Abstract
Membrane bioreactors (MBRs) have been increasingly used for municipal wastewater treatment. Systems where the membranes are submerged in the bioreactor, and scoured by the aerating gas stream, are very common and the Kubota process is a classic example of this technol. Current treatment plants are designed to cope with 3 times the av. dry weather flow (DWF) of wastewater to accommodate variable flow rates, and hence are over-sized compared to av. or normal conditions. If throughput in submerged MBRs can be changed readily by manipulation of the aeration rate, due to increased scouring of the membrane and a corresponding increase in crit. flux, a smaller plant may be designed compared to the 3*DWF rule. High throughput operation may be achieved using a high aeration rate to generate a high crossflow velocity to minimize fouling, and at av. or low throughput a low aeration rate may be used to minimize energy consumption. The aim was to explore the feasibility of designing smaller membrane plants using the aeration rate to manipulate crit. flux in situ, and thereby allow variable throughput. It is concluded that (a) permeate flux and aeration rate are important hydrodynamic parameters that must be controlled to avoid excessive membrane fouling; (b) intermittent permeation is an effective membrane cleaning technique for long-term sustainability of flux; and (c) manipulation of the crit. flux through variation of aeration rate is possible in situ in submerged MBR systems. [on SciFinder (R)]
Original language | English |
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Pages (from-to) | 13-19 |
Number of pages | 7 |
Journal | Journal of Membrane Science |
Volume | 242 |
Issue number | 1-2 |
Early online date | 28 Jul 2004 |
DOIs | |
Publication status | Published - 15 Oct 2004 |
Keywords
- submerged membrane bioreactor aeration
- A4 membrane bioreactor
- in situ manipulation of crit. flux in submerged membrane bioreactors using variable aeration rates and effects of membrane history)
- Wastewater treatment (aerobic