Charge‐Gradient Hydrogels Enable Direct Zero Liquid Discharge for Hypersaline Wastewater Management. Issue 24 (8th May 2021)

• Record Type: Journal Article
• Authors: Xie, Wenke; Duan, Jiangjiang; Li, Jia; Qi, Bei; Liu, Rong; Yu, Boyang; Wang, Hui; Zhuang, Xinyan; Xu, Ming; Zhou, Jun
• Is Part Of: Advanced materials. Volume 33:Issue 24(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-08
• Subjects: charge‐gradient hydrogels -- desalination -- membrane distillation -- wastewater management -- zero liquid discharge; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202100141
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Zero liquid discharge (ZLD), which maximizes water recovery and eliminates environmental impact, is an urgent wastewater management strategy for alleviating freshwater shortage. However, because of the high concentration of salts and broad‐spectrum foulants in wastewater, a huge challenge for ZLD is lack of a robust membrane‐based desalination technology that enables direct wastewater recovery without costly pretreatment processes. Here, a paradigm‐shift membrane distillation (MD) strategy is presented, wherein the traditional hydrophobic porous membrane is replaced with a hydrophilic nonporous charge‐gradient hydrogel (CGH) membrane that possesses hypersaline tolerance, fouling/scaling‐free properties, and negligible vapor transfer resistance inside the membrane, simultaneously. Therefore, the CGH‐based MD with high water flux enables direct desalination of hypersaline wastewater (130 g L ‐1 ) containing broad‐spectrum foulants (500 mg L ‐1 ) during continuous long‐term operation (200 h), and this technology paves a promising way to direct ZLD for wastewater management. Abstract : Zero liquid discharge (ZLD), as the ultimate goal of wastewater treatment, is hampered by the lack of robust membrane‐based desalination technologies. A hydrophilic nonporous charge‐gradient hydrogel (CGH) membrane shows high water flux and excellent fouling/scaling‐free properties in membrane distillation, enabling direct and ultrastable desalination of hypersaline wastewater (130 g L −1 ) containing broad‐spectrum foulants (500 mg L −1 ) for 200 h.