Aliphatics by Methanotrophs at St. Joseph
R825689C052 Aquifer Remediation Design in the Presence of Kinetic Limitations
R825689C053 Determination of Macroscopic Transport Parameters for Biologically Reacting Solutes in Aquifers
R825689C054 Transformation of Chlorinated Hydrocarbons by Reduced Metallocoenzymes--Kinetic Model Development and Applications to Environmental Systems
R825689C055 Microbial Degradation of Toluene Under Sulfate-Reducing Conditions--The Role of Iron
R825689C056 Transformation of TCE by Methanotrophic Biofilms
R825689C057 Heavy Metals in Ceramic Matrix: Heavy Metals/Clay Interactions in Ceramic Processing
R825689C058 Radon-222 Method for Locating and Quantifying Contamination by Residual Non-Aqueous Phase Liquids in the Subsurface
R825689C059 Process Submodel Formulation and Parameter Estimation for Simulation of Bioremediation
R825689C060 Enhancement of Biodegradation through the Use of Substituted Porphyrins to Treat Groundwater Contaminated with Halogenated Aliphatics
R825689C061 Field Test of In-Situ Vapor Stripping for Removal of VOCS from Groundwater
R825689C062 System Design for Enhanced In-Situ Biotransformation of Carbon Tetrachloride: Application to DOE's Arid Site Integrated Demonstration
R825689C063 Modeling Strategies for Optimizing In-Situ Bioremediation
R825689C064 Anaerobic Treatment of Chlorinated Solvent Contaminated Groundwater
R825689C065 In Situ Treatment of Chlorinated Solvents
R825689C066 Moffett Field In-Situ Bioremediation Study in Support of Full Scale Application
R825689C067 Full-Scale Evaluation of In Situ Bioremediation of Chlorinated Solvent Groundwater Contamination
R825689C068 Upscaling Pore-Scale Hydrodynamics and the Transport of Reactive Solutes
R825689C069 Pathways of Anaerobic Toluene Metabolism by a Sulfate-Reducing Bacterium, Strain PRTOL1
R825689C070 Anaerobic Ethylbenzene Oxidation in Denitrifying Strain EB1
R825689C071 Molecular Approaches to Optimize Starvation Promoter Dricen TCE Bioremediation in Pseudomonas
R825689C072 Modeling VOC Emissions from Hazardous Waste Sites
R825689C073 Reductive Transformation of Chlorinated Hydrocarbons by Reduced Ethenes Catalyzed by Vitamin B12 - Mechanistic and Kinetic Studies
R825689C074 Evaluation of Strategies for Full Scale Bioremediation of the Seal Beach Site Using Anaerobic Microbial Processes
R825689C075 Trace Element Adsorption in Porous Particle Packed Beds
R825689C076 Hydrologic and Biological Factors Affecting Aquifer Clogging During In-Situ Bioremediation
R825689C077 Full-Scale Evaluation of an Apparatus for Down-well Oxygen Transfer to Implement In situ Bioremediation at Edwards AFB
R825689C078 Field Testing of Palladium-Catalyzed Hydrodehalogenation for Chlorinated Hydrocarbon Removal from Groundwater
R825689C079 Physics of Dissolution of Nonaqueous Phase Liquids: Pore Networks and Field Simulations
R825689C080 Three-Phase Flow in Fractured Media
R825689C081 Effects of Redox Zones on the Fate and Transport of Contaminants in the Saturated Subsurface; Characterization and Simulation
R825689C082 Biochemical Mechanisms of PCE Dehalogenation by Strain MS-1, and its Potential for In-situ Bioaugmentation
R825689C083 A Large Scale Model for Anaerobic Bioremediation at the Seal Beach Site
R825689C084 Mechanisms, Chemistry, and Kinetics of Anaerobic Degradation of cDCE and Vinyl Chloride
R825689C085 Bioenhanced In-Well Vapor Stripping to Treat Trichloroethylene (TCE)
R825689C086 Effect of Chemical Structure on the Biodegradability of Halogenated Hydro-carbons
R825689C087 Trace Element Adsorption in Porous Particle Packed Beds
R825689C088 Arsenic Removal in High Capacity Porous Alumina Packed-Bed Reactors
R825689C089 Measurement of Interfacial Areas and Mass Transfer Coefficients Between Residual PCE and Water During Surfactant Enhanced Aquifer Remediation
R825689C090 Proof of Gene Expression During Bioaugmentation
R825689C091 Experimental and Mathematical Study of Biomass Growth in Pore Networks and its Consequences in Bioremediation
R825689C092 Gene probes for detecting anaerobic alkylbenzene-degrading bacteria
R825689C093 Investigation of Palladium Catalyzed Hydrodehalogenation for the Removal of Chlorinated Groundwater Contaminants: Surface Chemistry of Catalyst Deactivation and Regeneration
R825689C094 Aerobic Methanotrophic Transformation of Biphenyl, Monochlorobiphenyls, and Dichlorobiphenyls