MBR is a brand-new waste water treatment process by combining the traditional biochemical processes and membrane separation processes. It is not the simple overlay, but also an organic integration, as shown in the following figure.
MBR is high efficient combining of membrane separation technology and biological treatment, it originates from replacement of secondary sedimentation pool in activated sludge process with membrane separation to separate solids and liquids. The principle is still use the microbes deterioration function to remove organic pollutants, but because membrane’s excellent rejection performance, activated sludge (MLSS) is fully captured in the reactor, which has greatly strengthened deterioration function. Membrane permeate water is conveyed by low-pressure suction pump. This process not only effectively meets the purpose of separating sludge and water, but also have the advantages that sewage level 3 treatment traditional process does not have :
Good permeate water quality, high stability, much higher microbes density than activated sludge process, which has greatly enhanced the biodegradable and anti-load impacts capacity. In addition, sludge retention duration is long, so that slowly reproduced bacterias shall have time to breed in reactor, especially ideal for organic substance with less biodegradability and ammonia nitrogen removal. On the one hand, membrane separation rejects macromolecule substance which is smaller than membrane pores, this ensures stable output of water with good bacteria removal, eliminate suspended solids and reduce BOD performance;
Small footprint, membrane bio-reactor could maintain a relatively high level of the sludge concentration, usually activated sludge will be 8 – 12g/L, which is 2.5 – 5 times than a traditional biological treatment, and the system has eliminated secondary sedimentation pool and the sludge recirculation equipment, so that footprint can be saved;
Operating and maintenance simple, Membrane Separation Unit process is simple, its outflow water and operation was not affected by sludge expansion and other factors, operating and maintenance simple and easy, and easy-to-realize automatic control management.
The sludge processing cost is low and has high concentration, longer duration, this means that sludge discharge amount is low, which is only 20% of traditional process, and extremely beneficial for the follow-up sludge treatment .
SINOHYDRO Group Venezuela New Cabrera Power Plants total membrane water treatment projects
Suntar and SINOHYDRO Group cooperated in 2011, to utilize total membrane solution to process heavily polluted (high ammonia and nitrogen) lake water as fulfilled boiler feeding water. Pre-treatment utilizes biochemical+MBR process mode, in-depth processing utilizes ultra-filtration+reverse osmosis process mode.
Projects operation parameters as below:
|Daily processing capacity||4,800 m3|
|Outflow water conductivity||Less than 0.1 μS/cm|
|Water recovery rate||More than 58%|