Abstract
This study compares fouling propensities of reverse osmosis (RO) membranes in two parallel MBR-RO systems. Two MBRs were operated at different food to microorganism (F/M) ratios and the permeate was fed to the respective RO membrane. The results show that greater amounts of organic substances in the high F/M (0.50g/gday-1)-MBR permeate led to higher RO fouling rates (>4.5-fold) compared to the low F/M ratio (0.17g/gday-1)-MBR permeate. The presence of filters (~5μm) in the RO feed line and recycled RO concentrate line significantly alleviated RO fouling. Chemical analysis of RO foulants indicated that the soluble polysaccharides and transparent exopolymer particles (TEP) accumulated on the RO membranes were strongly associated with RO fouling. However, propagation of bacterial cells on the membranes did not determine RO fouling development. This finding was further confirmed by confocal laser scanning microscopy images. Furthermore, excitation-emission matrix (EEM) fluorescence spectroscopy was used to trace the fate and transport of the potential soluble foulants in the MBR-RO system.
| Original language | English |
|---|---|
| Pages (from-to) | 37-45 |
| Number of pages | 9 |
| Journal | Desalination |
| Volume | 311 |
| DOIs | |
| Publication status | Published - 5 Feb 2013 |
Bibliographical note
Funding Information:The authors are grateful to Xi Chen and Stanislaus Raditya Suwarno for their technical assistance on CLSM analyses. This project was funded by the Economic Development Board (EDB) of Singapore in cooperation with Toray Industries, Inc. The EDB is also acknowledged for funding the Singapore Membrane Technology Centre (SMTC), Nanyang Technological University.
Other keywords
- Adenosine triphosphate
- Extracellular polymeric substances
- Soluble polysaccharides
- Transmembrane pressure
- Transparent exopolymer particles