| Groundwater is one of the nation's most important natural resources, composing a large portion of total freshwater on earth. Therefore, groundwater contamination is a growing concern among groundwater hydrologists and the general public. Organic contaminants, often present as non-aqueous phase liquid (NAPL) in the groundwater, are major groundwater contaminants of concern. The purpose of this work was to investigate the mobilization of entrapped disconnected NAPL in porous medium systems. Tetrachloroethylene (PCE) was chosen as a model NAPL compound. Fluid properties of PCE were analyzed and column experiments as well as lattice Boltzmann simulations were performed to determine the relationships between residual NAPL saturation, fluid properties, and viscous forces. Trapping number (NT) was tested as a criterion to predict and validate residual NAPL mobilization in porous media. Residual saturation was found to decrease with increasing viscous forces and NT. The experimental data and simulation results were compared and showed good agreement. |
