Residual saturation of LNAPLs in subsurface saturated zone

摘要

Laboratory-scale experiments were conducted to investigate the residual saturation of light non-aqueous phase liquids (LNAPLs) in subsurface saturated zone, which could be caused by water table fluctuation. The results show that the residual saturation of diesel in saturated zone is distinctively greater than the value in unsaturated zone, and this characteristic can be used to remove more contaminants effectively by lowering down water table and making part of residual contaminants changed into free-phase status. Contrary to the feature in unsaturated zone, where residual saturation of LNAPLs will increase with decreasing of grain size, this investigation showes that residual saturation of diesel in saturated zone decreased with decreasing of glassbeads size. In addition, the influence of water table fluctuation velocity on residual diesel saturation in saturated zone is negligible.