Self-cleaning catalytic membrane with super-wetting interface for high-efficiency oil-in-water emulsion separation

Abstract

Separation membranes with super-wetting interface can mitigate adhesion between oil and membrane, but fouling still persists and will reduce process efficiency. Here, super-wetting membranes with catalytic performance were fabricated with Fe3O4-loaded attapulgite (FATP) nanofibers as separation layer. The FATP possesses hydrophilic and micro-nano roughness, which can form a hydration layer as a barrier to resist oil fouling. Simultaneously, the FATP serves as a catalyst for the Fenton-like reaction to remove irreversible fouling. During oil-in-water filtration, more than 99.5 % of oil droplets can be rejected, and membrane permeance maintains at 62% of its initial value. After hydraulic cleaning, the permeance recovers to 85%, while the remaining 10.9% permeance can be restored through Fenton-like reaction. In the catalytic process, oil fouling can be degraded into smaller particles and escape from membrane structure. This work prepared an anti-fouling super-wetting membrane and provided insights into the membrane's catalytic mechanism after oil fouling.