Injecting air removes contaminants
The injected air is the driving force to transport contaminants to the vadose zone in air stripping. This is only effective for compounds with a suitable Henry’s constant. In some cases, soil vapour extraction is used to capture and remove contaminants from the vadose zone; in other cases, natural attenuation suffices to degrade the contaminants before they migrate to atmosphere.
Biosparging focusses on elevating groundwater oxygen concentration to above 2 mg/l, the optimum level for aerobic biodegradation.