文献类型：期刊文献

英文题名：Ph-Swing Membrane Adsorption of Perfluoroalkyl Substances: Anion-Exchange Brushes and Role of 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：20230169881)

语种：英文

外文关键词：Amines - Groundwater - Hydrophobicity - Ion exchange - Ionic strength - Membranes - Pore structure

摘要：The pH-swing membrane adsorption, aiming for effective removal, high membrane permeability, and facile regeneration, was developed to remediate emerging perfluoroalkyl contaminants. Compared to the collapse transformation of deprotonated tertiary-amine brushes at neutral pH (pKb: ~5.82), the quaternary-ammonium (QA) brushes endowed consistent membrane pore structure and higher isoelectric point (pHIEP: 11.2 versus 7.5), resulting in a suitable pH-swing adsorption/desorption range towards groundwater conditions. Such QA-grafted membranes not only presented >90% removal of perfluorooctanoic acid (PFOA) at a bed volume of 5,700 (pH 7.8, QA loading: 1.1 mmol/g), but also enabled effective membrane regeneration that >97% desorption was achieved at pH 12.5 and 5% methanol. The remediation is driven by synergetic electrostatic and hydrophobic interactions, as demonstrated by (1) the zeta-potential dependent removal performance and (2) the greater maximum adsorption capacity towards the more hydrophobic perfluorooctane sulfonate than PFOA (Qm: 0.65 mmol/g and 0.44 mmol/g, respectively). Within three pH-swing adsorption/regeneration cycles, a total PFOA removal of 82.4% was achieved with a bed volume of 29,300. The impacts of 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. ? 2023, The Authors. All rights reserved.