Stable Zr-Based Metal–Organic Framework Nanoporous Membrane for Efficient Desalination of Hypersaline Water

• Published in: Environmental science & technology 2021-11, Vol.55 (21), p.14917-14927
• Main Authors: Li, Haotian, Fu, Mao, Wang, Shi-Qiang, Zheng, Xiangyong, Zhao, Min, Yang, Fenglin, Tang, Chuyang Y, Dong, Yingchao
• Format: Article
• Language: English
• Subjects: Desalination; Harsh environments; Interlayers; Membranes; Metal-organic frameworks; Mullite; Pervaporation; Stability; Substrates; Thickness; Titanium dioxide; Treatment and Resource Recovery; Water treatment; Zeolites; Zirconium
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.1c06105

Treatment of hypersaline waters is a critical environmental challenge. Pervaporation (PV) desalination is a promising technique to address this challenge, but current PV membranes still suffer from challenging issues such as low flux and insufficient stability. Herein, we propose in situ nanoseeding followed by a secondary growth strategy to fabricate a high-quality stable metal–organic framework (MOF) thin membrane (UiO-66) for high-performance pervaporation desalination of hypersaline waters. To address the issue of membrane quality, a TiO2 nano-interlayer was introduced on coarse mullite substrates to favor the growth of a UiO-66 nanoseed layer, on which a well-intergrown UiO-66 selective membrane layer with thickness as low as 1 μm was finally produced via subsequent secondary growth. The PV separation performance for hypersaline waters was systematically investigated at different salt concentrations, feed temperatures, and long-term operation in different extreme chemical environments. Besides having nearly complete rejection (99.9%), the UiO-66 membrane exhibited high flux (37.4 L·m–2·h–1) for hypersaline waters, outperforming current existing zeolite and MOF membranes. The membrane also demonstrated superior long-term operational stability under various harsh environments (hypersaline, hot, and acidic/alkaline feed water) and mild fouling behavior. The rational design proposed in this study is not only applicable for the development of a high-quality UiO-66 membrane enabling harsh hypersaline water treatment but can also be potentially extended to other next-generation nanoporous MOF membranes for more environmental applications.