Separation of used automobile oil/water mixture by Nylon 6/ZnO nanoparticles electrospun membrane

Abstract

The separation of water from oily wastewater by using membranes is a big challenge because of serious membrane fouling and low separation efficiency. So, for the first time, Nylon 6 (N6) membranes blended with ZnO nanoparticles with a N6 support layer by the electrospinning technique were fabricated, where the N6 layer enhanced the mechanical strength and ZnO NPs formed a strong barrier on the N6 membrane to reduce membrane pore-clogging. The micron pore size membranes created by hydrophilic ZnO NPs on electrospun Nylon 6 fiber–matrix structures contributed to the hydrophilicity and fouling resistance of the membranes. The optimal quantities of ZnO NPs and N6 in the electrospun membranes were 2.5 and 40 w.t%, respectively, for achieving the desired specific flux of 215.14 LMH/bar over 3 h when using a 0.1% v/v oil/water influent. Up to 90% of oil, chemical oxygen demand, turbidity, total dissolved solids, and total suspended solids were removed to fulfill discharge requirements. The presence of ZnO NPs in the N6 membrane also exhibited excellent anti-fouling properties with the flux recovery ratio of 52.5 % and water flux of 405.6 LMH/bar, which was much better than those of a pristine N6 membrane, indicating the microfiltration membranes developed in this study were reasonably resistant to fouling to ensure high effluent water quality and the fabricated N6/ZnO NPs membrane is feasible in treating oil-containing wastewater.