Posted by Per- and polyfluorinated alkyl substances (PFASs), especially long-chain compounds such as perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), are widespread contaminants in global surface and groundwater. These substances pose significant health risks. Among the remediation methods available, adsorption is a highly effective and widely used technique for removing PFASs from water. The limited adsorption kinetics of traditional adsorbents have driven the development of advanced materials. In this study, we synthesized a β-cyclodextrin (β-CD) polymer crosslinked with decafluorobiphenyl (β-CD–DFB) for efficient extraction of both long- and short-chain PFASs at environmentally relevant concentrations. The β-CD–DFB polymer showed a substantial Langmuir adsorption capacity of 43.10 ± 4.30 mg/g and a tenfold greater affinity for long-chain PFOS compared to short-chain PFASs, with kinetics similar to powdered activated carbons (ACs) and biochars (Act-BCs). Remarkably, the β-CD–DFB polymer could reduce long-chain PFAS concentrations in water from 1 to 44 ng/L through adsorption, significantly below the advisory level of 70 ng/L set by the US Environmental Protection Agency and Korea Ministry of Environment. The adsorbent was easily regenerated with a simple methanol wash and maintained high performance over five adsorption–desorption cycles. Additionally, the adsorbent’s performance was unaffected by natural organic matter, like humic acid, which commonly fouls ACs. Tests with real wastewater samples confirmed the potential of β-CD–DFB as a promising adsorbent for selective removal of long-chain PFASs in water and wastewater treatment applications.
Monu Verma, Youngmin Hong, Surendar Moogi, Krishna Pal Singh, Sanjay Kumar Arora, Vinod Kumar, Manisha Nanda, Anuj Kumar, Hyunook Kim (2025) β–Cyclodextrin polymerization for selective separation of long-chain per- and poly-fluorinated alkyl substances at environmentally relevant concentrations. Separation and Purification Technology 379, 134917. https://doi.org/10.1016/j.seppur.2025.134917