Investigating the partitioning behavior of per- and polyfluoroalkyl substances (PFAS) during thermal landfill leachate evaporation

• Published in: Journal of hazardous materials Vol. 472; p. 134500
• Main Authors: Cerlanek, Allison R., Timshina, Alina S., Robey, Nicole, Lin, Ashley M., Solo-Gabriele, Helena M., Townsend, Timothy G., Bowden, John A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.07.2024
• Subjects: carboxylic acids; evaporation; Landfill leachate; landfill leachates; landfills; liquid chromatography; Partitioning; Per- and polyfluoroalkyl substances; PFAS; sludge; tandem mass spectrometry; wastewater treatment; water vapor; Per- and polyfluoroalkyl substances; Partitioning; Landfill leachate; PFAS
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.134500

Thermal landfill leachate evaporator systems can reduce the volume of leachate by up to 97%, while releasing water vapor and producing residuals (volume-reduced leachate and sludge) that are managed on-site. On-site thermal evaporators offer landfill operators leachate management autonomy without being subject to increasingly stringent wastewater treatment plant requirements. However, little is known about the partitioning of PFAS within these systems, nor the extent to which PFAS may be emitted into the environment via vapor. In this study, feed leachate, residual evaporated leachate, sludge, and condensed vapor were sampled at two active full-scale thermal landfill leachate evaporators and from a laboratory-scale leachate evaporation experiment. Samples were analyzed for 91 PFAS via ultra-high pressure liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS). Similar trends were observed from Evaporator 1, Evaporator 2, and the laboratory-scale evaporator; ∑PFAS were concentrated in the residual evaporated leachate during evaporation by a factor of 5.3 to 20. All condensed vapors sampled (n = 5) contained PFAS, predominantly 5:3 fluorotelomer carboxylic acid (5:3FTCA), (full-scale vapors 729 – 4087 ng/L PFAS; lab-scale vapor 61.0 ng/L PFAS). For Evaporators 1 and 2, an estimated 9 – 24% and 10%, respectively, of the PFAS mass entering the evaporators in leachate was released with vapor during the days of sample collection. ‘ [Display omitted] •Two full-scale thermal landfill leachate evaporation systems were evaluated.•Feed leachate, residual evaporated leachate, sludge, and condensed vapor sampled.•PFAS concentrate in evaporation residuals but were also measured in vapor.•5:3 FTCA was dominant PFAS in every condensed vapor sample.•Vapor released to environment estimated to emit 9–24 % of feed leachate PFAS mass.