AWWA ACE65396

Fouling mitigation has always been an important concern in membranetechnology applications. One of the approaches used to improve performanceand reduce the impact of fouling is the development of new membrane materials.With this objective, the authors have developed a numberof different novel surface modified polyethersulfone (PES) ultrafiltration (UF)membranes via the addition of different hydrophiLic Surface ModifyingMacromolecules (LSMMs). The objective of this study was to compare performanceof the best experimental membrane (PES-LSMM) with nine commercial UFmembranes manufactured using five different types of base polymers(polyethersulfone, polysulfone, cellulose acetate, polyacrylonitrile and cellulose).All membranes were characterized by using atomic force microscopy, contactangle measurement, solute transport analysis, charge measurement and thenevaluated through fouling tests with Ottawa River water (ORW).Based on the small contact angles, high pore density, small pores and smoothsurfaces, the modified cellulose acetate (CQ40) and polyethersulfone (PU40)membranes appeared to be the most promising in terms of fluxes. The PESLSMMexperimental 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 fluxreductions and DOC rejections were 52-61% and 66-79%, respectively. The highinitial DOC removal (72%) of LSMM membranes makes it a promising materialfor hollow fiber membranes due to the frequent backwashing in this type ofmembrane module. Given a thorough study of membrane surface characteristics(porosity, hydrophilicity, charge and roughness), it was found that size exclusionwas not a significant factor on natural organic matter (NOM) rejection. Electrostatic repulsion andmorphology (surface roughness) had slight impacts on fluxes (J/Jo). The effecton membrane performance was greater for surface charge. Includes 22 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2007

Number of Pages:

50

File Size:

1 file , 1.1 MB