Ultrafiltration of aquatic humic substances through magnetically responsive polysulfone membranes

作者：Azmi Nur Atiah; Ng Qi Hwa; Low Siew Chun^*

来源：Journal of Applied Polymer Science, 2015, 132(21): 41874.

DOI：10.1002/app.41874

• hydrophilic polymers
• magnetism and magnetic properties
• membranes
• morphology
• nanoparticles
• nanowires and nanocrystals

Organic foulants, such as humic acid substances, contribute to the irreversible fouling and flux decline in membrane separation processes. To reduce the membrane fouling potential, in this study, we explored the end-capping of functionalized nanostructured magnetite (Fe3O4) with poly(acrylic acid) (PAA) on the surface of the polysulfone (PSF) membrane. The binding stability of PAA-functionalized Fe3O4 [functionalized magnetite-responsive nanoparticles (F-MNPs)], combined with field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometry, were studied to determine the deposited morphology and magnetic properties of F-MNPs on the membrane surface. In addition, the fouling analysis of the modified (F-MNPs-PSF) and unmodified (PSF) membranes were also being investigated through the filtration study. The results show that the magnetically responsive F-MNPs-PSF membrane developed in this study achieved high efficiency for the removal of humic substances when they were exposed to an oscillating external magnetic field. During filtration, the external magnetic field indirectly generated a torque that twisted the deposited Fe3O4 on the membrane surface. The actuated iron oxides consecutively reduced the concentration polarization around the top surface of the membrane and sequentially reduced the fouling propensity. These results provide some insight into the membrane's antifouling stability, which could be useful for environmental remediation.

• 出版日期2015-6-5