The role of microbial reductive dechlorination of TCE at a phytoremediation site

International Journal of Phytoremediation
By: , and 

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Abstract

In April 1996, a phytoremediation field demonstration site at the Naval Air Station, Fort Worth, Texas, was developed to remediate shallow oxic ground water (<3.7 m deep) contaminated with chlorinated ethenes. Microbial populations were sampled in February and June 1998. The populations under the newly planted cottonwood trees had not yet matured to an anaerobic community that could dechlorinate trichloroethene (TCE) to cis-1,2-dichloroethene (DCE); however, the microbial population under a mature (∼22-year-old) cottonwood tree about 30 m southwest of the plantings had a mature anaerobic population capable of dechlorinating TCE to DCE, and DCE to vinyl chloride (VC). Oxygen-free sediment incubations with contaminated groundwater also demonstrated that resident microorganisms were capable of the dechlorination of TCE to DCE. This suggests that a sufficient amount of organic material is present for microbial dechlorination in aquifer microniches where dissolved O2 concentrations are low. Phenol, benzoic acid, acetic acid, and a cyclic hydrocarbon, compounds consistent with the degradation of root exudates and complex aromatic compounds, were identified by gas chromatography/mass spectrometry (GC/MS) in sediment samples under the mature cottonwood tree. Elsewhere at the site, transpiration and degradation by the cottonwood trees appears to be responsible for loss of chlorinated ethenes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The role of microbial reductive dechlorination of TCE at a phytoremediation site
Series title International Journal of Phytoremediation
DOI 10.1080/16226510390856484
Volume 5
Issue 1
Year Published 2003
Language English
Publisher Taylor and Francis
Contributing office(s) Toxic Substances Hydrology Program
Description 15 p.
First page 73
Last page 87
Country United States
State Texas
City Fort Worth
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