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The ubiquitous presence and persistence of per‐ and polyfluoroalkyl substances (PFAS) in the environment have raised concerns in the scientific community. Current research efforts are prioritizing effective PFAS remediation through novel sorbents with orthogonal interaction mechanisms. Recognized sorption mechanisms between PFAS and sorbents include hydrophobic, electrostatic, and fluorine‐fluorine interaction. The interplay of these mechanisms contributes significantly to improved sorption capacity and selectivity in PFAS separations. In this study, a primary/secondary amine‐functionalized polystyrene‐divinylbenzene (Sepra‐WAX) polymer was modified to create a fluorinated WAX resin (Sepra‐WAX‐KelF‐PEI). The synthesis intermediate (Sepra‐WAX‐KelF) was also tested to assess the improvement of the final product (Sepra‐WAX‐KelF‐PEI). The adsorption capacity of Sepra‐WAX, Sepra‐WAX‐KelF, and Sepra‐WAX‐KelF‐PEI, and their interactions with PFAS were evaluated. The effect of pH, ionic strength, and organic solvents on PFAS sorption in aqueous solution was also investigated. The sorbents showed varied adsorption capacities for perfluorooctanoic acid, perfluoropentanoic acid, perfluoro‐n‐decanoic acid, and hexafluoropropylene oxide dimer acid, with the average extraction capacity of the four analytes being Sepra‐WAX‐KelF‐PEI (523 mg/g) > Sepra‐WAX (353 mg/g) > Sepra‐WAX‐KelF (220 mg/g). Sepra‐WAX‐KelF‐PEI provided the highest adsorption capacity for all analytes tested, proving that the combination of electrostatic and hydrophobic/fluorophilic interactions is crucial for the effective preconcentration of PFAS and its future applications for PFAS remediation from aqueous solutions.
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This content will become publicly available on December 1, 2026
Per- and Polyfluoroalkyl Carboxylic Acids Mixture Adsorption on Surfactant-Modified Granular Activated Carbon: Mechanisms and Competitive Effects
Per- and polyfluoroalkyl substances (PFAS) are a type of emerging contaminant associated with significant health risks, such as carcinogenicity, endocrine disruption, and immunotoxicity. The persistent nature and widespread occurrence of PFAS, particularly perfluoroalkyl carboxylic acids such as perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA), necessitate the development of efficient remediation strategies. In this study, granular activated carbon (GAC) was modified with cetyltrimethylammonium chloride (CTAC) to enhance the adsorption capacity of PFAS. The surface morphology and physicochemical properties of unmodified and modified GAC (MGAC) were characterized using scanning electron microscopy and Brunauer–Emmett–Teller analysis, revealing significant surface and pore structure alterations following CTAC modification. Batch adsorption experiments demonstrated that MGAC exhibited superior adsorption capacities for PFOA (93.18 mg/g) and PFNA (130.94 mg/g) compared with unmodified GAC (90.53 mg/g and 103.71 mg/g, respectively). The observed increase in adsorption capacity is attributable to enhanced electrostatic and hydrophobic interactions facilitated by the quaternary ammonium groups and hydrophobic alkyl chains of CTAC. However, competitive adsorption tests indicated a reduction in PFNA adsorption efficiency, suggesting that PFAS cooccurrence affects adsorption dynamics. Adsorption isotherms were best described by the Langmuir model, indicating monolayer adsorption on homogeneous surfaces. The findings underscore the efficacy of surfactant-modified GAC in enhancing PFAS removal from aqueous environments and provide critical insights into the mechanisms governing PFAS adsorption under single and mixed-species scenarios. This study advances the development of adsorbents for PFAS remediation, addressing the challenges of complex environmental matrices and cooccurring PFAS species.
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- Award ID(s):
- 2418751
- PAR ID:
- 10680818
- Publisher / Repository:
- Sage Journals
- Date Published:
- Journal Name:
- Environmental Engineering Science
- Volume:
- 42
- Issue:
- 12
- ISSN:
- 1092-8758
- Page Range / eLocation ID:
- 522 to 532
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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