Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloroethylene Co-Metabolism

Colwell, Rick ; Radtke, Corey ; Delwiche, Mark ; Newby, Deborah ; Petzke, Lynn ; Conrad, Mark ; Brodie, Eoin ; Lee, Hope ; Starr, Bob ; Dettmers, Dana ; Crawford, Ron ; Paszczynski, Andrzej ; Bernardini, Nick ; Paidisetti, Ravi ; Green, Tonia

Idaho National Engineering and Environmental Laboratory

关键词: Attenuation;    Genes;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Viability;    Simulation;   

DOI  :  10.2172/896426
RP-ID  :  ERSD-1027628-2006
RP-ID  :  None
RP-ID  :  896426

美国|英语

来源: UNT Digital Library

【 摘 要 】

Chlorinated solvent wastes (e.g., trichloroethene or TCE) often occur as diffuse subsurface plumes in complex geological environments where coupled processes must be understood in order to implement remediation strategies. Monitored natural attenuation (MNA) warrants study as a remediation technology because it minimizes worker and environment exposure to the wastes and because it costs less than other technologies. However, to be accepted MNA requires different ?lines of evidence? indicating that the wastes are effectively destroyed. We are studying the coupled biogeochemical processes that dictate the rate of TCE co-metabolism first in the medial zone (TCE concentration: 1,000 to 20,000 ?g/L) of a plume at the Idaho National Laboratory?s Test Area North (TAN) site and then at Paducah or the Savannah River Site. We will use flow-through in situ reactors (FTISR) to investigate the rate of methanotrophic co-metabolism of TCE and the coupling of the responsible biological processes with the dissolved methane flux and groundwater flow velocity. TCE co-metabolic rates at TAN are being assessed and interpreted in the context of enzyme activity, gene expression, and cellular inactivation related to intermediates of TCE co-metabolism. By determining the rate of TCE co-metabolism at different groundwater flow velocities, we will derive key modeling parameters for the computational simulations that describe the attenuation, and thereby refine such models while assessing the contribution of microbial co-metabolism relative to other natural attenuation processes. This research will strengthen our ability to forecast the viability of MNA at DOE and other sites contaminated with chlorinated hydrocarbons.