Influence of Viscous and Buoyancy Forces on the Mobilization of Residual Tetrachloroethylene during Surfactant Flushing
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- 作者：Kurt D. Pennell ; Gary A. Pope ; and Linda M. Abriola
- 刊名：Environmental Science & Technology
- 出版年：1996
- 出版时间：April 1996
- 年：1996
- 卷：30
- 期：4
- 页码：1328 - 1335
- 全文大小：687K
- 年卷期：v.30,no.4(April 1996)
- ISSN：1520-5851
文摘
The potential for nonaqueous phase liquid (NAPL)mobilization is one of the most important considerationsin the development and implementation of surfactant-based remediation technologies. Columnexperiments were performed to investigate the onsetand extent of tetrachloroethylene (PCE) mobilizationduring surfactant flushing. To induce mobilization,theinterfacial tension between residual PCE and theaqueous phase was reduced from 47.8 to 0.09 dyn/cm by flushing with different surfactant solutions.The resulting PCE desaturation curves are expressedin terms of a total trapping number (NT),whichrelates viscous and buoyancy forces to the capillaryforces acting to retain organic liquids within a porousmedium. The critical value of NT requiredto initiatePCE mobilization fell within the range of 2 ×10-5to 5 × 10-5, while complete displacement ofPCE wasobserved as NT approached 1 ×10-3. The interplayof viscous and buoyancy forces during PCEmobilization is illustrated in horizontal column experiments, in which angled banks of PCE were displacedthrough the columns. These results demonstrate thepotential contribution of buoyancy forces to PCEmobilization and provide a novel approach for predictingNAPL displacement during surfactantflushing.