Environ Technol. 2014 May-Jun;35(9-12):1190-8. doi: 10.1080/09593330.2013.865060.
This paper presents the results of a laboratory investigation of the influence zone (IZ) of air sparging (AS) in different media at different surface tension. Different kinds of media were used in two-dimensional tank experiments, designed to determine (1) the effect of surface tension reduction on the airflow pattern during AS in different air travelling modes (channels and bubbles) in homogeneous aquifer and (2) the airflow distribution and migration characteristics in heterogeneous aquifer at different surface tension during AS. The results demonstrated that in homogeneous gravel aquifer, the IZ was almost identical with or without surfactant addition into groundwater, the air saturation, however, was increased with decreasing surface tension. In homogeneous coarse sand tank saturated with 500 mg/L sodium dodecyl benzene sulphonate (SDBS) solution, the IZ was approximately 1.3 times larger than that in the same medium saturated with distilled water. In addition, the density of airflow channels was much larger in medium saturated with SDBS solution. In heterogeneous subsurface saturated with distilled water, when the permeability ratio between two adjoining layers was 8:1, air would bypass low-permeable soils. In contrast, the air would infiltrate into low-permeable soils when SDBS concentration in groundwater was 1000 mg/L. The results indicate that surfactant-enhanced air sparging can effectively improve the volatile organic compounds removal both in homogeneous and heterogeneous media.
本文介绍了在不同表面张力下，空气喷射（AS）在不同介质中的影响区（IZ）的实验室研究结果。在二维水箱实验中使用了不同类型的介质，旨在确定（1）在不同的空气流动模式（通道和气泡）下，表面张力降低对均质含水层中 AS 期间气流模式的影响，以及（2）在不同表面张力下 AS 期间非均质含水层中的气流分布和迁移特性。结果表明，在均质砾石含水层中，无论是否向地下水中添加表面活性剂，IZ 几乎相同，但随着表面张力的降低，空气饱和度增加。在饱和浓度为 500mg/L 的十二烷基苯磺酸钠（SDBS）溶液的均质粗砂水箱中，IZ 大约是在相同介质中饱和蒸馏水中的 1.3 倍。此外，在 SDBS 溶液饱和的介质中，气流通道的密度要大得多。在饱和蒸馏水的非均质地下水中，当两个相邻层之间的渗透率比为 8:1 时，空气会绕过低渗透性土壤。相比之下，当地下水中的 SDBS 浓度为 1000mg/L 时，空气会渗透到低渗透性土壤中。结果表明，表面活性剂增强的空气喷射可以有效地提高均质和非均质介质中挥发性有机化合物的去除率。
