Experimental and numerical research on migration of LNAPL contaminants in fractured porous media

The contamination of groundwater by organic compounds is becoming more common and severe. A diesel tracer, a light non-aqueous phase liquid (LNAPL), was selected to carry out experiments of contaminant migration in fractured porous media. At the same time, trials of contaminant remediation methods were conducted using distilled water. The experimental results showed that the dominant flow was more obvious in fractured porous media than in porous media owing to the effect of the fractures on contaminant migration. The mechanism of contaminant migration and remediation was revealed by the movement of oil-driven air and water-driven oil. The dispersion parameters of these media were calibrated through the calculated areas and the measured contamination and remediation areas, using a numerical method. The predicted results indicate that the greater the injection rate, the shorter the time to penetrate the fractured porous media. However, relative to the LNAPL migration experiments, the water-driven oil processes were slower and the remediation time was longer at the same injection rate.