随着城市化和工业化的不断推进，污染土壤修复逐渐成为国内外环境领域研究者关注的热点问题。基于药剂的土壤修复方法都面临一个共同的挑战：如何顺利地将药剂输送至目标修复区域，尤其是在非均质土壤中。本研究以提高纳米零价铁（nZVI）在多孔介质中的迁移性为目的，在实验室水平上分别进行了泡沫静态特征及对nZVI携带能力的研究、不同载体（水、表面活性剂溶液、泡沫）携带下nZVI在多孔介质中迁移性探究、以及泡沫作为载体时，nZVI对污染土壤中DDT的去除效率研究及作用机制分析，主要结论如下： 1. 通过考察4种不同表面洗性剂SDS、SLES、SDBS、TX-100的泡沫的静态特征及其对nZVI携带能力的实验探究，综合考虑发泡能力、泡沫稳定性以及泡沫对纳米铁的携带能力，最终选取SLES为最佳发泡剂，最佳发泡浓度为2.5 g/L，泡沫质量为93%。 2. 由三种载体对nZVI的携带迁移能力实验结果的对比分析得出：表面活性剂泡沫 > 表面活性剂溶液 > 水。大孔隙介质更有利于nZVI的迁移，泡沫携带nZVI在粗砂中的残留率为32％，仅为细砂残留率（63％）的一半，但在粗砂中，泡沫相对于溶液对nZVI迁移提升作用为6%，在细砂中的提升效果为209%，泡沫在细砂介质中孔隙流速大，对nZVI的拖曳力更大，所以泡沫作为载体在细砂中的优势更为显著。 3. DDT去除实验的结果表明：泡沫作为载体对DDT的去除效率远高于溶液作为载体。泡沫和溶液分别作为载体时，粗砂介质中DDT的去除率为99%和69%，细砂介质中DDT去除率分别为60%和26%。在相同的实验条件下，较高的发泡剂浓度更有利于DDT的去除，当发泡剂浓度为5 g/L 时，DDT的去除效率可以达到75％，而发泡液浓度降至1 g/L时，去除率仅为44%。当发泡剂浓度高于临界胶束浓度时，表面活性剂种类对DDT总体去除效率影响很小（DDT的总去除率：SLES：76%，SDS：78%，TX-100：72%）。 4. 泡沫-nZVI作为污染土壤的冲洗液时，对DDT去除的三种作用机制及其贡献值排序为：还原反应作用（44.2％）> 增溶作用（34.8％）> 提高波及效率作用（21％）

With the continuous development of urbanization and industrialization, contaminated soil remediation has gradually become a hot issue for researchers in the environmental field at home and abroad. Soil remediation methods using agents all face a common challenge: how to successfully deliver the agent to the target area, especially in the heterogeneous soil. The purpose of this study was to improve the migration of nano-zero-valent iron (nZVI) in porous media. At the laboratory level, the static characteristics of the foam and carrying capacity for nZVI were studied. And the migration of nZVI with different carriers (water, surfactant solution, foam) was also investigated in porous media. Then the author explored the removal efficiency of DDT in contaminated soils and analyzed the mechanismthes when foam was used as a carrier for nZVI. The main conclusions are as follows: 1. The investigation of foam’s static characteristics and carrying capacity of four surfactant (SDS、SLES、SDBS、TX-100) for nZVI showed that SLES was the best choice as a foaming agent after considering the foaming capacity, foam stability and the carrying capacity. Foaming concentration was 2.5 g/L, foam quality was 93%. 2. The experimental results showed that the carrying capacity of the three carriers for nZVI migration followed: Surfactant foam > Surfactant solution > Water. The macroporosity medium was more conducive to the migration of nZVI. The residual rate of nZVI carried by foam in coarse sand was 32%, which was only half of the residual rate of fine sand (63%). The migration of nZVI with foam as carrier was improved 6% relative to solution as carrier in coarse sand. However, the improvent was 209% in fine sand. The foam had a larger velocity in the fine sand medium with a certain flow, and it would produce a greater drag force on nZVI. Therefore, the advantage of foam as a carrier in fine sand was more remarkable. 3. The results of DDT removal experiments showed that total removal efficiency of DDT when foam as the carrier for nZVI was much higher than that of solution as carrier. The DDT removal efficiencies were 99% and 69% in coarse sand when foam and solution were used as carrier, respectively. And the DDT removal efficiencies in fine sand medium were 60% and 26% with foam and solution used as carrier, respectively. Under the same experimental conditions, the higher surfactant concentration was more conducive to the removal of DDT. When the SLES concentration was 5 g/L, the DDT removal efficiency could reach 75%. When the concentration of SLES was decreased to 1 g/L, the removal efficiency was only 44%. When the surfactant concentration was higher than the critical micelle concentration, the surfactant species had little effect on the removal efficiency of DDT (total removal of DDT: 76% for SLES, 78% for SDS, and 72% for TX-100). 4. When foam-nZVI was used as the fluid for contaminated soil, three mechanisms contributed to DDT removal. The contributing mechanisms were ranked as follows under the experimental conditions: reduction reaction (44.2%) > solubilization (34.8%) > increased sweep efficiency (21%).