Overview of the Technology
The MBR process involves a suspended growth activated sludge system that utilizes micro-porous membranes
for solid/liquid separation in lieu of secondary clarifiers. 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.
Indicative output quality of MF/UF systems include SS < 1mg/L, turbidity < 0.2 NTU and
up to 4 log removal of virus (depending on the membrane nominal pore size). In addition,
it provides a barrier to certain chlorine resistant pathogens such as Cryptosporidium and Giardia.
The Membrane Bioreactor (MBR) process is an emerging advanced wastewater treatment technology
that has been successfully applied at an ever increasing number of locations around the world.
In addition to their steady increase in number, MBR installations are also increasing in terms of scale.
A number of plants with a treatment capacity of around 5 to 10 ML/d have been in operation for several years now whilst the next generation
(presently undergoing commissioning or under contract) have design capacities up to 45 ML/d.
The typical arrangement includes submerged membranes in the aerated portion of the bioreactor,
an anoxic zone and internal mixed liquor recycle (e.g Modified Lutzack-Ettinger configuration).
Incorporation of anaerobic zones for biological phosphorus removal has been the focus of recent research.