文献类型：期刊文献

英文题名：Ph-Swing Membrane Adsorption of Perfluoroalkyl Substances: Anion-Exchange Brushes and Water Chemistry

作者：Wan, Hongyi[1]; Fang, Fumohan[1]; Shi, Ke[1]; Yi, Zhiyuan[1]; Lei, Linfeng[1]; Li, Siyao[1]; Mills, Rollie[2]; Bhattacharyya, Dibakar[2]; Xu, Zhi[1]

机构：[1] School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY, 40506, United States

年份：2023

外文期刊名：SSRN

收录：EI(收录号：20230138515)

语种：英文

外文关键词：Adsorption - Amines - Electrostatics - Grafting (chemical) - Hydrophobicity - Ion exchange - Membranes - Zeta potential

摘要：The pH-swing strategy, aiming for effective removal, high flux, and facile regeneration, was designed to address emerging trace contaminants, namely perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Quaternary-ammonium (QA) and tertiary-amine (TA) brushes were grafted onto the membrane, allowing for pH-responsive swell/collapse transformation and/or zeta potential switching. The adsorption is driven by synergetic electrostatic and hydrophobic interactions, as demonstrated by the sharp decline in removal efficiency with reduced zeta potential and the greater maximum adsorption capacity of the more hydrophobic species (0.65 and 0.44 mmol/g for PFOS and PFOA, respectively). Owing to its higher isoelectric point (pHIEP = 11.2), the QA-grafted membranes presented over 92% and 97% removal of PFOA and PFOS, respectively, at neutral pH. Over 97% of PFOA was desorbed at pH 12.5 and 5% methanol as the electrostatic repulsion (pH > pHIEP) surpassed the hydrophobic forces. After three pH-swing cycles, a total PFOA removal of 82.4% was achieved with a treatment capacity of 2930 L per m2 of membrane. The impacts of water ionic strength, ionic types, and natural organic matters were also evaluated. Overall, the pH-swing strategy is an effective method with high permeability (165.6 L m-2h-1bar-1), stability, and tunable adsorption/regeneration processes under mild conditions. ? 2023, The Authors. All rights reserved.