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

Abstract

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 SnO 2 nanosheet-wrapped mesh membrane was reported to separate viscous edible oil from food waste leachate for the first time. The nanosized SnO 2 nanosheet coating by one step hydrothermal process endows the copper mesh membrane with a superhydrophilic and underwater−oil contact angle above 158°d ue to the combining the hierarchical structure with strong hydration ability of SnO 2 . Thanks to its strong hydration ability, the SnO 2 nanosheets exhibit underwater antioil-fouling and antibio-fouling properties for efficient viscous food waste leachate separation. The resulting superwetting and antifouling properties enabled the SnO 2 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 SnO 2 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.