Concurrent Oil and Water Recovery through Emulsions Separation by Heterogeneous Wettable Nanofibrous Membrane

Concurrent oil and water recovery from emulsions has attracted significant attention for the zero-discharge treatment of oily wastewater. Coalescence demulsification mechanism offers promising recovery of both oil and water phases, ultimately realizing zero-discharge of oily wastewater. However, fouling caused by oil and other contaminants is still one of the toughest challenges for coalescence demulsification membranes. This work reports a heterogeneous wettable nanofibrous membrane with welded nanofibers, which enables durable oil-water separation and concurrent oil and water recovery. The welded heterogeneous wettable channels ensure robust separation and recovery stability through a feedback loop of capture-aggregation-release of oil phase. Under continuous flow-through separation, oil and water recovery reached up to 67.5% and 99.6%, respectively with purities close to 99.9%. This study provides new insights into oil-water recovery from emulsions via coalescence demulsification and advances the potential practical applications of this approach in the zero-discharge treatment of oily wastewater.