Concentrations of perfluoroalkyl and polyfluoroalkyl substances before and after full-scale landfill leachate treatment
Citation:
Chen, Y., H. Zhang, Y. Liu, J. Bowden, T. Tolaymat, T. Townsend, AND H. Solo-Gabriele. Concentrations of perfluoroalkyl and polyfluoroalkyl substances before and after full-scale landfill leachate treatment. WASTE MANAGEMENT. Elsevier Science Ltd, New York, NY, 153:110-120, (2022). https://doi.org/10.1016/j.wasman.2022.08.024
Impact/Purpose:
Many consumer and industrial products containing per- and polyfluoroalkyl substances (PFAS) are disposed of in landfills at the end of their usage, with PFAS in these products transferred into landfill leachates. On-site leachate treatment is one possible method to remove PFAS in leachates. Many landfills are equipped with on-site leachate treatment systems, but few full-scale facilities have been systematically evaluated for PFAS removal. The objective of this study was to evaluate a cross-section of full-scale on-site landfill treatment systems to measure their efficacy for PFAS removal.
Description:
Many consumer and industrial products containing per- and polyfluoroalkyl substances (PFAS) are disposed of in landfills at the end of their usage, with PFAS in these products transferred into landfill leachates. On-site leachate treatment is one possible method to remove PFAS in leachates. Many landfills are equipped with on-site leachate treatment systems, but few full-scale facilities have been systematically evaluated for PFAS removal. The objective of this study was to evaluate a cross-section of full-scale on-site landfill treatment systems to measure their efficacy for PFAS removal. 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 sulfonates (PFSAs) and 8 perfluoroalkyl acid precursors (PFAA-precursors). Transformation of precursors was evaluated by the total oxidizable precursor (TOP) assay. Results showed no obvious reductions in total measured PFAS concentrations for on-site treatment systems that included ponds, aeration tanks, powered activated carbon (PAC), and sand filtration. However, aeration processes showed evidence of PFAS accumulation towards the surface layers and this accumulation can be possibly exploited during subsequent treatment. Among evaluated on-site treatment systems only systems fitted with reverse osmosis (RO) showed significant reductions of total measured PFAS in the permeate (98% − 99% removal). Results from the TOP assay showed that untargeted PFAA-precursors converted into targeted short-chain perfluoroalkyl carboxylic acids (PFCAs) increasing total PFAS in oxidized samples by 30%, on average. Overall, results of this study confirm the efficacy of RO systems and suggest the presence of additional precursors beyond those measured in the current study.
URLs/Downloads:
DOI: Concentrations of perfluoroalkyl and polyfluoroalkyl substances before and after full-scale landfill leachate treatment
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