Evaluation of Soil Solid Amendments for TCE Biodegradation in a Biobarrier System
Yelena
Katsenovich, Zuhal Öztürk, Marshall Allen, and Gary R. Wein
Abstract
Permeable biobarrier systems (PBSs) are being recognized as low-cost passive
bioremediation technologies for chlorinated organic contamination. This
innovative technology can play a crucial and effective role in site restorations.
Laboratory-scale experiments were conducted to investigate the biodegradation
of trichloroethylene (TCE) to ethylene in shallow groundwater through
the use of a PBS enhanced by bioaugmentation at the U.S. Department of
Energy's Savannah River Site (SRS). Two composts and two plant amendments,
eucalyptus mulch (EM) and corncobs (CC), were examined for their effectiveness
at creating and maintaining conditions suitable for TCE anaerobic dechlorination.
These materials were evaluated for their (1) nutrient and organic carbon
content, (2) TCE sorption characteristics, and (3) longevity of release
of nutrients and soluble carbon in groundwater to support TCE dechlorination.
Native bacteria in the columns had the ability to convert TCE to dichloroethenes
(DCEs); however, the inoculation with the TCE-degrading culture greatly
increased the rate of biodegradation. This caused a significant increase
in by-product concentration, mostly in the form of DCEs and vinyl chloride
(VC) followed by a slow degradation to ethylene. Of the tested amendments,
eucalyptus mulch was the most effective at supporting the reductive dechlorination
of TCE. Corncobs created a very acidic condition in the column that inhibited
dechlorination.
SREL Reprint #3042
Katsenovich, Y., Z. Öztürk, M. Allen, and G. R. Wein 2007. Evaluation
of Soil Solid Amendments for TCE Biodegradation in a Biobarrier System.
Remediation Summer 2007:67-80.
