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Efficient municipal solid waste (MSW) management promotes resource conservation, climate-change mitigation, public health, and environmental protection. A key aspect of environmental protection within MSW management is ensuring that potential pollutants are not released into the environment. One group of environmental pollutants of global concern is per- and polyfluoroalkyl substances (PFAS). Also known as “forever chemicals”, these are used in a wide variety of consumer products and industrial processes, and are known for their persistence. The fate of PFAS in waste-management processes, such as Waste-to-Energy (WtE), is largely unknown. This thesis aimed to investigate the fate of PFAS in a WtE plant.

Comprehensive sampling was performed to provide a synoptic overview of the occurrence and distribution of PFAS in residual streams, and to investigate the potential emission of PFAS from the WtE process to the environment.

Short-chain (C ≤ 7) perfluorocarboxylic acids were the dominant class of PFAS across all matrices analysed. PFAS was found in leachate from the temporary MSW stockpile located at the WtE plant, as well as in most incineration residues (e.g., bottom ash, condensate, and flue gas) during the incineration of MSW. Co-incineration of sewage sludge from a wastewater treatment plant and MSW (with the former added at 5–8 wt.% of the latter) led to an increase in the concentration of PFAS in all matrices, with the exception of filter ash and stack flue gas.

In general, the wet flue-gas treatment was able to capture some PFAS and transfer them to the in-house process-water treatment; however, further optimisation is required to increase the ability of this treatment to capture the shortest PFAS investigated (perfluorobutanoic acid).

Overall, these findings highlight that some PFAS are not fully degraded during WtE conversion, and that PFAS could enter the environment via both leaching from unburnt MSW and incineration residues.