The objective of this study was to investigate the effect of a removable physical barrier on the air sparging performance using a lab-scale aquifer model was investigated. The barrier was installed in water-saturated porous media, prior to the air sparging, by injecting calcium chloride aqueous solution into the aquifer with pre-applied alginate solution. Changes in the air flow direction and air flux at the media surface during air sparging were evaluated. With a hydrogel barrier set at the center of the media, the airflow detoured the barrier resulting in a bimodal air flux distribution at the media surface. While employing two gel-formed barriers positioned away from the media's center, the airflow concentrated specifically on the gap between the barriers. The hydrogel was successfully removed using a sodium bicarbonate solution (1.0 mol/L). Using the hydrogel barrier, the performance of air sparging was significantly enhanced for removing contaminants [tetrachloroethene (PCE) and n-hexane mixture] due to increased air flux; 9.8% of PCE applied (7.8 g) was removed during 120 min air sprging for the gel barrier system whereas no PCE was removed for the control. Alginate gel did not show significant sorption capacity for PCE. It was stable in the contaminant up to 68 days with reasonable loss of its mass. Findings of this study present a promising option for air sparging process specifically targeting the contaminant source zone in the aquifer.

本研究的目的是使用实验室规模的含水层模型来研究可移动物理屏障对空气喷射性能的影响。在空气喷射之前，通过将氯化钙水溶液与预先施加的藻酸盐溶液一起注入含水层，将屏障安装在水饱和的多孔介质中。评估空气喷射期间介质表面的气流方向和空气通量的变化。当水凝胶屏障设置在介质中心时，气流绕过屏障，导致介质表面出现双峰气流分布。当采用远离介质中心的两个凝胶形成的屏障时，气流特别集中在屏障之间的间隙上。使用碳酸氢钠溶液（1.0 mol/L）成功去除水凝胶。使用水凝胶屏障，由于空气通量增加，空气喷射的性能显着增强，可去除污染物[四氯乙烯（PCE）和正己烷混合物]；对于凝胶屏障系统，在 120 分钟的空气喷射过程中，9.8% 的 PCE（7.8 克）被去除，而对于对照系统，没有去除 PCE。海藻酸盐凝胶对四氯乙烯没有表现出显着的吸附能力。它在污染物中可稳定保存长达 68 天，并有合理的质量损失。这项研究的结果为专门针对含水层污染物源区域的空气喷射工艺提供了一种有前景的选择。