Designing of bacterial cellulose-based superhydrophilic/underwater superoleophobic membrane for oil/water separation

The oil/water (o/w) separation is a global challenge because of the increasing water contamination by oil spill accidents, and oil-containing wastewater produced by food, textile, and petrochemical industries. In this study, we have developed bacterial cellulose (BC) based superhydrophilic/underwater superoleophobic (SUS) membrane for o/w separation. The membrane was designed through a facile method by blending BC nanofibers with silica microparticles (SiO2-MPs), which was further modified by bio-inspired polydopamine (PDA) coatings. The composite membrane exhibited SiO2-MPs dependent o/w separation with a high separation efficiency of >99.9 % and a high flux rate of ∼10,660 Lm−2 h-1 while applying a small negative pressure (0.3−0.5 bar). The membrane with different content of SiO2-MPs also showed the potential to separate oil-in-water emulsion with the highest oil rejection of 98.2 % and the highest flux rate of ∼1250 Lm−2 h-1 on an ultra-low pressure <0.1 bar. Moreover, the membrane showed antifouling properties, recyclability, and stability in harsh conditions.