Discarded Cigarette Butts Regenerated Superhydrophilic/ Underwater Superoleophobic Chitosan–Cellulose Membrane for Oil/ Water Emulsion Separation

Abstract

With the rapid development of the chemical industry, oil/ water emulsion separation is receiving global attention. It is particularly important to find a low-cost, convenient, economical and environmentally friendly method to prepare superhydrophilic/ underwater superoleophobic membranes for oil/ water emulsion separation. In this paper, discarded cigarette butts were used as raw materials, combined with chitosan to form a superhydrophilic/ underwater superoleophobic membrane through a phase inversion method. The performance of CA/CS membrane is controlled by adjusting the ratio of cellulose acetate and chitosan. The cigarette butts are washed in ethanol solution to remove impurities to obtain cellulose acetate, and then chitosan and polyvinylpyrrolidone (PVP) are added to build the micro–nano structure on the surface of the membrane. The prepared CA/CS composite membrane was superhydrophilic/ underwater superoleophobic. For the oil-in-water emulsion, the filtrate of the CA/CS membrane can hardly see the oil droplets through electron microscope. CA/CS membrane has a higher emulsion permeation flux (more than 340 L m[Formula: see text] h[Formula: see text] and a higher separation efficiency (more than 97.1%). In addition, the membrane has good reusability within 10 cycles. This method can reduce the harm of cigarette butts to nature and can also be used for oil–water separation. The method of turning discarded cigarette butts into treasure is worthy of social advocacy.