Superhydrophilic bacterial cellulose membranes efficiently separate oil-in-water emulsions

Bacterial cellulose (BC) derived from Nata de coco waste was modified and used to develop environmentally friendly superhydrophilic BC membranes with highly efficient oil removal properties. Spherical SiO2 nanoparticles were synthesized by hydrolyzing tetraethoxysilane (TEOS) in the presence of ammonia and deposited on the surface of the BC membranes to improve their surface roughness and wettability. The modified BC membranes show an efficient water flux ranging from 142 +/- 39 to 195 +/- 24 Lm(-2) h(-1) MPa-1 for oil-in-water emulsions and a separation efficiency of up to 99%. The membranes exhibit good mechanical properties, excellent reusability with high efficiency about 96% after several separation cycles and also good antifouling properties with a higher flux recovery rate (FRR) and reversible fouling ratio (R-r), and a lower irreversible fouling ratio (R-ir). Furthermore, the obtained membranes show stability in severe conditions. Thus, the membrane has considerable promise for practical application in the treatment of emulsion wastewater.