ABSTRACT

The effect of lowered groundwater surface tension using alcohols and surfactants, and increased viscosity using a thickener on the performance of the air sparging (AS) process was investigated, and the mechanism of facilitated air intrusion into the saturated zone during surfactant-enhanced air sparging (SEAS) was proposed.When aqueous solutions of alcohols (e.g., ethyl alcohol) displaced the resident water in a sand-packed column, the air saturation slightly decreased during AS, whereas the addition of surfactants increased air saturation. During the AS process, a significant difference in the air pressure measurements was observed, depending on the chemicals (alcohols and surfactants). Significantly higher air pressure was measured during SEAS than AS process with alcohol solutions. In this study, it is proposed that the foam formation and displacement through the soil interstices during the SEAS process increases air pressure. And this additional air pressure is responsible for the additional air intrusion into the smaller pores at lowered surface tension. Increased hydraulic pressure or water viscosity showed no significant effect on the air saturation during alcohol-applied AS. However, during SEAS, the increased viscosity using a thickener increased the viscosity of the foam inducing high air pressure, resulting in further enhanced air saturation.

摘要

研究了使用醇和表面活性剂降低地下水表面张力和使用增稠剂增加粘度对空气喷射 (AS) 工艺性能的影响，以及在表面活性剂增强空气喷射过程中促进空气侵入饱和区的机制。 SEAS) 被提出。当酒精（例如，乙醇）的水溶液置换沙填充柱中的驻留水时，在 AS 期间空气饱和度略有下降，而表面活性剂的添加增加了空气饱和度。在 AS 过程中，观察到气压测量值存在显着差异，具体取决于化学品（酒精和表面活性剂）。在 SEAS 过程中测得的气压明显高于使用酒精溶液的 AS 过程。在这项研究中，建议在 SEAS 过程中通过土壤间隙的泡沫形成和置换增加了气压。而这种额外的气压是造成在较低表面张力下额外的空气侵入较小孔隙的原因。在酒精应用 AS 期间，增加的液压或水粘度对空气饱和度没有显着影响。然而，在 SEAS 期间，使用增稠剂增加的粘度会增加泡沫的粘度，从而导致高气压，从而进一步提高空气饱和度。在酒精应用 AS 期间，增加的液压或水粘度对空气饱和度没有显着影响。然而，在 SEAS 期间，使用增稠剂增加的粘度会增加泡沫的粘度，从而导致高气压，从而进一步提高空气饱和度。在酒精应用 AS 期间，增加的液压或水粘度对空气饱和度没有显着影响。然而，在 SEAS 期间，使用增稠剂增加的粘度会增加泡沫的粘度，从而导致高气压，从而进一步提高空气饱和度。