Microbial communities in anaerobic PFAS and VOC biodegradation soil microcosms

Per- and polyfluoroalkyl substances (PFAS) and volatile organic compounds (VOCs) are widespread contaminants that pose environmental health risks as they are known to bioaccumulate, have eco-toxicity effects, and are highly recalcitrant. Here, we conducted anaerobic, laboratory microcosm experiments to investigate the biotransformation of perfluorooctanesulfonic acid (PFOS) with a dechlorinating culture and chlorinated solvent co-contaminants. Microcosms were constructed with PFAS-contaminated soils from a U.S. Army installation (Fort Drum, New York) and simulated groundwater. All microcosms, except for a live sediment control, were amended with perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and 6:2 fluorotelomer sulfonate (6:2FtS). Replicate treatments were prepared with and without bioaugmentation with the WBC-2 dehalogenating culture and with and without addition of chlorinated volatile organic compounds (1,1,2,2-tetrachloroethane and trichloroethylene). Two additional treatments were prepared containing granular activated carbon. All microcosms were prepared in duplicate and sacrificed for sampling. Microbial communities were analyzed on sediment slurry collected at each sampling point using Illumina 16S iTag sequencing.