Per- and polyfluoroalkyl alkyl substances (PFASs), diethyl glycol monobutyl ether (DGBE) and, hydrocarbon surfactants are major components in aqueous film-forming foam (AFFF) that is used to effectively fight hydrocarbon-based fuel fires at military bases and airports. They are persistent, bioaccumulative, and toxic to the environment, wildlife, and humans which making their treatment and removal a priority. Aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylenes (BTEX) are often found as co-contaminants from such fire and firefighter training events. BTEX is often remediated by stimulating indigenous BTEX microbial degraders which use BTEX as a carbon and energy source, and electron donor. Therefore, understanding the impact of AFFF on BTEX biodegradation could inform bioremediation efficiency. We found that an AFFF-impacted soil community exposed to 30 μM of PFASs from the 3M California Guardian AFFF completely inhibited the aerobic biodegradation of BTEX for an experiment for 35 days. Experiments with the labile organic DGBE—which comprises up to 20% of AFFF formulations—showed that BTEX biodegradation was halted due to PFASs’ inhibition, rather than microbial selectivity for the DGBE over BTEX. Perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonamide amine (PFHxSAm) are the main PFASs found in 3M AFFF, potentially driving inhibition to the microbial activity. Our findings can inform potential roadblocks in BTEX bioremediation sites where both BTEX and AFFF are present.

Microbial inhibition of aerobic BTEX biodegradation caused by the influence of fluorinated compounds in aqueous film-forming foams (AFFFs)

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.