Emission of\nPerfluoroalkyl Acids and Unidentified\nOrganofluorine from Swedish Municipal Waste Incineration Plants

Incineration is commonly used to dispose of waste contaminated\nwith per- and polyfluoroalkyl substances (PFAS), despite few experimental\ndata supporting the efficacy of this technique. To investigate the\nprevalence of PFAS in residuals from Swedish municipal waste incineration\n(MWI) plants, samples of fly ash, bottom ash, and flue gas condensate\nwere collected from 27 of Sweden’s 38 plants and analyzed for\n13 perfluoroalkyl acids (PFAAs). ∑<sub>13</sub>PFAA concentrations\nranged from 0.28 to 180 ng/L, 0.22–1.6 μg/kg, and 0.18–38\nμg/kg, in condensate, bottom ash, and fly ash, respectively\n(detection frequencies of 79, 21, and 30%, respectively). Total fluorine\n(TF) measurements in a subset of samples revealed concentrations of\n<0.20–11 mg F/L in condensate (n = 8) and 120–5400\nμg F/g in ashes (n = 8), the former of which was primarily attributed\nto inorganic fluorine. Extractable organofluorine (EOF) exceeded ∑<sub>13</sub>PFAA concentrations by up to 3 orders of magnitude (0.70–16\nμg F/g in fly ash [n = 3] and <0.80–9.0 μg F/L\nfor condensate [n = 2]), suggesting that the majority of fluorine\noccurring in MWI residuals remains unidentified. Collectively, these\ndata demonstrate that despite temperatures exceeding 1000 °C,\nPFAAs and other fluorinated substances may form and/or persist during\nincineration and risk being released to the environment via MWI residues.