Enhanced nutrient and organic pollutant removal from palm oil mill effluent (POME) using nano-hybrid PVDF-PVP-SiO₂ membranes: Mechanistic and long-term performance evaluation

• 1.0g SiO₂ loading optimizes membrane hydrophilicity and porosity. • >93% removal of TN, TP, COD, BOD₅, TSS from raw POME achieved. • Flux recovery >91% and low irreversible fouling (<8%) over 3 cycles. • Homogeneous SiO₂ dispersion confirmed by SEM, FTIR, EDX, zeta potential. • Modified membrane delivered 29.58 L/m²·h flux compared with 8.07 L/m²·h unmodified This research investigates the long-term performance of a SiO₂-modified PVDF-PVP Ultrafiltration Membrane for the removal of nutrients and organic pollutants from Palm Oil Mill Effluent. Membrane-based treatment of palm oil mill effluent (POME) is limited by rapid fouling and inconsistent multi-pollutant removal over extended operation. This study addresses the gap in understanding the mechanistic stability of nutrient removal across repeated filtration cycles using nano-enhanced membranes. SiO₂-modified polyvinylidene fluoride–polyvinylpyrrolidone (PVDF-PVP) ultrafiltration membranes were fabricated with SiO₂ loadings ranging from 0 to 1.5 g and evaluated over three consecutive 10-hour filtration cycles each using raw POME. The optimized membrane (1.0 g SiO₂) was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, porosity analysis, and zeta potential measurements. The 1.0 g SiO₂ membrane exhibited enhanced hydrophilicity (contact angle 56.9°), increased porosity (49.99%), and a highly negative surface charge (−59.64 mV at pH of 9.5). In Cycle 1, it achieved removal efficiencies of 96.29 ± 0.29% for total nitrogen (TN), 96.20 ± 0.49% for total phosphorus (TP), 95.76 ± 0.17% for chemical oxygen demand (COD), and 93.64 ± 0.21% for total suspended solids (TSS). Performance remained high in subsequent cycles (70–85% removal), with significantly lower irreversible fouling (5.32%) and higher flux recovery (94.68%) than in the neat membrane (73.18% irreversible fouling). The modified membrane also sustained a higher steady-state permeate flux (29.58 L/m²·h) at a lower transmembrane pressure (∼18 kPa). The SiO₂-PVDF-PVP nano-hybrid membrane demonstrates exceptional antifouling properties, durable multi-pollutant removal, and operational stability, proving its potential as an effective and scalable solution for long-term industrial POME treatment.