Mechanisms of Surfactant-Enhanced Air Sparging
QIN Chuan-yu,ZHAO Yong-sheng and ZHENG Wei
DOI:10.11835/j.issn.1674-4764.2012.02.023
Received ,Revised , Accepted , Available online July 01, 2015
Volume ,2012,Pages 138-142
- Abstract
The changing mechanisms of air saturation in groundwater in different air travelling modes during surfactant-enhanced air sparging were investigated using a series of one-dimensional column experiments with the media of medium sand (025～050 mm) and gravel (5～10 mm) respectively. The results demonstrate that when air travels in the form of discrete channels, air saturation increases gradually with surface tension decreasing. When the surface tension is 495 mN/m, air saturation would not increase but slightly decreases instead. The decrease of capillary pressure caused by surface tension reduction is the main cause of increase of air saturation. When air travels in the form of bubbles, the air saturation improves gradually as the surfactant concentration decreases when the SDBS concentration is lower than 1 000 mg/L, and air saturation in porous media is directly affected by foam stability.