Alginate-based nanofibrous membrane with robust photo-Fenton self-cleaning property for efficient crude oil/water emulsion separation

The superhydrophilic/underwater superoleophobic filtration membranes with robust anti-oil-fouling performance have aroused extensive research enthusiasm for oily wastewater treatment. However, it is inevitable that this kind of anti-fouling membrane will be contaminated when facing high-viscosity crude oil. In this work, green tannic acid (TA) was introduced in sodium alginate (SA) nanofibrous membrane (NFM) to form stable TA-Fe(iii) complexes via coordination reaction. Then, a layer of rough beta-FeOOH nanoparticles was uniformly constructed on the surface of the nanofiber via in situ mineralization. The obtained SA/TA/beta-FeOOH NFM displayed outstanding underwater superoleophobic and anti-crude oil-fouling performance. Moreover, the SA/TA/beta-FeOOH NFM exhibited high separation efficiency (99.64%) and flux (1899 & PLUSMN; 251 L m(-2)h(-1)) for crude oil-in water emulsion. In addition, SA/TA/beta-FeOOH NFM with fascinating photo-Fenton self-cleaning performance can degrade pollutants adsorbed on the membrane surface. These surprising advantages endow our SA/TA/beta-FeOOH NFM have promising prospects in complex oily wastewater treatment.

Automated summary

In this study, a nanofibrous membrane with stable TA-Fe(iii) complexes and rough beta-FeOOH nanoparticles was developed, which displayed outstanding underwater superoleophobic and anti-crude oil-fouling performance. The membrane also exhibited high separation efficiency and flux for crude oil-in water emulsion. Furthermore, the membrane showed fascinating photo-Fenton self-cleaning performance, degrading pollutants adsorbed on the membrane surface. These advantages make it promising for complex oily wastewater treatment.