抄録
The conventional vapor extraction technique for soil remediation is fairly effective for the clean-up of unsaturated soil. However, it is difficult to apply this technique to general contaminated sites in Japan where the groundwater level is very high. To solve this problem, the two-phase extraction technique has been developed. In this paper, this technique was applied to a contaminated site and proved fairly effect. Moreover, a prediction analysis of clean-up efficiency is carried out and prediction results are compared with the field data. The analysis model is a simple macro-scopic model, and thermodynamic equibilium states are assumed in the formulation. The two-phase extraction technique is effective in a shallow aquifer and recovery mass from vapor is 5 to 10 times larger than that from groundwater. In addition, surface gas concentrations after remediation are 90% lower than before remediation. The prediction analysis needs quite a large correction factor because this analysis assumed a homogeneous concentration distribution. However, this analysis is effective for rough estimates and is a simple to use.
