LAUSR

Abstract Synthesized photocatalytic multilayer adsorptive membranes were employed as a way to photo-reduction of chromium(VI) and discoloration of methylene blue (MB). The prepared nanoparticle and membranes were analyzed by FTIR, PL, XRD, FESEM, EDX and contact angle analyses. Batch and dynamic tests were done to evaluate the prepared membrane removal performance in two-modes of irradiation. ZnO and its doped form were used as the adsorbents on the membrane surface. To our amazement, the morphology of ZnO nanoparticles was changed from nanorods shape to nanospheres after nitrogen doping. The maximum adsorption capacity with M.N‒ZnO (PES + Chitosan + nitrogen-doped ZnO) was obtained about 1.99 (mg Cr/g) and 2.19 (mg MB/g) under UV irradiation in the static test. The maximum permeation flux ratio was obtained for M.ZnO membrane (PES + Chitosan + undoped ZnO) which was 213.08 L/m2 h and 256.5 L/m2 h for Cr and MB filtration, respectively. The best performance in Cr rejection (about 99%) belonged to M.N‒ZnO in the continuous filtration process. Achieving the equilibrium point after 5 min in continuous filtration was related to the high specific surface area of the photocatalytic adsorbent. The obtained data from dynamic tests were fitted by Yan's empirical model.