Abstract: The blocking effect on volatile organic compounds (perchloroethylene) by different foams (produced by AC-645 or protein foaming agent) and the degradation efficiency of polycyclic aromatic hydrocarbons (PAHs) in soil by the coupling of foam and oxidant were investigated in the present study. The results showed that the foams used in this study could inhibit the volatilization of perchloroethylene and oxidize the PAHs in the soil. Among them, foam produced by AC-645 had the best blocking effect on perchloroethylene volatilization. In 3 hours, the blocking effect on perchloroethylene was maintained at about 95.0%. After 24 h, the removal rate of PAHs in soil was above 80.0%. The optimization experiment based on uniform mixing design was carried out, and it was shown that the optimal mass fraction ratio of foaming agent (AC-645), oxidant and water was 29.4%, 1.2%, 69.4%, respectively. Under this condition, the blocking rate of perchloroethylene volatilization was 94.5% within 30 min, and the removal rate of PAHs in soil was 87.8% after 24 h. Validation result showed that the bias of the experiment result and simulation prediction was 0.11%, indicating that the model prediction was accurate.

Key words: foam combined with oxidant, volatile organic compounds, blocking rate, foaming agent, perchloroethylene, polycyclic aromatic hydrocarbons (PAHs)