The magnetic removal of PFAS from water − from molecules to microplastics

Abstract

Per- and polyfluoroalkyl substances (PFAS), known as “ forever chemicals ”, pose a persistent environmental threat due to their chemical stability, bioaccumulation and widespread presence in water sources. Traditional treatment methods are often limited to remove PFAS, especially at low concentrations or in complex mixtures. This study presents functionalized superparamagnetic iron oxide nanoparticles (SPIONs) to capture various PFAS, including amphiphilic and neutral compounds or even microplastics, from water. By tuning the SPION surface chemistry with a self-assembled monolayer (SAM) for electrostatic and hydrophobic interactions, we achieved high removal efficiencies in diverse conditions, including a contaminated drinking water source, soil wash-off, river water and laundry wastewater. Regenerable hydrophobic SPIONs maintained high performance, reducing PFAS levels up to 95.4%. These findings support SPIONs as a scalable, effective solution for broad-range PFAS removal even in complex environments. Their applicability across different matrices underscores their global relevance to mitigate PFAS pollution in industrial effluents, wastewater streams, and natural ecosystems.