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]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA

年份：2024

卷号：329

外文期刊名：SEPARATION AND PURIFICATION TECHNOLOGY

收录：;EI(收录号：20233914812693);WOS:【SCI-EXPANDED(收录号:WOS:001086255000001)】；

基金：This work was supported by the National Natural Science Foundation of China [22075076 & 22208097] . We highly appreciate the collabora-tions with the University of Kentucky NIEHS Superfund center.

语种：英文

外文关键词：Adsorptive membrane; PFAS removal; Removal mechanism; pH-swing regeneration; Water matrix

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 (pK(b): similar to 5.82), the quaternary-ammonium (QA) brushes endowed consistent membrane pore structure and higher isoelectric point (pH(IEP): 11.2 versus 7.5), resulting in a suitable pH-swing adsorption/desorption range towards groundwater conditions. Such QA-grafted membranes (QA loading: 1.1 mmol/g) not only presented >90 % removal of perfluorooctanoic acid (PFOA) at a treatment capacity of 570 L per m(2) of membrane area, 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 treatment capacity of 2,930 L/m(2). The impacts of ionic strength, ionic types, and natural organic matters were evaluated. Overall, the pH-swing strategy is an effective method with high permeability (165.6 L m(-2)h(-1)bar(-1)), stability, and tunable adsorption/regeneration processes.