The use of biosurfactants for enhancing subsurface remediation
- Univ. of Arizona, Tucson, AZ (United States). Soil and Water Science Dept.
The use of water to flush sorptive chemicals, such as low-solubility organics and heavy metals, from contaminated sub-surface materials is now recognized as a very ineffective remediation method. Approaches based on fixing'' the chemicals in place are being developed. However, these methods are constrained by questions of long-term stability and political acceptability issues. Hence, other approaches are being developed based on the use of a reagent to facilitate removal. In this presentation the authors discuss the use of microbially produced reagents (e.g., biosurfactants) for enhancing the desorption and removal of low-solubility organic compounds and of heavy metals from soils. A nonmicelle forming biosurfactant, cyclodextrin, was investigated for its potential to solubilize and enhance the transport of organic compounds. An anionic rhamnolipid biosurfactant produced by Pseudomonas aeruginosa ATCC 9027 was investigated for its ability to complex cadmium (Cd[sup ++]) and to enhance the removal of CD[sup ++] from soil. Batch solution studies showed a direct relationship between rhamnolipid concentration and amount of Cd[sup ++] complexed. Rhamnolipid-Cd[sup ++] completion reached equilibrium within one hour and was pH dependent. Isotherms for sorption of rhamnolipid by three soils show significant sorption of rhamnolipid by three soils show significant sorption of rhamnolipid. Initial results from column experiments show that, while transport of rhamnolipid is retarded in comparison to nonreactive tracers, the presence of rhamnolipid significantly enhanced the removal of Cd[sup ++] from the soil.
- OSTI ID:
- 7124775
- Report Number(s):
- CONF-9410209--
- Journal Information:
- Ground Water; (United States), Journal Name: Ground Water; (United States) Vol. 32:5; ISSN GRWAAP; ISSN 0017-467X
- Country of Publication:
- United States
- Language:
- English
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