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To unravel fouling and defouling mechanisms of protein, saccharides and natural organic matters (NOM) on polymeric membrane during filtration, this study investigated filtration characteristics on polyvinyl chloride (PVC) ultrafiltration membranes with bovine serum albumin, dextran, humic acid as model foulants. Membrane fouling and defouling performances were analyzed through monitoring the flux decline during filtration and flux recovery during physical backwash. Physico-chemical properties (e.g., hydrophobicity and surface charge) of PVC membrane and foulants were characterized, which were used in the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory to calculate the interaction energies between membrane foulant and foulant-foulant. The results showed that at the later filtration stages the fouling rate was strongly correlated with the deposition rate, which was determined by the interaction energy profile calculated by EDLVO. Moreover, the adhesion forces of membrane–foulant and foulant–foulant were further measured by atomic force microscopy (AFM) with modified colloidal probes. A positive correlation (R2 =0.845) between particle detachment rate (determined by adhesion force) and defouling rate was developed for BSA and HA foulants that led to cake layer formation. By contrast, dextran defouling rate was off this correlation as dextran partially clogged membrane pores due to its smaller size.
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This content will become publicly available on February 1, 2026
Pattern size relative to oil droplet size effect on oil fouling in nanofiltration
Membrane fouling is a major issue in many membrane applications. There are numerous methods used in attempt to mitigate membrane fouling, with one method being membrane surface patterning. However, it is still unclear how the ratio of foulant size to pattern size affects membrane fouling. In this study, we investigated constant foulant size while varying the pattern size on the membrane surface to be smaller than (300-nm), equal to (10-μm), and larger than (50-μm) the foulant (10-μm) on polyamide nanofiltration membranes. These membranes were compared to a commercial nanofiltration membrane and a control flat synthesized membrane. The membranes were tested with water, 2000 ppm Na2SO4, and three cycles of a n-dodecane (as oil) brine solution in a dead-end cell to assess the fouling resistance and flux recovery ability of each polyamide membrane type. From the fouling experiments, it was determined that none of the pattern sizes significantly affect the flux recovery ratio, but smaller than and larger than patterns decreased the fouling rate on the polyamide membranes by a small margin.
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- Award ID(s):
- 1941700
- PAR ID:
- 10553229
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Journal of Membrane Science
- Volume:
- 715
- Issue:
- C
- ISSN:
- 0376-7388
- Page Range / eLocation ID:
- 123457
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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