Department of Chemical and Biomolecular Engineering, Clarkson University, Potsdam, New York 13699, United States.
Center for Air and Aquatic Resources Engineering & Science, Clarkson University, Potsdam, New York 13699, United States.
Environ Sci Technol. 2021 Nov 16;55(22):15162-15171. doi: 10.1021/acs.est.1c03974. Epub 2021 Oct 29.
Harmful per- and polyfluoroalkyl substances (PFAS) are ubiquitously detected in aquatic environments, but their remediation remains challenging. Metal-organic frameworks (MOFs) have been recently identified as an advanced material class for the efficient removal of PFAS, but little is known about the fundamentals of the PFAS@MOF adsorption process. To address this knowledge gap, we evaluated the performance of 3 different MOFs for the removal of 8 PFAS classes from aqueous film-forming foam-impacted groundwater samples obtained from 11 U.S. Air Force installations. Due to their different pore sizes/shapes and the identity of metal node, MOFs NU-1000, UiO-66, and ZIF-8 were selected to investigate the role of MOF structures, PFAS properties, and water matrix on the PFAS@MOF adsorption process. We observed that PFAS@MOF adsorption is (i) dominated by electrostatic and acid-base interactions for anionic and non-ionic PFAS, respectively, (ii) preferred for long- over short-chain PFAS, (iii) strongly dependent on the nature of PFAS head group functionality, and (iv) compromised in the presence of ionic and neutral co-contaminants by competing for ion-exchange sites and PFAS binding. With this study, we elucidate the PFAS@MOF adsorption mechanism from complex water sources to guide the design of more efficient MOFs for the treatment of PFAS-contaminated water bodies.
有害的全氟和多氟烷基物质（PFAS）在水生环境中普遍存在，但它们的修复仍然具有挑战性。金属有机骨架（MOFs）最近被确定为一种用于有效去除 PFAS 的先进材料类别，但对于 PFAS@MOF 吸附过程的基础原理知之甚少。为了解决这一知识空白，我们评估了 3 种不同 MOFs 对从 11 个美国空军设施获得的受水性成膜泡沫影响的地下水样品中 8 种 PFAS 类别的去除性能。由于它们的孔径/形状不同和金属节点的不同，选择 MOF NU-1000、UiO-66 和 ZIF-8 来研究 MOF 结构、PFAS 特性和水基质对 PFAS@MOF 吸附过程的作用。我们观察到，PFAS@MOF 吸附是（i）分别由阴离子和非离子 PFAS 的静电和酸碱相互作用主导，（ii）对长链 PFAS 的偏好大于短链 PFAS，（iii）强烈依赖于 PFAS 头基官能团的性质，（iv）在存在离子和中性共污染物时，由于争夺离子交换位点和 PFAS 结合而受到影响。通过这项研究，我们阐明了从复杂水源到指导设计更高效的 MOFs 来处理受 PFAS 污染的水体的 PFAS@MOF 吸附机制。
