Field Performance of Air-Sparging System for Removing TCE from Groundwater

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• 作者：Alan J. Rabideau ; James M. Blayden ; and Chandragupta Ganguly
• 刊名：Environmental Science & Technology
• 出版年：1999
• 出版时间：January 1, 1999
• 年：1999
• 卷：33
• 期：1
• 页码：157 - 162
• 全文大小：119K
• 年卷期：v.33,no.1(January 1, 1999)
• ISSN：1520-5851

文摘

The removal of volatile organic compounds from groundwaterby air sparging (AS) is well-established, although reliablemethods for predicting the time required to reach site closurehave not been established. To develop an improvedunderstanding of mass transfer processes that limit ASperformance, two extended controlled shutdowns of anoperating AS system were performed. Monitoring of TCEconcentrations in source zone groundwater indicated"tailing" and "rebound" behavior similar to that observedfor pump-and-treat systems. A simple two-compartmentmodel provided a reasonable description of the 3-year AShistory, using parameters calibrated from data collectedduring the first shutdown period. Comparison of the calibratedrate constants with parameters estimated from laboratorysoil columns suggests that, for the study site, aqueousdiffusion to discrete air channels has a stronger influenceon system performance than rate-limited desorption.Predictions based on the calibrated model indicated thatrestoration of the source zone to drinking water standardswould require approximately 1 decade for the currentAS system.