IEC 128 |
| Jian-Jun Qin, Maung-Htun Oo, and Hsiaowan Lee. Centre for Advanced Water Technology, Singapore Utilities International Pte Ltd, Blk 2, # 241, 18 Nanyang Drive, Singapore 637723, Singapore, Singapore |
| In the production of high quality drinking water from surface water, removal of natural organic matters (NOM) has recently emerged as a critical issue because it is found that NOM can result in the formation of disinfection by-products - trihalomethanes (THMs) which is harmful for human being and microbial regrowth in distribution systems, and impede the removal of iron and manganese from the water. In nanofiltration (NF) and reverse osmosis processes (RO), NOM can attach to the membrane surface and cause serious fouling. Therefore, the effective removal of NOM from water has become a challenging research and development area in current development of water purification technologies. However, there is no commercially available hollow fibre ultrafiltration membrane with low molecular weight cut-off (MWCO) (or small pore size), low fouling tendency and high permeation flux that is currently suitable for NOM removal. Although NF or RO in spiral-wound module can be used to remove NOM, the current commercial NF or RO membranes have a low water flux in a range of 3~7 E+5 L/h/m2/Pa. In this study, a high performance polyethersulfone (PES) hollow fiber ultrafiltration membrane has been prepared for removal of NOM. The membrane was spun from a dope solution containing PES / poly (vinyl pyrrolidone) / N-methyl-2-pyrrolidone (NMP) by using a wet-spinning process. Characterization of the membrane in terms of pure water flux, MWCO and retention for humic acid were conducted and the fouling resistance was analyzed. The experimental results showed that the membrane had a pure water flux of 20 E+5 L/h/m2/Pa and a nominal MWCO of around 6 000 Da for PEG. The results also showed that the retention for humic acid was over 97% and the membrane experienced very low fouling tendency for a solution containing humic acid. The SEM images revealed that the membrane had an outer dense skin and a porous inner surface. |
|
Nanotechnology and the Environment
5:00 PM-7:00 PM, Tuesday, March 25, 2003 Convention Center -- Hall G, Poster
Sci-Mix
Division of Industrial and Engineering Chemistry |