Field-scale model for air sparging performance assessment and design

Air sparging has been used as an in situ technique to remove VOCs from contaminated groundwater: air is injected into the groundwater from an injection well, and the VOC partitions into the air phase and rises to the unsaturated zone, where another technique, such as soil vapor extraction, is used to remove the gases from the vadose zone. A computer model that accurately describes the process is needed. This project comprises model development and laboratory experiments, conducted independently. The model will be tested using the laboratory data. Only preliminary results are available. Preliminary laboratory column tests have been conducted along with some modeling to simulate the removal of a single VOC from a soil column. Comparison show that a finite element code is able to predict removal of methane and TCE. To determine if the air flow pattern in air sparging is predictable, experiments were done in a large-scale reactor and compared to numerical simulations.