Membrane technology has led to a revolutionary new concept in wastewater treatment. Membranes act as a barrier to bacteria and suspended solids to produce a low turbidity treatment plant effluent with very low bacteria counts.
MBR is the combination of a membrane process like microfiltration or ultra filtration with a suspended growth bioreactor. This very compact arrangement produces a MF/UF quality effluent suitable for reuse applications or as a high quality feed water source for Reverse Osmosis treatment
The submerged configuration relies on coarse bubble aeration to produce mixing and limit fouling. The energy demand of the submerged system can be up to 2 times lower than the side stream systems and submerged systems operate at a lower flux, demanding more membrane area. In submerged configurations, aeration is considered as one of the major parameter on process performances both hydraulic and biological. Aeration maintains solids in suspension, scours the membrane surface and provides oxygen to the biomass, leading to a better biodegradability and cell synthesis.
MBRs operate at solid retention times (SRT) as low as 10–20 days, resulting in more manageable mixed liquor suspended solids (MLSS) levels (10-15 g/L). Thanks to these new operating conditions, the oxygen transfer and the pumping cost in the MBR have decreased and overall maintenance has been simplified. Typical hydraulic retention times (HRT) range between 3 and 10 hours. In terms of membrane configurations, mainly hollow fibre and flat sheet membranes are applied for MBR applications.
+ Reduced plant footprint as Secondary clarifiers and tertiary filtration are eliminated
+ Footprint can be further reduced because other process units (digesters or UV disinfection and aeration basin volume) can also be eliminated/ minimized
+ Long sludge age, hence low sludge production
+ Produces a MF/UF quality effluent suitable for reuse applications
+ Can be housed in a building
+ Reduced sludge dewatering cost
+ Municipal wastewater for high quality outlet water
+ For re-cycling systems
+ Wastewater from numerous industrial sources such as paper mills, beverage ingredient processors, slaughterhouses, food processors, chemical plants, tank truck cleaning operations, etc.