عنوان مقاله [English]
In the present study, a mixed matrix nanofiltration membrane was prepared by blending magnetic Fe3O4 and amino-functionalized Fe3O4 (Fe3O4-APTES) nanoparticles into polyethersulfone (PES) matrix. To achieve this purpose, Fe3O4 and Fe3O4-APTES 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 and Fe3O4-APTES nanoparticles on membrane morphology and hydrophilicity. The effect of Fe3O4 and Fe3O4-APTES 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 and Fe3O4-APTES 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 and Fe3O4-APTES content, showed the effect of hydrophilic nanoparticles on membrane surface hydrophilicity. Membrane porosity was increased from 63.3% for the bare PES to 73.3% and 78.0% for the Fe3O4-0.50 and Fe3O4-APTES respectively, due to the presence of nanoparticles. Pure water flux was increased from 36.1 to 80.4 (L/m2 h) by increasing the Fe3O4 nanoparticle content from 0.00 to 0.50 wt.% and then increased to 92.9 (L/m2 h) by addition of the Fe3O4-APTES nanoparticle. 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 Fe3O4-APTES 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 Fe3O4-0.50 were 31.9, 12.8, and 19.1% respectively, and 26.8, 10.3, and 16.5% for the Fe3O4-APTES, showed higher fouling resistance of the Fe3O4 and Fe3O4-APTES 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 and 83.5% for the Fe3O4-0.50 and Fe3O4-APTES, respectively. Dye rejection performance for all prepared membranes was near total removal (more than 95%). The maximum and the minimum removal efficiency were observed for Fe3O4-APTES (99.5%) and bare PES (95.4%), respectively. the results introduced Fe3O4 and Fe3O4-APTES nanoparticles as an excellent membrane modifier for wastewater treatment objectives.