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Wastewater treatment plants generate a solid waste known as biosolids. The most common management option for biosolids is to beneficially reuse them as an agricultural amendment, but because of the risk of pathogen exposure, many regulatory bodies require pathogen reduction before biosolids reuse. Per- and polyfluoroalkyl substances (PFAS) are well documented in biosolids, but limited information is available on how biosolids treatment processes impact PFAS. Furthermore, quantification of PFAS has focused on perfluoroalkyl acids (PFAAs) which are a small fraction of thousands of PFAS known to exist. The objective of this study was to quantify 92 PFAS in biosolids collected from eight biosolids treatment facilities before and after four pathogen treatment applications: composting, heat treatment, lime treatment, and anaerobic digestion. Overall, total PFAS concentrations before and after treatment were dominated by PFAA precursor species, in particular, diPAPs which accounted for a majority of the mass of the Σ 92 PFAS. This differs from historic data that found PFAAs, primarily PFOS, to dominate total PFAS concentrations. Treatment options such as heat treatment and composting changed the ratio of PFAA precursors to PFAAs indicating a transformation of PFAS during treatment. This study finds that PFAA precursors are likely underrepresented by other studies and make up a larger percentage of the total PFAS concentration in biosolids than previously estimated.

One hundred and seventeen street sweeping samples were collected and analyzed for per- and polyfluoroalkyl substances (PFAS). Fifty-six samples were collected in one city (Gainesville, Florida) allowing for an in-depth city-wide characterization. Street sweepings from five other urban areas, (Orlando, n = 15; Key West, n = 15; Pensacola, n = 12; Tampa, n = 13; and Daytona Beach, n = 6) were analyzed to provide a city-to-city comparison of PFAS. Within our analytical workflow, 37 PFAS were quantified across all samples, while the maximum number of PFAS quantified at one site was 26. Of those PFAS quantified in Gainesville, 60% were perfluoroalkyl acids (PFAAs) and 33% were precursors to PFAA. Among the PFAAs, short-chain perfluoroalkyl carboxylic acids (PFCAs) were the dominant class representing 26% of the total PFAS by concentration. In the comparison across different urban cities, the dominant compound by concentration and frequency of detection varied; however, perfluorooctanoic acid (PFOA) and linear perfluorooctanesulfonic acid (PFOS lin ) were the two PFAS that were detected the most frequently. This study documents the first-time detection of hexadecafluorosebacic acid and perfluoro-3,6,9-trioxaundecane-1,11-dioic acid within environmental samples.

Municipal solid waste contain diverse and significant amounts of per- and polyfluoroalkyl substances (PFAS), and these compounds may transform throughout the "landfilling" process from transport through landfill degradation. Fresh vehicle leachates, from commercial and residential waste collection vehicles at a transfer station, were measured for 51 PFAS. Results were compared to PFAS levels obtained from aged landfill leachate at the disposal facility. The landfill leachate was dominated by perfluoroalkyl acids (PFAAs, including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs); 86% of the total PFAS, by median mass concentration), while the majority of PFAS present in commercial and residential waste vehicle leachate were PFAA-precursors (70% and 56% of the total PFAS, by median mass concentration, respectively), suggesting precursor transformation to PFAAs during the course of landfill disposal. In addition, several PFAS, which are not routinely monitored-perfluoropropane sulfonic acid (PFPrS), 8-chloro-perfluoro-1-octane sulfonic acid (8Cl-PFOS), chlorinated polyfluoroether sulfonic acids (6:2, 8:2 Cl-PFESAs), sodium dodecafluoro-3H-4,8-dioxanonanoate (NaDONA), and perfluoro-4-ethylcyclohexanesulfonate (PFECHS)-were detected. Potential degradation pathways were proposed based on published studies: transformation of polyfluoroalkyl phosphate diester (diPAPs) and fluorotelomer sulfonic acids (FTS) to form PFCAs via formation of intermediate products such as fluorotelomer carboxylic acids (FTCAs)., Competing Interests: The authors declare no competing financial interest.

Large volumes of per- and polyfluoroalkyl substances (PFAS)-contaminated wastewaters, such as municipal solid waste landfill leachates, pose a challenge for PFAS treatment technologies in practice today. In this study, the surfactant properties of PFAS were exploited to concentrate the compounds in foam produced via the bubble aeration of landfill leachate. The effectiveness of the foaming technique for concentrating PFAS varied by compound, with a mean removal percentage (the percent difference between PFAS in leachate before and after foam removal) of 69% and a median removal percentage of 92% among the 10 replicate foaming experiments. This technique appears to be similarly effective at sequestering sulfonates and carboxylate PFAS compounds and is less effective at concentrating the smallest and largest PFAS molecules. The results of this study suggest that for the pretreatment or preconcentration of landfill leachates, foaming to sequester PFAS may provide a practical approach that could be strategically coupled to high-energy PFAS-destructive treatment technologies. The process described herein is simple and could feasibly be applied at a relatively low cost at most landfills, where leachate aeration is already commonplace.

Thousands of per- and polyfluoroalkyl substances (PFAS) exist in the environment and pose a potential health hazard. Suspect and nontarget screening with liquid chromatography (LC)-high-resolution tandem mass spectrometry (HRMS/MS) can be used for comprehensive characterization of PFAS. To date, no automated open source PFAS data analysis software exists to mine these extensive data sets. We introduce FluoroMatch, which automates file conversion, chromatographic peak picking, blank feature filtering, PFAS annotation based on precursor and fragment masses, and annotation ranking. The software library currently contains ∼7 000 PFAS fragmentation patterns based on rules derived from standards and literature, and the software automates a process for users to add additional compounds. The use of intelligent data-acquisition methods (iterative exclusion) nearly doubled the number of annotations. The software application is demonstrated by characterizing PFAS in landfill leachate as well as in leachate foam generated to concentrate the compounds for remediation purposes. FluoroMatch had wide coverage, returning 27 PFAS annotations for landfill leachate samples, explaining 71% of the all-ion fragmentation (CF 2 ) n related fragments. By improving the throughput and coverage of PFAS annotation, FluoroMatch will accelerate the discovery of PFAS posing significant human risk.