Cationically Modified PVA-Based Electrospun Nanofiber Membrane for Adsorptive PFAS Removal from Water

Per- and polyfluoroalkyl substances (PFAS), a diverse range of anthropogenic organic compounds, pose significant concerns to society due to their potential harmful impacts on human health and ecosystems. While there are other methods for removing PFAS from water, adsorption remains a viable and efficient option. The present research reports an adsorptive nanofiber membrane prepared through electrospinning in the presence of poly-(vinyl alcohol) (PVA) and a cationic surfactant, cetyltrimethylammonium chloride (CTAC), blended solution. This modified PVA membrane was observed to achieve nearly 100% capture of all 10 target PFAS, each at 10 μg/L in deionized water. The pseudo-second-order model most accurately represented the adsorption kinetics, characterized by rapid adsorption (within 60 s). The Toth isotherm model effectively fitted the isotherm data, indicating that the adsorption of PFAS onto the membrane involved complex interactions. The hypothesized adsorption mechanisms, including electrostatic and hydrophobic interactions, were validated through detailed adsorption kinetics, isotherms, thermodynamic analyses, and physicochemical characterization. Remarkably, the performance of the modified system remained unaffected by variations in solution pH and natural organic matter, while being slightly affected by ionic strength, with 90-100% removal effectiveness of PFAS in stormwater. This work highlights the significance of electrospun nanofiber membrane-based adsorbents for the efficient removal of PFAS from real water.