Comparative analysis of enhanced adsorption and thermal decomposition of oil-borne PFAS using CeO2 nanoparticles and activated carbon

Abstract

Per- and poly-fluoroalkyl substances (PFAS) are widely used as surfactants in the oil and gas industry, presenting significant environmental and health risks due to their persistence and mobility. While prevailing research primarily targets PFAS removal from aqueous environments, this study explores the efficacy of nanosized cerium oxide nanoparticles (CeO₂ NPs) and traditional activated carbon (AC) in removing PFAS from organic media via adsorption and thermal degradation. Both adsorbents exhibited robust adsorption capabilities; however, their interaction mechanism with PFAS differ significantly. CeO₂ NPs primarily engage in chemical adsorption with PFAS, whereas AC relies on hydrophobic interactions. Additionally, CeO₂ NPs outperformed AC in thermal degradation experiments, achieving approximately 95 % decomposition of PFOS at 400 °C, compared to only 52 % with AC. Furthermore, the formation of stable Ce−F bonds at high temperatures significantly reduced fluoride ion release from CeO₂ NPs, underscoring their potential to minimize environmental impact. This study is the first to apply both AC and CeO₂ NPs for PFAS removal from organic media and to elucidate their distinct adsorption and thermal decomposition mechanisms, highlighting the superior performance of CeO₂ NPs in environmental remediation of PFAS.