Abstract

Seven surfactants were selected as candidate agents for in situ soil column flushing. Column flushing lacks the interaction between surfactants and contaminants, so efficiency is not easy to improve. Microbubbles generated in situ may adhere to the contaminant diesel. Thereafter, the bubbles were mobilized to lift the multi-system oil to the top layer. This process must be attributed to the increased column flushing efficiency of diesel removal. Compared with a single solution, using randomly methylated beta-cyclodextrin (RAMEB) and microbubble enhancement, the diesel removal of column flushing increased by 30.7%. Compared with the existing conditions (5.25 × 10⁻⁴cm s⁻¹), the hydraulic conductivity of loam soil (3.74 × 10⁻³cm s⁻¹) increased by 7.1 times after the continued operation of the two processes. The oil layer was collected for further reuse. After three treatments, the effluent for the RAMEB was more than 85%. The collected effluent was treated with a synthetic absorbent and then qualifiedly discharged with a TOC value of only 2.6 mg L⁻¹. By combining surfactant flushing with microbubbles and other equipment, not only can the reaction time be effectively saved, but organic pollutants could be concentrated and reused in the soil, so no additional treatment was required.

摘要

选择了七种表面活性剂作为原位土壤柱冲洗的候选试剂。色谱柱冲洗缺少表面活性​​剂与污染物之间的相互作用，因此效率不易提高。原位产生的微气泡可能会附着在污染物柴油上。之后，气泡被移动以将多系统油提升至顶层。该过程必须归因于提高的柴油去除塔冲洗效率。与单一溶液相比，使用随机甲基化的β-环糊精（RAMEB）和微泡增强，柱冲洗的柴油去除量增加了30.7％。与现有条件（5.25×10 ^-4 cm s ^-1）相比，壤土的水力传导率（3.74×10）在两个过程继续运行之后，^-3 cm s ^-1）增加了7.1倍。收集油层以进一步重复使用。经过三项处理后，RAMEB的出水量超过85％。收集的废水经合成吸收剂处理，然后合格排放，TOC值仅为2.6 mg L ^-1。通过将表面活性剂冲洗与微泡和其他设备结合使用，不仅可以有效节省反应时间，而且有机污染物可以在土壤中浓缩和再利用，因此无需其他处理。