Enhanced flux and fouling resistance forward osmosis membrane based on a hydrogel/MOF hybrid selective layer

• Published in: Journal of colloid and interface science 2021-03, Vol.585, p.158-166
• Main Authors: Fu, Wenying, Chen, Jinghu, Li, Chengyun, Jiang, Lingchang, Qiu, Ming, Li, Xi, Wang, Yangang, Cui, Lifeng
• Format: Article
• Language: English
• Subjects: Antifouling; Forward osmosis; Poly (vinyl alcohol); Polydopamine; ZIF-8
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2020.11.092

[Display omitted] Although forward osmosis (FO) technology has been widely adopted for water treatment, it still faces great challenges, including low permeability and fouling problem. Herein, a novel forward osmosis membrane was developed with a stable, uniform and defect-free polyvinyl alcohol/polydopamine coated zeolitic imidazolate framework (PVA/PDA@ZIF-8) hybrid selective layer to simultaneously enhance its transport property and fouling resistance. The prepared FO membrane exhibits improved water flux without losing the selectivity, since the PDA@ZIF-8 provide additional preferential passageway for water transporting while hinder the diffusion of salt. The optimized membrane shows a higher water flux than pristine PVA membrane (14.2 vs. 8.7 L m−2 h−1 in FO mode, 24.3 vs. 14.8 L m−2 h−1 in PRO mode) with a reasonable selectivity considering as Js/Jw value (0.44 vs. 0.4 g L−1 in FO mode, 0.38 vs. 0.33 g L−1). Moreover, the dynamic fouling experiments with organic foulants (protein and polysaccharide) indicate that the prepared membrane exhibits strong antifouling property and excellent permeation recovery ability (>95.0%) due to the optimized surface property. This study opens a new avenue for treatment wastewater by developing a forward osmosis membrane based on a hydrogel/MOF hybrid selective layer.