Perfluoroalkyl and polyfluoroalkyl substances

September 20, 2022

The objective of this study was to evaluate a cross-section of full-scale on-site landfill treatment systems to measure changes in PFAS concentrations. Leachate samples were collected before and after treatment from 15 facilities and were evaluated for 26 PFAS, including 11 perfluoroalkyl carboxylic acids (PFCAs), 7 perfluoroalkyl sulfonic acids (PFSAs), and 8 perfluoroalkyl acid precursors (PFAA-precursors). The transformation of precursors was evaluated by the total oxidizable precursor (TOP) assay. Results showed no obvious reductions in total measured PFAS (∑26PFAS) for on-site treatment systems including ponds, aeration tanks, powdered activated carbon (PAC), and sand filtration. Among evaluated on-site treatment systems, only systems fitted with reverse osmosis (RO) showed significant reductions (98-99 %) of ∑26PFAS in the permeate. Results from the TOP assay showed that untargeted PFAA-precursors converted into targeted short-chain PFCAs increasing ∑26PFAS in oxidized samples by 30 %, on average.

Overall, the results of this study confirm the efficacy of RO systems and suggest the presence of additional precursors beyond those measured in this study. SCS is part of the technical advisory group for this collaboration of the schools in Florida and the EPA. SCS’s Liquid Management Practice is helping the group with on-site work at landfills.

The study is publishing here: Concentrations of perfluoroalkyl and polyfluoroalkyl substances before and after full-scale landfill leachate treatment.

Chen Y, Zhang H, Liu Y, Bowden JA, Tolaymat TM, Townsend TG, Solo-Gabriele HM.
Waste Manag. 2022 Sep 6;153:110-120. doi: 10.1016/j.wasman.2022.08.024. Online ahead of print.
PMID: 36084369

The following universities with EPA are affiliated with the study:

1. Department of Civil, Architectural, and Environmental Engineering, College of Engineering, University of Miami, Coral Gables, FL.
2. Department of Environmental Engineering Sciences, College of Engineering, University of Florida, Gainesville, FL.
3. Department of Environmental Engineering Sciences, College of Engineering, University of Florida, Gainesville, FL; Center for Environmental and Human Toxicology & Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL.
4. Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH.
5. Department of Civil, Architectural, and Environmental Engineering, College of Engineering, University of Miami, Coral Gables, FL.