Challenges and Remediation Strategies for Per- and Polyfluoroalkyl Substances (PFAS) Contamination in Composting

Abstract

Municipal solid waste (MSW) is projected to rise to 3.4 billion tonnes by 2050, with only 33% undergoing environmentally friendly management practices. Achieving a circular economy involves sustainable approaches, among which diverting waste from landfills to composting plays a crucial role. However, many of the products society uses and discards in MSW daily contain per- and polyfluoroalkyl substances (PFAS), raising concerns that composts may inadvertently introduce PFAS into the environment, posing a significant challenge to waste management and environmental sustainability. PFAS have been detected in compost at concentrations ranging between 1.26–11.84 µg/kg. Composts are therefore a source of PFAS contamination, posing risks to human and ecosystem health. Impactful technologies are therefore required for PFAS remediation during the composting process. This review examines the composting process as a sustainable organic waste management technology, examining the various systems employed, compost quality, and uses, particularly emphasising the challenge posed by PFAS contamination. The review provides novel insights into possible PFAS remediation technologies. A comprehensive understanding of PFAS origin, fate, and transformation during the composting process is lacking, creating substantial knowledge gaps regarding the inputs processes contributing most to PFAS accumulation in the final product. Addressing these gaps in future studies is crucial for minimising PFAS discharge into the environment and developing an effective remediation approach. This review highlights the urgent need for innovative solutions to mitigate PFAS contamination in compost and the importance of advancing research and technology to achieve sustainable waste management objectives.