Facile preparation of attapulgite nanofiber membrane for efficient separation of high-viscosity oil-in-water emulsions

Abstract

Membrane separation technology is an ideal choice for wastewater treatment due to its low energy consumption and cost. However, membrane separation is limited by easy fouling and low separation efficiency. Therefore, the preparation of membranes with outstanding anti-fouling properties and stable flux is the key to address this problem. Herein, attapulgite (APT) coated polyacrylonitrile (PAN) nanofiber (ACPN) membrane was fabricated through electrospinning and vacuum-filtration assembly. The as-prepared ACPN membrane with micro/nano multi-layer structure exhibited excellent underwater superoleophobicity. The ACPN membrane can be employed to effectively separate a range of surfactant-stabilized oil-in-water emulsions, even high-viscosity crude oil-in-water emulsions with separation efficiency higher than 99.4%. Moreover, after 15 cycles of reusability, the membrane still displayed outstanding separation efficiency and stable permeation flux. Surprisingly, the prepared membrane was also proved to have superior mechanical stability and anti-oil fouling performance. Most importantly, the robust mechanical and chemical stability makes the antifouling ACPN membrane exhibiting prospective potential in the remediation of wastewater containing crude oil, which making it a competitive candidate in oil-water separation. Underwater superoleophobic APT coated PAN nanofiber membrane (ACPN) was employed to effectively separate oil-in-water micro-nanoscale emulsions. • A facile method is employed to prepare nanofiber membranes for separating oil-in-water emulsions. • The ACPN nanofiber membrane with superamphiphilicity/underwater superoleophobicity. • The ACPN membrane can be employed to effectively separate highly viscous crude oil-in-water emulsion and the separation efficiency is higher than 99.4%. • The ACPN nanofiber membrane demonstrated excellent chemical stability, and the separation efficiency remains at 99.3% even after 15 cycles.