PFAS in Incinerator Bottom Ash (IBA)

PFAS have been used since the 1950s in applications including fire-fighting foams, food packaging, textiles, and pesticides. Due to their persistence, bioaccumulation and toxicity, they are considered a concern for the environment and human health. Type D landfill sites are used to dispose of IBA from municipal WTE plants. Landfill operators require further research into PFAS contamination in slag, ongoing PFAS input, PFAS mobilisation into leachate and resulting leachate treatment requirements.

While the analytical methods currently in use tend to yield relatively low PFAS levels in deposited IBA, PFAS concentrations approaching regulatory limits are sometimes detected in landfill leachate. The research commission awarded to UMTEC aims to understand the causes of this discrepancy, identify the relevant release mechanisms, and derive appropriate measures.

UMTEC is sampling, fractionating and analysing IBA from various waste-to-energy plants, and characterising their PFAS concentrations and profiles. Laboratory experiments are also being conducted to investigate trigger factors relevant to PFAS mobilisation and release under landfill conditions. Recommendations for robust laboratory analysis, as well as for the operation and monitoring of IBA landfills, will be derived from the results.