Air flow optimization and surfactant enhancement to remediate toluene‐contaminated saturated soils using air sparging

Abstract

This paper presents the results of laboratory experiments that investigate the removal of volatile organic compounds from saturated soils through the use of air sparging. Three series of experiments were performed in a column test apparatus using two different soils to represent actual field conditions, namely, a fine gravel and a medium‐to‐fine Ottawa sand (both obtained from sources near Chicago, Illinois, USA) contaminated with toluene, a major constituent of petroleum products. The results showed that toluene was removed from gravel very efficiently using air sparging; complete removal was achieved using a variety of air flow rates. However the toluene removal rates in tests using sand were significantly less. Even at the highest air flow rate used during testing, complete toluene removal took eight times longer than in comparable tests using gravel. With low air flow rates this was not achieved even after 17 hours of testing. It was further found that the injection of foams generated with surfactants, SDS and witconol SN70, at low air flow rates during the use of air sparging was found to accelerate the bulk removal of toluene in sand, but the use of surfactants did not facilitate the removal of residual levels of contamination.

Citation

Reddy, K.R., Semer, R. and Adams, J.A. (1999), "Air flow optimization and surfactant enhancement to remediate toluene‐contaminated saturated soils using air sparging", Environmental Management and Health, Vol. 10 No. 1, pp. 52-63. https://doi.org/10.1108/09566169910257239