Oregon State University
My name is Raymmah Garcia, I am a graduate student in the chemistry department at Oregon State University. I work in the Jennifer Field lab and study hydrocarbon surfactants in Aqueous Film Forming Foams (AFFs) and look at their impact in AFFF-contaminated groundwater.
Homologous Series to Find Hydrocarbon Surfactants in AFFFs and in AFFF-impacted Groundwater
Hydrocarbon surfactants and (per- and perfluoroalkyl substances) PFASs are used together in proprietary mixtures of Aqueous Film Forming Foams (AFFFs), which are used to extinguish hydrocarbon-based fuel fires. Although hydrocarbon surfactants are more abundant (5-10% w/w), more is known about the identity of PFASs that comprise only 0.9-1.5% w/w in AFFFs. Hydrocarbon surfactants in AFFFs and AFFF-contaminated groundwater have not previously been investigated. However, in this study, 34 AFFFs and eight AFFF-contaminated groundwater samples were analyzed for hydrocarbon surfactants by liquid chromatography quadrupole time-of-flight mass spectrometry. A hydrocarbon surfactant suspect screening list and a modified homologous series detection computational tool, enviMass were used for the identification of hydrocarbon surfactants in AFFFs and AFFF-contaminated groundwater. Of the 34 AFFFs analyzed, 29% of AFFFs contain polyethylene glycols, 18% contain alcohol ethoxylates, 12% contain betaines, 9% AFFFs contained nonylphenol polyethylene glycol and 6% of AFFFs contain alkyl ethoxysulfates. Of the surfactants shown to be in AFFFs, alcohol ethoxylates, alkyl sulfates and nonylphenol ethoxylates are seen in AFFF contaminated groundwater. AFFF-contaminated groundwater discharges into surface waters where hydrocarbon surfactants, which are likely persistent under anaerobic aquifer conditions, can begin to biodegrade under aerobic conditions. Additional research is needed to determine if AFFF-contaminated systems are discharging estrogenic nonylphenols that have the potential to adversely affect aquatic organisms in receiving surface waters.