Pore Scale Study of Nonaqueous Phase Liquids Transport and Dissolution in GroundwaterEPA Grant Number: F5A20151
Title: Pore Scale Study of Nonaqueous Phase Liquids Transport and Dissolution in Groundwater
Investigators: Liu, Elizabeth B
Institution: The Johns Hopkins University
EPA Project Officer: Jones, Brandon
Project Period: January 1, 2005 through December 1, 2006
Project Amount: $111,172
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Nonaqueous phase liquids (NAPLs), such as oils, gasoline, and chlorinated solvents, are sources of common and persistent groundwater contaminations. Due to the complexity and heterogeneity of the subsurface porous media, many aspects of the fate and transport of NAPL contaminants are still unknown. To better understand NAPL flow and transport in groundwater, a good fundamental understanding of NAPL processes at the pore scale is needed. The goal of this research is to gain a better understanding of multiphase pore-scale processes by studying how different parameters such as wettability, anisotropy, and mass transfer characteristics affect the migration and dissolution of NAPLs in the subsurface. In particular, we will use a powerful numerical approach known as Lattice Boltmann (LB) modeling to study how interfacial areas, blob shrinkage, and contact angle affect NAPL migration and dissolution in groundwater.
To accomplish this goal, a combination of experimental and computational techniques will be used. Detailed X-ray images of multiphase porous medium systems consisting of a pollutant infiltrating water saturated porous media will be obtained using Synchrotron X-ray microtomography. These images will provide detailed information relating the pore structure of the system to the observed fluid flow. These pore morphological structures will then be used in numerical simulations to accurately model various aspects of multiphase flow. The numerical approach used in this research is called Lattice Boltzmann modeling, which has been shown to be well suited for studies with porous media. The results of the LB simulations will be compared with our experimental results and also with other experimental data provided by another group. These comparisons will provide excellent opportunities to validate and calibrate our model and to allow the model to be used for upscaling purposes.
The proposed experiments will produce a set of real pore morphological structures that can be used to construct realistic simulations. These results will produce a dataset of residual NAPL characteristics that will prove valuable to engineers trying to develop better models for remediation planning. We believe this work will advance our understanding of the flow and entrapment of NAPLs in the subsurface. These advances are essential to interpretation and model development of complex systems at larger scales for remediation of groundwater contamination.