Evaluating the performance of different nano-enhanced ultrafiltration membranes for the removal of organic pollutants from wastewater

Abstract Vermiculite nanoparticles (Verm NPs) incorporated polyvinylidene fluoride (PVDF) flat sheet membrane was prepared using phase inversion method and compared with aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), and copper oxide (CuO) NPs incorporated PVDF. The nanocomposites PVDF membranes were modified via an ultrathin coating surface layer of a dilute poly(vinyl alcohol) (PVA) aqueous solution in order to provide sufficient hydrophilicity, rejection, and a reduced surface roughness. The characterizations of pure PVDF, PVA/PVDF, PVA/PVDF/Al 2 O 3 (M1), PVA/PVDF/SiO 2 (M2), PVA/PVDF/CuO (M3) and PVA/PVDF/Verm (M4) membranes were performed using FTIR, Contact angle, and SEM. The membrane performances were evaluated and antifouling properties of the synthesized membranes were examined via numerous fouling/washing series using feed solutions of bovine serum albumin (BSA) such as a potential foulant. The highest permeate flux obtained with a modified ultrafiltration technique was in the order of Verm (628.7)> Al 2 O 3 (598) 2 (590)> CuO (585 L/m 2 ·h) and the humic acid (HA) rejection was in order of Verm (94.56)> Al 2 O 3 (91.7)> SiO 2 (89)> CuO (88.3%) based on an optimum concentration of 0.2, 0.3, 0.1, 0.2 wt.%. The results clearly showed that the incorporation of Verm NPs was favorable to the enhancement of antifouling properties, membrane performances and the mechanical properties compared to other membranes at the identical condition. The synthesized PVA/PVDF membrane and the nanocomposite membranes were used for the removal of four different types of dyes, i.e. Malachite green (MG), Methylene blue (MB), Congo red (CR) and Safranin O (SO) from aqueous solution as examples for organic wastewater treatment.