Hybrid membranes made from industrial waste for the separation of oil emulsions

Abstract

Abstract The development of sustainable membranes from polymer waste is a promising strategy for wastewater treatment. This study investigated the effect of zinc oxide (ZnO) incorporation on recycled polyamide 66 (PA66) membranes prepared by the phase inversion method for oily emulsion separation. Membranes were characterized by atomic force microscopy, porosity, water absorption, pore size, contact angle, and permeation tests. ZnO promoted structural modifications, increasing roughness (140.87 nm), water absorption (76.6%), porosity (60.5%), and mean pore radius (1.85 µm) compared with pure PA66. The membrane containing 3 wt.% ZnO exhibited the highest stabilized water permeate flux (159.82 L.m-2.h-1). All membranes achieved color and turbidity removals of up to 99.88% and oil rejection above 95%, producing permeates that complied with current discharge regulations. These results demonstrate that recycled PA66/ZnO hybrid membranes are promising, sustainable candidates for efficient oily wastewater treatment.