Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, 611731 Chengdu, China.
Water Res. 2023 Sep 1;243:120348. doi: 10.1016/j.watres.2023.120348. Epub 2023 Jul 12.
Membrane fouling and scaling are two challenges for efficient treatment of hypersaline wastewater, greatly hindering separation performance and operation stability of desalination membranes. In this work, we report a smooth ceramic-based graphene desalination membrane, exhibiting enhanced anti-fouling and anti-scaling ability and operational performance for efficient treatment of both synthetic and real industrial wastewaters, outperforming polypropylene (PP) membrane. For treatment of hypersaline waters containing organic or inorganic substance, we demonstrate that the graphene membrane exhibits more stable water flux and almost complete salt rejection (>99.9%) during constant operation. Enhanced anti-fouling and desalination performance of graphene membrane could be attributed to the lower attractive interaction force with foulant (-4.65 mJ m), lower surface roughness (R = 2.2 ± 0.1 nm) and higher affinity with water than PP membrane. Furthermore, an anti-scaling mechanism enabled by graphene membrane is evidenced, with a highlight on the roles of smooth graphene surface with lower roughness, less nucleation sites and lower binding force with scaling crystals. Importantly, even for industrial petrochemical wastewater, such a graphene membrane also exhibits relatively more stable water flux and promising oil and ions rejection during long-term operation, outperforming PP membrane. This study further confirms a promising practical application potential of robust ceramic-based graphene membrane for efficient treatment of more challenging hypersaline wastewater with complicated compositions, which is not feasible by conventional desalination membranes.
膜污染和结垢是高效处理高盐废水的两大挑战，极大地阻碍了海水淡化膜的分离性能和运行稳定性。在这项工作中，我们报告了一种基于陶瓷的光滑石墨烯海水淡化膜，具有增强的抗污染和抗结垢能力以及运行性能，可高效处理合成和实际工业废水，优于聚丙烯（PP）膜。对于处理含有有机或无机物质的高盐废水，我们证明，在持续运行过程中，石墨烯膜表现出更稳定的水通量和几乎完全的盐排斥（>99.9%）。石墨烯膜具有增强的抗污染和脱盐性能，这归因于与污染物的吸引力相互作用较小（-4.65 mJ m）、表面粗糙度较低（R = 2.2 ± 0.1 nm）和对水的亲和力高于 PP 膜。此外，还证明了石墨烯膜具有抗结垢机制，突出了具有较低粗糙度、较少成核点和与结垢晶体结合力较低的光滑石墨烯表面的作用。重要的是，即使对于石化工业废水，这种石墨烯膜在长期运行过程中也表现出相对更稳定的水通量和有前景的油和离子排斥，优于 PP 膜。这项研究进一步证实了具有强大抗污染能力的坚固陶瓷基石墨烯膜在高效处理具有复杂成分的更具挑战性的高盐废水中具有很大的实际应用潜力，这是传统海水淡化膜无法实现的。
