中文摘要：

通过增溶实验和土壤洗脱实验,研究了一种生物表面活性剂——皂角苷（saponin）对多环芳烃-重金属复合污染土壤的洗脱作用及机理。结果表明,皂角苷对菲、芘等多环芳烃有极强的增溶作用,当皂角苷浓度为0.04%时,菲、芘在液相中的表观溶解度分别增大了约22倍和128倍,因而皂角苷能显著增强多环芳烃污染土壤中菲、芘的洗脱,洗脱效率最大分别可达84.1%和81.4%,增大了约2倍和17倍。皂角苷可与重金属离子形成水溶性的络合物,从而增强洗脱重金属污染土壤中的Zn^2＋和Cd^2＋,在皂角苷浓度为0.4%时,Zn^2＋、Cd^2＋的洗脱效率分别可达93.0%和79.4%,增大了约75倍和8倍。皂角苷可同时洗脱多环芳烃-重金属复合污染土壤中的菲、芘和Zn^2＋、Cd^2＋,洗脱效率分别达87.6%、83.5%和92.3%、78.6%,重金属的存在略增大了皂角苷对菲、芘等多环芳烃的洗脱效率,但多环芳烃对Zn^2＋、Cd^2＋的洗脱效率没有明显影响。皂角苷可同时增强洗脱复合污染土壤中的多环芳烃和重金属,从而为多环芳烃-重金属复合污染土壤的修复奠定基础。

英文摘要：

Biosurfactants have great advantages in the remediation of organic contaminated soils as their environmental friendly nature. The performance of saponin,a plant-derived biosurfactant,for the removal of polycyclic aromatic hydrocatbons（PAHs） and heavy metal from co-contaminated soils were studied. The results indicated that saponin can greatly enhance the solubilization of phenanthrene and pyrene in solution by the partition of them into saponin micelle and then the removal of phenanthrene and pyrene from PAHs-contaminated soil. The maximum removal rates of 84.1% and 81.4% were obtained for phenanthrene and pyrene from PAHs-contaminated soil,respectively. Saponin could form complex compound with heavy metals by the external carboxyl groups,which greatly enhanced the removal of zinc and cadmium from heavy metal contaminated soil and the removal rates of 93.0% and 79.6% were obtained for zinc and cadmium with a sapoin concentration of 0.4%,respectively. For the co-contaminated soil with PAHs and heavy metals,87.6% of phenanthrene,83.5% of pyrene,92.3% of zinc and 78.6% of cadmium were simultaneously removed by saponin at a concentration of 0.4%. The removal rates of zinc and cadmium from co-contaminated soil did not show obvious difference with the presence of PAHs,but the addition of heavy metals slightly enhanced the removal of phenanthrne and pyrene from the co-contaminated soil. Thus,saponin had the potential capability to simultaneously remove PAHs and heavy metal from the co-contaminated soils.