Investigation of perfluoroalkyl carboxylic and sulfonic acids in leachates from industrial and municipal solid waste landfills, and their treated waters and effluents from their closest leachate treatment plants.

Per- and polyfluoroalkyl substances (PFASs) are used in products, such as aqueous film-forming foam and fluorochemical surfactants, because of their high chemical stability. Although the use of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in PFASs has decreased because of replacement, many products containing them are landfilled. Determining accurate PFCA and PFSA concentrations of leachate from waste disposal sites is necessary, although reports on landfills are scarce, especially industrial waste landfills (IWLs). Little information about the fate of PFCAs and PFSAs during leachate treatment processes is available. Herein, the congener contributions of PFCAs and PFSAs in leachates of IWLs and municipal solid waste landfills (MSWLs) and changes in their concentrations before and after leachate treatment are reported. PFCA and PFSA concentrations in landfill leachates ranged from < 3.0 to 27,000 ng/L (n = 40), and concentrations in the leachates from IWLs were higher than those from MSWLs. Short-chain (C4–C9) PFCAs and PFSAs were well-detected, whereas long-chain (> C9) ones were rarely detected. Moreover, > 95% of these substances were removed in the activated carbon and reverse osmosis (RO) membrane treatments. These results suggest that activated carbon and RO membrane treatments effectively remove PFCAs and PFSAs from leachates. [ABSTRACT FROM AUTHOR]