In this study, a mixed matrix polyethersulfone/iron-nickel oxide nanoparticle nanofiltration membrane was prepared by the solution casting technique. Polyvinylpyrrolidone was also used as a membrane pore former in membrane fabrication. The effect of iron-nickel oxide nanoparticles concentration in the casting solution on the membrane structure and performance was investigated. Scanning optical microscopy (SOM) and scanning electron microscopy analysis (SEM), water contact angle, NaCl/Na2SO4 salt rejection, water flux and tensile strength measurements were also carried out in membrane characterization. SOM images showed relatively uniform particle distribution and surface for the prepared membranes. Moreover, SEM images showed that the macro-voids’ size was enhanced in the membrane sub-layer with an increase of additive concentration. Results showed that increasing iron-nickel oxide nanoparticles from 0 to 0.1 wt.% in the membrane matrix caused a decrease in contact angle from 63 to 43° and again increased to 56° by increasing the particles concentration to 1 wt.%. The membrane water flux was enhanced sharply with an increase of nanoparticle concentration up to 0.01 wt.% in the membrane matrix and then decreased slightly at higher additive contents. Salt rejection was generally improved with an increase of nanoparticle concentration. Membrane mechanical strength was initially declined by using iron-nickel oxide nanoparticles up to 0.1 wt.% in the membrane matrix and then increased at higher additive contents. The nanocomposite membranes showed more appropriate antifouling capacity compared to a pristine PES membrane. The effect of feed concentration on membrane salt rejection and water flux was also studied.
