Comparative Life Cycle Assessment of Pyrolysis vs. Incineration for Treating Sludge and Nanofiltration Concentrate from Landfill Leachate Treatment Plant Effluent Contaminated with PFAS

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants commonly found in landfill leachates and wastewater treatment plant (WWTP) effluents, posing significant risks to environmental and human health. This study evaluates the environmental impacts of two treatment methods - incineration and pyrolysis - for managing PFAS-rich waste, specifically the sludge generated in a Landfill Leachate Treatment Plant (LLTP) and the concentrate produced by a Nanofiltration (NF) system treating the effluent from the same plant. A Life Cycle Assessment (LCA) was performed to compare the environmental impacts of these methods in terms of Global Warming Potential (GWP), Marine Eutrophication (MEP) and Terrestrial Ecotoxicity (TETP). Pyrolysis treatment results in 26 % lower GWP impacts (70.8 kg CO2-eq per 1000 kg of input), 85 % lower MEP impacts (0.0065 kg N-eq per 1000 kg of input), and 91 % lower TETP impacts (216 kg 1,4-DBC-eq per 1000 kg of input) compared to incineration (96.2 kg CO2-eq, 0.0437 kg N-eq, and 2330 kg 1,4-DBC-eq per 1000 kg of input, respectively).The study highlights pyrolysis as a more eco-friendly and energy-efficient option for managing PFAS-rich waste, outperforming incineration in the considered environmental categories.