Authors: Babur S Mirza Darwin L Sorensen R Ryan Dupont Joan E McLean
Publish Date: 2015/11/05
Volume: 100, Issue: 5, Pages: 2367-2379
Abstract
Trichloroethene TCE in groundwater is a major health concern and biostimulation/bioaugmentationbased strategies have been evaluated to achieve complete reductive dechlorination with varying success Different carbon sources were hypothesized to stimulate different extents of TCE reductive dechlorination Ecological conditions that developed different dechlorination stages were investigated by quantitating Dehalococcoides 16S rRNA Dhc and reductive dehalogenase gene abundance and by describing biogeochemical properties of laboratory columns in response to this biostimulation Eight large columns 183 cm × 152 cm packed with aquifer material from Hill AFB Utah that were continuously fed TCE for 75 years Duplicate columns were biostimulated with whey or one of two different Newman Zone® emulsified oil formulations containing either nonionic surfactant EOLN or standard surfactant EOL Two columns were nonstimulated controls Complete whey amended partial EOLN amended limited EOL and nonTCE dehalogenating systems controls developed over the course of the study Bioaugmentation of half of the columns with Bachman Road culture 3 years prior to dismantling did not influence the extent of TCE dehalogenation Multivariate analysis clustered samples by biostimulation treatments and extent of TCE dehalogenation Dhc tceA and bvcA gene concentrations did not show a consistent relationship with TCE dehalogenation but the vcrA gene was more abundant in completely dehalogenating wheytreated columns The whey columns developed strongly reducing conditions producing FeII sulfide and methane Biostimulation with different carbon and energy sources can support high concentrations of diverse Dhc but carbon addition has a major influence on biogeochemical processes effecting the extent of TCE dehalogenation
Keywords: