Disc-tube graphene oxide membranes for efficient and scalable organic removal from saline wastewater

Advanced treatment of high-salinity organic wastewater from the fine chemical industry is a critical environmental challenge. Graphene oxide (GO) membranes show promise for separating organic compounds and inorganic salts, but their industrial application has been limited by issues with scalability, performance stability, and fouling control. To overcome these barriers, we developed a disc-tube graphene oxide (DTGO) membrane system by optimizing preparation parameters, stacking membrane discs, and integrating in situ fouling mitigation. Our optimized DTGO membrane exhibited exceptional durability during 280-h cross-flow filtration, maintaining stable water flux (∼60 LMH), high rejection of neutral and negatively charged organics (>90 %), and minimal salt retention (<7 %). The DTGO membrane, which can be easily scaled up through disc stacking, showed superior antifouling performance, with a lower flux decline (12.5 %) and irreversible fouling (33 %), compared with GO membranes on other substrates and organic membranes in simulated wastewater. The introduction of hydroxyl radicals further increased the number of hydroxyl functional groups on the membrane surface, enhancing the formation of a protective hydrated layer and reducing flux decline by over 70 % (flux decline 3.5 %). This work demonstrates the potential for large-scale GO membrane deployment, which offers a cost-effective and environmentally friendly solution for sustainable wastewater treatment and resource recovery.