Polycationic liquid modified functional membrane showing good separation performance in dye wastewater treatment

Membrane separation technology is widely used in the treatment of dye wastewater because of its low cost, high separation efficiency, simple operation and no secondary pollution. In this study, a series of blend cellulose acetate (CA) membranes with different compositions were prepared by blending a polycationic liquid synthesized in laboratory with CA. The membranes were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy analysis and the surface properties including the water contact angle, mechanical strength, pure water flux, pore size and zeta potentials were also tested. The hydrophilicity of the membrane was improved by blending more additive. Compared with pure CA membrane, the surface zeta potential value of the modified membrane increased. The maximum pure water flux of the modified membranes was 32.51 L/m2·h. In the experiment of filtering two cationic dyes (acridine yellow hydrochloride and Rhodamine B) with different molecular weights, it is found that the blend modified membrane with optimal performance showed better antifouling performance and higher rejection rate, the flux recovery rates of acridine hydrochloride yellow and Rhodamine B were 93.94% and 87.47%, and the rejection rates were 87% and 76.1%, respectively.