HR: 0800h
AN: H31A-06    [Abstracts]
TI: Nonaqueous Phase Liquid Dissolution Characteristics and Large-Scale Subsurface Contaminant Transport Modeling
AU: * Zhu, J
EM: Jianting.Zhu@dri.edu
AF: Desert Research Institute, 755 E Flamingo Road, Las Vegas, NV 89119, United States
AB: Subsurface contamination by organic chemicals in the form of nonaqueous phase liquids (NAPLs) is a widespread problem which poses a serious threat to groundwater resources. Over the last decade some significant advances have been made in determining NAPL-aqueous phase mass transfer (dissolution) characteristics. However, most of these studies have been conducted in relatively simple and homogeneous one-dimensional columns at relatively small laboratory scales. In this study, we try to determine the differences of large-scale transport characteristics using existing mass transfer rate correlations which showed very similar predictions over mass transfer rate at laboratory scales. Some of the recently developed dissolution rate coefficient correlation formulations are used to simulate the rate-limited dissolution processes. One-dimensional aqueous phase simulations are performed to examine differences among these correlations by comparing effluent concentrations. Damkohler number analysis is used to determine degree of equilibrium for each correlation and extent of error introduced by assuming local equilibrium between the NAPL and aqueous phases. Numerical models are also used to simulate two-dimensional two-phase flow and NAPL fate and transport. The simulation results illustrate the significance of the system scale on the rate of mass transfer between phases and the degree of equilibrium.
DE: 1805 Computational hydrology
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: 2007 Joint Assembly