Recently, oily wastewater has become an urgent cross-regional problem. Membrane technology is considered a sound solution to this crisis. However, membrane fouling causes a sharp decrease in water permeance and service life, which greatly restricts membrane applications. In addition to a few degradable materials, the most severely polluted membranes are burned or buried in the soil, wasting resources and accelerating ecological damage. Inspired by Guandong candy, we reported a novel, facile, and green approach to construct composite polyvinylidene fluoride (PVDF) membranes with stable self-cleaning, anti-oil-fouling, and photocatalytic recovery properties for efficient oil-in-water emulsions separation. Due to the synergistic effect of the superhydrophilic tin dioxide/titanate nanotubes (SnO2/TNTs) and Guandong-candy-inspired electrolessly welding organic-inorganic hybrid colloids, the composite PVDF membrane showed remarkable stability and underwater oil-repellency properties. Accordingly, the composite PVDF membrane achieved excellent water permeance (>2600 L m(-2) h(- 1 )bar(- 1)), superior separation efficiency (>99.6 %), and long-term antifouling performance during soybean oilin-water emulsion separation. More importantly, the composite PVDF membrane exhibited highly efficient selfcleaning and recovery of the PVDF membrane and SnO2/TNTs under visible-light irradiation. Within the framework of green and sustainable concepts, this is a novel reusable idea for the recyclable utilization of commercial PVDF membranes and photocatalytic minerals in oily wastewater purification.

Superhydrophilic/underwater superoleophobic materials for the separation of oil-water emulsions by filtration have received much attention in order to solve the pollution problem of oil-water emulsion. In this paper, a fence-like structure on the surface of CNF/KGM (Konjac Glucomannan) materials by a simple method using CNF instead of metal nanowires was successfully developed based on the hydrogen bonding of KGM and CNF. The resulted organic CNF/KGM materials surface has outstanding superhydrophilic (WCA = 0 degrees) in air and superoleophobicity (OCA >= 151 degrees) in water, which could separate oil-water mixtures with high separation efficiency above 99.14 % under the pressure of the emulsion itself. The material shows good mechanical properties because of the addition of CNF and has outstanding anti-fouling property and reusability. More importantly, the material can be completely biodegraded after buried in soil for 4 weeks since both of KGM and CNF are organic substances. Therefore, it may have a broad application prospect in the separation of oil-water emulsion because of its outstanding separation properties, simply preparation method and biodegradability.