Removal of Ampicillin and Humic Acid Using a Novel Synthetic Polyvinyl Chloride Ultrafiltration Membrane Modified by Magnetic Graphene Oxide/Metformin Hybrid Nanoparticles

In this research, Metformin/GO/Fe3O4 (MMGO) and GO/Fe3O4 (MGO) nanoparticles were synthesized and incorporated into PVC to fabricate novel MMGO/PVC and MGO/PVC nanocomposite membranes via casting for the removal of ampicillin (AMP) and humic acid (HA) from wastewater at 10 and 20 ppm. The synthesized membranes were characterized using FTIR, SEM, AFM, XRD, and contact angle analysis. Results showed that membranes modified with 0.5 wt % nanoparticles performed significantly better. The pure water flux increased from 223.44 kg/m2·h (bare PVC) to 467.58 kg/m2·h (MMGO/PVC). Rejection rates improved from 81.80% to 96.61% for HA and from 61.92% to 88.35% for AMP. The flux recovery ratio (FRR) increased from 72.74% to 96.20%. In long-term filtration, the flux of the pristine membrane declined by 39.8% after four cycles, while the MMGO/PVC membrane showed only a 5.7% reduction, demonstrating superior antifouling and stability for water treatment.