Fabrication of new cellulose acetate blend imprinted membrane assisted with ionic liquid ([BMIM]Cl) for selective adsorption of salicylic acid from industrial wastewater

Highly selective cellulose acetate (CA) blend imprinted membranes for salicylic acid (SA) was prepared by using phase inversion technique with sulfonated polysulfone (SPS) as a functional polymer, polyethylene glycol-4000 (PEG 4000) and ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the additives. The membranes were characterized by several techniques including SEM, Raman, contact angle, membrane flux, and SA adsorption-desorption techniques. The SEM micrographs showed that the cross-sectional morphology of CA membranes was affected by polymer blend composition and applications of additives. Compared with the pure CA membrane the CA/SPS(90/10) + [BMIM]Cl membranes showed low contact angle, high membrane flux, strong adsorption capacity and high permeation selectivity. The experimental data of adsorption kinetic for CA/SPS(90/10) + [BMIM]Cl were well fitted to the pseudo-second-order kinetic model using multiple regression analysis. The selectivity coefficients of CA/SPS(90/10) + [BMIM]Cl-MIM for SA in relation to competition analogs p-hydroxybenzoic acid (p-HB) and phenol were 5.8549 and 5.9062, respectively, which suggested that CA/SPS(90/10) + [BMIM]Cl-MIM had high selectivity and binding affinity for the template SA. Overall results suggest that [BMIM]Cl can be considered as an effective additive for CA imprinted membranes in the treatment of SA-contained water.