Ching Casey, Ling Yuhan, Trang Brittany, Klemes Max, Xiao Leilei, Yang Anna, Barin Gokhan, Dichtel William R, Helbling Damian E
School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA; Cyclopure, Inc., Skokie, IL 60077, USA.
Water Res. 2022 Feb 1;209:117938. doi: 10.1016/j.watres.2021.117938. Epub 2021 Dec 5.
Cyclodextrin polymers (CDPs) are emerging adsorbents with demonstrated potential to remove perfluoroalkyl acids (PFAAs) from water. However, little is known about how the physicochemical properties of different types of CDPs determine PFAA adsorption on CDPs. In this study, we investigated the adsorption performance of 34 CDPs which consist of 14 different crosslinkers and exhibit a wide range of physicochemical properties. The performance metrics included adsorption kinetics, equilibrium adsorption density, and adsorption affinity for six PFAAs. We then used complementary bivariate and multivariate analyses to discover relationships between sixteen measurable physicochemical properties of the CDPs and their performance as adsorbents. We found that: (1) CDPs with a less negative or more positive surface charge will exhibit enhanced adsorption of all types of PFAAs; (2) CDPs with greater porosity and surface area will exhibit enhanced adsorption kinetics for all types of PFAAs; (3) CDPs with greater crosslinker content will exhibit enhanced adsorption of short-chain PFAAs; (4) CDPs containing more hydrophobic crosslinkers will exhibit enhanced equilibrium adsorption density and adsorption affinity for longer-chain PFAAs; and (5) CDPs with smaller particle sizes will exhibit enhanced adsorption kinetics and equilibrium adsorption density for all PFAAs. These insights will enable the further development of CDPs and other novel adsorbents to optimize their performance for removing PFAAs during water and wastewater treatment or groundwater remediation.
环糊精聚合物（CDPs）是一种新兴的吸附剂，已证明具有从水中去除全氟烷基酸（PFAAs）的潜力。然而，对于不同类型的CDPs的物理化学性质如何决定PFAA在CDPs上的吸附，人们了解甚少。在本研究中，我们研究了34种CDPs的吸附性能，这些CDPs由14种不同的交联剂组成，具有广泛的物理化学性质。性能指标包括六种PFAA的吸附动力学、平衡吸附密度和吸附亲和力。然后，我们使用互补的双变量和多变量分析来发现CDPs的16种可测量物理化学性质与其作为吸附剂的性能之间的关系。我们发现：（1）表面电荷负性较小或正性较强的CDPs对所有类型的PFAA的吸附都会增强；（2）孔隙率和表面积较大的CDPs对所有类型的PFAA的吸附动力学都会增强；（3）交联剂含量较高的CDPs对短链PFAA的吸附会增强；（4）含有更多疏水交联剂的CDPs对长链PFAA的平衡吸附密度和吸附亲和力会增强；（5）粒径较小的CDPs对所有PFAA的吸附动力学和平衡吸附密度都会增强。这些见解将有助于进一步开发CDPs和其他新型吸附剂，以优化它们在水和废水处理或地下水修复过程中去除PFAA的性能。
