Sustainable <scp>PAN</scp> / <scp>PLA</scp> blend membranes with green nanoparticles for efficient oil–water separation

Abstract This study develops ultrafiltration membranes using a combination of polyacrylonitrile (PAN) and polylactic acid (PLA), modified with green nanoparticles (NPs) derived from potato peel waste (PPW) for oily wastewater treatment. We fabricate the PAN/PLA/PPW membranes by phase reversal technology and characterized them using various techniques. This work investigates the effects of adding green nanoparticles (PPW) (0.015%–0.08%) on membrane properties. At an optimal concentration of 0.05% by weight, the membrane exhibits a significant performance improvement: the water flow rate increases to 1012.7 from 524.3 L/m 2 · h for pure PAN/PLA, thanks to increased water absorption (the contact angle decreases from 66.75° to 18°), increased porosity (from 69% to 93%), and higher tensile strength (from 7.8 to 13.9 MPa), thus improving the membrane's mechanical properties. Under a feed oil concentration of 50 ppm and a pressure of 2 bar, the modified membrane achieves an oil rejection rate of 94.6%, which rises to 100% at 550 ppm, indicating robust performance at higher contaminant levels. The flow recovery rate (FRR) is 98.8%, demonstrating excellent fouling resistance, further enhanced by the low surface roughness. After four cycles of operation and cleaning, the oil discharge remains stable with only a slight decrease in flow. The residual oil in the permeable material remains at 5 ppm, compliant with the WHO environmental discharge standards. Overall, PAN/PLA/PPW membranes offer high separation efficiency, operational stability, strong fouling resistance, durability, and environmental sustainability, making them a promising and effective filter for industrial oily wastewater treatment applications.