Boron removal with layered double hydroxide thin-film nanocomposite desalination membrane Liang YingEe abc ,QipengZhao a ,JieGao a ,Chit KaiLim a ,KaiXue d ,Sze YuetChin d ,Sam Fong YauLi be ,Tai-ShungChung af ,Shing BorChen a a Department of Chemical and Biomolecular Engineering, College of Design and Engineering, National University of Singapore, Singapore b Department of Chemistry, College of Humanities and Sciences, National University of Singapore, Singapore, c Chemical Engineering Program, Physical Science and Engineering Division, King Abdullah University of Science and Technology, Saudi Arabia, d Centre of High Field NMR Spectroscopy and Imaging, School of Physical and Mathematical Sciences, College of Science, Nanyang Technological University, Singapore, e NUS Environmental Research Institute, National University of Singapore, Singapore, f Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taiwan The elimination of small and potentially toxic boron species in water is always a significant challenge for conventional membrane technologies. In this study, facile intercalation and functionalization of β-cyclodextrin (CD) onto layered double hydroxides (LDHs) have resulted in the formation of accessible hydroxyl functional groups and anions that exhibit strong sorption and host–guest interaction with boron. Through meticulous molecular design and optimization, the modified LDH possessing the maximum boron adsorption capacity of 96.1mgg −1 was employed to fabricate a polyamide-based thin-film nanocomposite (TFN) membrane with a loading of 0.10wt%. This resultant membrane displayed a high salt rejection and water permeance of 99.4 % and 2.68 LMH bar −1 for brackish water, respectively, which can be attributed to the increased interlayer spacing of 1.67nm and the thinner selective layer. The innovative TFN membrane also achieved a high boron rejection of 82.3 % against brackish water containing 2,000mg L −1 NaCl and 15mg L −1 B at pH 8. This pioneering study provides valuable insights into the design of brackish water reverse osmosis (BWRO) membranes, through the synergistic use of macrocyclic molecules and inorganic layered nanomaterials, that could potentially revolutionize water reuse and boron removal applications. References 1. L.Y. Ee, Q. Zhao, J. Gao, C.K. Lim, K. Xue, S.Y. Chin, S.F.Y. Li, T.-S. Chung, S.B. Chen, Cyclodextrin-modified layered double hydroxide thin-film nanocomposite desalination membrane for boron removal, Chem. Eng. J. 474 (2023), 145723,https://doi.org/10.1016/j.cej.2023.145723. 2. L.Y. Ee, S.Y.R. Chia, K. Xue, S.Y. Chin, C.A.H. Cho, X.Y. Tan, S.F.Y. Li, Hyperbranched nanocellulose enabling rapid boron removal from aqueous environment, Chem. Eng. J. 454 (2023), 140218, https://doi.org/10.1016/j.cej.2022.140218. 3. Q. Zhao, D.L. Zhao, T.-S. Chung, S.B. Chen, In-situ growth of layered double hydroxides (LDHs) onto thin-film composite membranes for enhanced reverse osmosis performance, Desalination 547 (2023), 116235, https://doi.org/10.1016/j. desal.2022.116235. 4. Q. Zhao, D. Zhao, F. Feng, T.-S. Chung, S. Chen, Thin-film nanocomposite reverse osmosis membranes incorporated with citrate-modified layered double hydroxides (LDHs) for brackish water desalination and boron removal, Desalination 527 (2022) 115583, https://doi.org/10.1016/j.desal.2022.115583.
P15
© The Author(s), 2023
Made with FlippingBook Learn more on our blog