Inorganic Antifouling SnO₂ Nanosheet-Coated Mesh for Effective Separation of Viscous Oils from Food Waste Leachate

Viscous edible oil in kitchen wastewater poses extensive environmental concerns; however, the treatment of food waste leachate remains still a challenge due to its high viscosity at room temperature and complex composition. In this work, a SnO2 nanosheet-wrapped mesh membrane was reported to separate viscous edible oil from food waste leachate for the first time. The nanosized SnO2 nanosheet coating by one step hydrothermal process endows the copper mesh membrane with a superhydrophilic and underwater-oil contact angle above 158 degrees due to the combining the hierarchical structure with strong hydration ability of SnO2. Thanks to its strong hydration ability, the SnO2 nanosheets exhibit underwater antioil-fouling and antibio-fouling properties for efficient viscous food waste leachate separation. The resulting superwetting and antifouling properties enabled the SnO2 nanosheet-coated mesh to quickly remove viscous edible oils with a high permeate flux of 8450 L m(-2) h(-1) and oil content in the filtrate below 50 ppm. The underlying mechanism is provided and revealed by density functional theory calculation. Moreover, importantly, the SnO2 nanosheet-coated mesh exhibits superior chemical stability and stable separation capacity after 20 cycles. Therefore, the aforementioned features suggest the promising potential for addressing large-area oily wastewater.