Fouling mitigation has always been an important concern in membrane
technology applications. One of the approaches used to improve performance
and reduce the impact of fouling is the development of new membrane materials.
With this objective, the authors have developed a number
of different novel surface modified polyethersulfone (PES) ultrafiltration (UF)
membranes via the addition of different hydrophiLic Surface Modifying
Macromolecules (LSMMs). The objective of this study was to compare performance
of the best experimental membrane (PES-LSMM) with nine commercial UF
membranes manufactured using five different types of base polymers
(polyethersulfone, polysulfone, cellulose acetate, polyacrylonitrile and cellulose).
All membranes were characterized by using atomic force microscopy, contact
angle measurement, solute transport analysis, charge measurement and then
evaluated through fouling tests with Ottawa River water (ORW).
Based on the small contact angles, high pore density, small pores and smooth
surfaces, the modified cellulose acetate (CQ40) and polyethersulfone (PU40)
membranes appeared to be the most promising in terms of fluxes. The PESLSMM
experimental membrane however had the lowest long-term flux reduction
(48%), comparable long term fluxes and the highest dissolved organic carbon
(DOC) rejection (80%). For the commercial membranes, the range of flux
reductions and DOC rejections were 52-61% and 66-79%, respectively. The high
initial DOC removal (72%) of LSMM membranes makes it a promising material
for hollow fiber membranes due to the frequent backwashing in this type of
membrane module. Given a thorough study of membrane surface characteristics
(porosity, hydrophilicity, charge and roughness), it was found that size exclusion
was not a significant factor on natural organic matter (NOM) rejection. Electrostatic repulsion and
morphology (surface roughness) had slight impacts on fluxes (J/Jo). The effect
on membrane performance was greater for surface charge. Includes 22 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 50 |
| Published : | 06/01/2007 |
