Posted by Chemical diversity and persistence of per- and polyfluoroalkyl substances (PFAS), particularly short-chain variants, pose significant challenges for conventional water treatment. Chechish researchers systematically explored 15 fluorine-free β-cyclodextrin-based nanosponges in binding 17 PFAS [1]. Clear structure–function relationships were identified using sorbent-water distribution coefficients (Ksw) as a performance metric. Notably, the combination of trimethylammonium-functionalized cyclodextrin and hexamethylene diisocyanate cross-linker (AmCD-HMDI) exhibited the highest and broadest binding performance, including exceptional uptake of short-chain compounds, outperforming commercial benchmarks. These findings support further validation and development of the new AmCD-HMDI performance standard for PFAS remediation. More broadly, this work identifies polymer sorbents’ features exhibiting strong and consistent performance across a broad range of PFAS, providing guidance for the design of effective PFAS sorbents.
Fluorine-free sorbent was prepared by Australian researchers: positively charged, green-synthesized β-cyclodextrin polymers (β-CDP+) were studied for the removal of perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) as short- and long-chain PFAS, respectively, from water f2]. Methyl orange (MO) and acid red 1 (AR1), as anionic dyes, were used as proxies to optimize PFAS adsorption conditions. β-CDP+ exhibited high removal efficiencies (>90%) for all pollutants within 15–50 mg/L, reaching equilibrium within 30 min. Maximum adsorption capacities (Qm) were achieved for MO (335 mg/g), AR1 (384 mg/g), PFOA (405 mg/g), and PFBA (378 mg/g). Over 80% PFBA and PFOA removal was maintained in the presence of competing anions, demonstrating the potential of β-CDP+ for simultaneous removal of PFAS, NOM, and anionic dyes. The use of MO and AR1 as proxies was validated by high Spearman’s ρ values (>0.9), reflecting similar adsorption trends to PFAS. The adsorbent’s performance depended on glycidyltrimethylammonium chloride (GTMAC) loading and adsorbent dosage, with optimal conditions at a 1:5 β-CD:GTMAC molar ratio, 0.5 g/L, and pH 7. Adsorption followed the Langmuir isotherm (R2 > 0.98) and pseudo-second-order kinetics (R2 > 0.9). The polymer retained its adsorption performance over five cycles with minimal loss, demonstrating a sustainable strategy for the removal of emerging pollutants.
[1] Pavlína Konopáčová, Christopher J. Hobbs, Martin Stuchlík, Hana Řezanková, Šimon Vojta, Jitka Bečanová, and Michal Řezanka (2026) Structure-Sorption Relationships of Fluorine-Free Cyclodextrin Nanosponges for PFAS Removal. ACS ES&T Water 6 (6), 3759-3768.
DOI: 10.1021/acsestwater.6c00158
[2] Samira Sadeghi, Ahmad Najafidoust, Mark Mullett, Shayan Karimi, Masoumeh Zargar (2026) Green and charge-tuned β-cyclodextrin polymers for efficient removal of PFAS and anionic dyes from water. Journal of Water Process Engineering 84, 109742. https://doi.org/10.1016/j.jwpe.2026.109742.
See also: https://cyclodextrinnews.com/2026/05/04/cds-for-the-removal-of-pfas-a-review/