Oral Presentation Royal Australian Chemical Institute National Congress 2026

Green and charge-tuned β-cyclodextrin polymers for efficient removal of PFAS and anionic dyes from water (136810)

Samira Sadeghi 1 , Ahmad Najafidoust 2 , Mark Mullett 3 , Shayan Karimi 4 , Masoumeh Zargar 5
  1. School of Engineering, Edith Cowan University, Joondalup, WA, Australia
  2. School of Engineering, Edith Cowan University, Joondalup, WA, Australia
  3. The Water & Carbon Group, Brisbane, QLD, Australia
  4. The Water & Carbon Group, Brisbane, QLD, Australia
  5. School of Engineering, Edith Cowan University, Joondalup, WA, Australia

Water contamination by per- and polyfluoroalkyl substances (PFAS) poses a major environmental challenge due to their persistence. This study evaluates positively charged, green-synthesized β-cyclodextrin polymers (β-CDP⁺) for the removal of perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) as short- and long-chain PFAS, respectively, from water. 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.