泡沫阻断协同氧化修复土壤中四氯乙烯和多环芳烃

Remediation of perchloroethylene and polycyclic aromatic hydrocarbons contaminated soil by foam-blocking coupled with oxidants

研究了不同发泡剂(AC-645或蛋白类发泡剂)产生的泡沫对四氯乙烯挥发的阻断效果,以及发泡剂与氧化剂耦合后产生的泡沫对土壤中多环芳烃的氧化去除效果。结果表明,本研究所用泡沫材料既可以抑制四氯乙烯的挥发逸散,又可以氧化去除土壤中的多环芳烃,其中以AC-645发泡材料对四氯乙烯挥发的阻断效果最优,在3h内对四氯乙烯的阻断效果可维持在95.0%左右,反应24h后对土壤中多环芳烃的去除率在80.0%以上。混料均匀设计试验发现,最优配比下发泡剂(AC-645)、氧化剂和水的质量分数分别为29.4%、1.2%、69.4%,该配比的泡沫耦合氧化剂修复材料产生的泡沫在30min时对四氯乙烯的阻断率为94.5%,反应24h后对土壤中多环芳烃的去除率在87.8%。在最优点处进行验证试验,验证值与预测值的相对偏差为0.11%,表明模型预测准确。

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.