عنوان مقاله [English]
In the present study, a mixed matrix nanofiltration membrane was prepared by blending magnetic Fe3O4 nanoparticles into polyethersulfone (PES) matrix. To achieve this purpose, different dosages (0.25wt%, 0.50wt%, and 1.00wt%) of magnetic Fe3O4 nanoparticles were introduced into PES matrix using phase inversion technique. Scanning electron microscopy (SEM), water contact angle and overall porosity technique were used to investigate the effect of Fe3O4 nanoparticles on membrane morphology and hydrophilicity. The effect of Fe3O4 nanoparticles on membrane performance was studied in terms of pure water flux, antifouling properties. Nanofiltration performance of the membranes was examined using reactive green 19 (RG19) separation. The Fe3O4 modified membranes showed an increased hydrophilicity, porosity, permeability, and dye rejection efficiency and also improved antifouling properties, compared to the bare PES. Water contact angle result demonstrated a decreasing trend with addition of Fe3O4 content, showed the effect of hydrophilic Fe3O4 nanoparticles on membrane surface hydrophilicity. Membrane porosity was increased from 63.3% for the bare PES to 73.3% for the PES-Fe3O4-0.50wt% due to the presence of nanoparticles. Pure water flux was increased from 36.1 to 80.4 (L/M2 h) by increasing the nanoparticle content from 0.00 to 0.50 wt.% and then decreased to 65.9 (L/M2 h) by increasing the nanoparticle content to the 1.00wt%. So that when the content of CDs was 0.50 wt.%, the pure water flux was more than twice of bare PES permeability. Fouling resistance of the prepared membranes was investigated with filtration of a 250 mg/L bovine serum albumin (BSA) solution. All modified membranes showed improved antifouling properties compared to the bare PES. The best antifouling properties were observed for the PES-Fe3O4-0.50wt% membrane. The values of total, reversible and irreversible fouling for the bare PES were 54.0, 12.6, and 41.4% respectively. Whereas these values for the PES-Fe3O4-0.50wt% were 31.9, 12.8, and 19.1% respectively, showed higher fouling resistance of the Fe3O4 modified membranes due to the more hydrophilic surface. Flux recovery ratio (FRR) was measured as the most important fouling factor. The value of FRR was increased from 58.6% for the bare PES to 80.9% for the PES-Fe3O4-0.50wt%. Dye rejection performance for all prepared membranes was near total removal (more than 95%). The maximum and the minimum removal efficiency were observed for PES-Fe3O4-0.50wt% (98.4%) and bare PES (95.4%), respectively. the results introduced Fe3O4 nanoparticles as an excellent membrane modifier for wastewater treatment objectives.