Surfactant foam/bioaugmentation technology for in situ treatment of TCE-DNAPLs.
Chlorinated solvents such as trichloroethylene (TCE) are prevalent aquifer contaminants. Depending on the degree of contamination, their physical properties may cause them to occur as dense nonaqueous-phase liquids (DNAPLs) making them difficult to remediate by pump-and-treat methods. Successful in situ bioremediation requires mobilization and dispersion of DNAPLs in order to reduce sediment concentrations to levels nontoxic to degradative bacteria. A bench-scale study was conducted to evaluate a novel remediation technology that utilized surfactant foam for mobilizing and dispersing TCE-DNAPLs combined with a bioaugmentation technology to remediate TCE in situ. Results using the anionic surfactant Steol CS-330 showed that foam injected into TCE-DNAPL-contaminated sand columns enhanced mobilization of TCE-DNAPLs. Mobilization was maximized when the foam was injected in a pulsed operation. Injection of foam followed by artificial groundwater (AGW) and then by foam again resulted in flushing 75% of the initial TCE-DNAPL through an 8-in. column (884 cm3 of sand). The residual TCE was dispersed within the column at concentration levels compatible with biodegradation (<500 {micro}g/g). Adding the TCE-degrading bacterial strain ENV 435 simultaneously with the second pulse of foam resulted in 95-99% degradation of the residual TCE. This level of remediation was achieved with a total of 3 pore volumes (foam/AGW/foam + bacteria) and an aqueous column retention time of 1 h.
- Research Organization:
- Argonne National Laboratory (ANL)
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 938390
- Report Number(s):
- ANL/ES/JA-30067
- Journal Information:
- Environ. Sci. Technol., Journal Name: Environ. Sci. Technol. Journal Issue: 11 ; Jun. 1, 1998 Vol. 32; ISSN ESTHAG; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- ENGLISH
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