title: Effects of Aqueous Film-Forming Foams (AFFFs) on Trichloroethene (TCE) Dechlorination by a Dehalococcoides mccartyi-Containing Microbial Community.
abstract: The application of aqueous film-forming foams (AFFFs) to extinguish chlorinated solvent-fueled fires has led to the co-contamination of poly- and perfluoroalkyl substances (PFASs) and trichloroethene (TCE) in groundwater and soil. Although reductive dechlorination of TCE by Dehalococcoides mccartyi is a frequently used remediation strategy, the effects of AFFF and PFASs on TCE dechlorination are not well-understood. Various AFFF formulations, PFASs, and ethylene glycols were amended to the growth medium of a D. mccartyi-containing enrichment culture to determine the impact on dechlorination, fermentation, and methanogenesis. The community was capable of fermenting organics (e.g., diethylene glycol butyl ether) in all AFFF formulations to hydrogen and acetate, but the product concentrations varied significantly according to formulation. TCE was dechlorinated in the presence of an AFFF formulation manufactured by 3M but was not dechlorinated in the presence of formulations from two other manufacturers. Experiments amended with AFFF-derived PFASs and perfluoroalkyl acids (PFAAs) indicated that dechlorination could be inhibited by PFASs but that the inhibition depends on surfactant concentration and structure. This study revealed that the fermentable components of AFFF can stimulate TCE dechlorination, while some of the fluorinated compounds in certain AFFF formulations can inhibit dechlorination.
authors.affiliation: Department of Civil and Environmental Engineering, University of California , Berkeley, California, 94720 United States.
authors.forename: Katie C
authors.initials: KC
authors.lastname: Harding-Marjanovic
authors.affiliation: Department of Civil and Environmental Engineering, University of California , Berkeley, California, 94720 United States.
authors.forename: Shan
authors.initials: S
authors.lastname: Yi
authors.affiliation: Department of Civil and Environmental Engineering, Colorado School of Mines , Golden, Colorado, 80401 United States.
authors.forename: Tess S
authors.initials: TS
authors.lastname: Weathers
authors.affiliation: Department of Civil and Environmental Engineering, Colorado School of Mines , Golden, Colorado, 80401 United States.
authors.forename: Jonathan O
authors.initials: JO
authors.lastname: Sharp
authors.affiliation: Department of Civil and Environmental Engineering, University of California , Berkeley, California, 94720 United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Sedlak
authors.affiliation: Department of Civil and Environmental Engineering, University of California , Berkeley, California, 94720 United States.|Earth Sciences Division, Lawrence Berkeley National Laboratory 1 Cyclotron Road, Berkeley, California, 94720 United States.
authors.forename: Lisa
authors.initials: L
authors.lastname: Alvarez-Cohen
mesh_terms: D041862:Chloroflexi / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005285:Fermentation; D005466:Fluorocarbons / Q000737:chemistry; D054879:Halogenation; D006859:Hydrogen / Q000378:metabolism; D059013:Microbial Consortia / Q000502:physiology*; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism; D014241:Trichloroethylene / Q000737:chemistry / Q000378:metabolism*; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism
chemical_list: D005466:Fluorocarbons; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D014867:Water; D014241:Trichloroethylene; D006859:Hydrogen