Facile and efficient synthesis of polyacrylonitrile-based functional fibers and its sorption properties of perfluorooctane sulfonate and perfluorooctanoate

Polyacrylonitrile fibers-derived functional fibers (GTPANFs) were successfully prepared, and the preparation conditions were studied using the Box-Behnken response surface methodology (RSM). After numerical optimization, the performances of GTPANFs as a segregative adsorbent for removing perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) were evaluated. The structural and surface properties of GTPANFs were characterized using SEM, XPS, FTIR, N-2 sorption-desorption analysis and zeta potential. The sorption process of PFOS and PFOA on GTPANFs followed the pseudo-second-order kinetics, and the Freundlich model well described the sorption equilibrium experiments. The maximum sorption capacities of PFOS and PFOA were 2.78 mmol/g and 2.49 mmol/g respectively, much better than some commercial and natural adsorbents. Little impact on the removal performance in a wide solution pH range of 2-10, and high sorption capacities with coexisting anionic sulfate and hexavalent chromium were observed. Based on batch experiments and analysis of characterization above, the sorption mechanisms including anion exchange, electrostatic interactions and hydrophobic interactions were speculated, and hemi-micelles and micelles might form onto the surface of GTPANFs. Moreover, the GTPANFs had shown excellent performance of regeneration with the mixture of CH3OH and NaCI. (C) 2017 Elsevier B.V. All rights reserved.