Transport of per-/polyfluoroalkyl substances from leachate to groundwater as affected by dissolved organic matter in landfills.

The transport of per- and polyfluoroalkyl substances (PFAS) from landfill leachate to surrounding soil and groundwater poses a threat to human health via the food chain or drinking water. Studies have shown that the transport process of PFAS from the solid to liquid phase in the environment is significantly affected by dissolved organic matter (DOM) adsorption. However, the mechanism of PFAS release from landfill solids into leachate and its transport to the surrounding groundwater remains unclear. In this study, we identified the composition of PFAS and DOM components and analyzed the association between DOM components, physicochemical factors, and PFAS concentrations in landfill leachate and groundwater. This study demonstrated that the frequency of PFAS detection in the samples was 100%, and the PFAS concentrations in leachate were greater than in the groundwater samples. Physicochemical factors, such as ammonium-nitrogen (NH ₄ ⁺ -N), sodium (Na), calcium (Ca), DOM components C4 (macromolecular humic acid), SUVA ₂₅₄ (aromatic component content), and A _240-400 (humification degree and molecular weight), were strongly correlated with PFAS concentrations. In conclusion, PFAS environmental risk management should be enhanced in landfills, especially in closed landfills, or landfills that are scheduled to close in the near future.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Inc. All rights reserved.)