Membrane bioreactor (MBR) is the combination of a membrane filtration process with a suspended growth bioreactor. It is a very advanced technology and is now widely used
for municipal and industrial wastewater treatment.
2. MBR is the combination of a membrane process like
microfiltration
or ultra filtration with a suspended growth bioreactor, and
is now widely used for municipal and
industrial wastewater treatment with plant sizes up to
90,000 population equivalent.
MBR(Membrane Bio Reactor) is an Advanced technology is now
widely used for municipal and industrial wastewater treatment
plant. Most important aspect of MBR technology is production
of very high quality Treated Water consistently.
3.
4. Process of MBR:
When used with domestic wastewater, MBR processes can
produce effluent of high quality enough to be discharged
to coastal, surface or brackish waterways or to be
reclaimed for urban irrigation. Other advantages of MBRs
over conventional processes include small footprint, easy
retrofit and upgrade of old wastewater treatment plants.
5.
6. Two MBR configurations exist: internal/submerged, where
the membranes are immersed in and integral to the
biological reactor; and external/ sidestream, where
membranes are a separate unit process requiring an
intermediate pumping step.
Internal/submerged :
The filtration element is installed in either the main bioreactor vessel or
in a separate tank. The membranes can be flat sheet or tubular or
combination of both, and can incorporate an online backwash system
which reduces membrane surface fouling by pumping membrane
permeate back through the membrane.
External/side stream :
The filtration elements are installed externally to the reactor, often in a
plant room. The biomass is either pumped directly through a number
of membrane modules in series and back to the bioreactor, or the
biomass is pumped to a bank of modules, from which a second pump
circulates the biomass through the modules in series. Cleaning and
soaking of the membranes can be undertaken in place with use of an
installed cleaning tank, pump and pipe work.
8. Sequential batch reactors (SBR) are a
type of activated sludge process for
the treatment of wastewater. SBR reactors
treat wastewater such as sewage or
output from anaerobic
digesters or mechanical biological
treatment facilities in batches. Oxygen is
bubbled through the mixture of wastewater
and activated sludge to reduce the organic
matter (measured as biochemical oxygen
9. There are five stages in the treatment
process:
Fill
React
Settle
Decant
Idle
The inlet valve opens and the tank is being
filled in, while mixing is provided by
mechanical means (no air). This stage isDuring the fourth stage the outlet valve opens and the
clean supernatant liquor exits the tank.
10.
11. The various stages in the sequence are as
follows:
Stage 1: Filling
During this stage the SBR Tank is filled with the influent
wastewater. In order to maintain suitable F/M (food to
microorganism) ratios, the wastewater should be
admitted into the tank in a rapid, controlled manner. This
method functions similarly to a selector, which
encourages the growth of certain microorganisms with
better settling characteristics.
Stage 2: Reaction
This stage involves the utilization of biochemical oxygen
demand (BOD) and ammonia nitrogen, where
12. Stage 3: Settling
During this stage, aeration is stopped and the sludge
settles leaving clear, treated effluent above the sludge
blanket. Duration for settling varies from 45 to 60
minutes depending on the number of cycles per day.
Stage 4: Decanting
At this stage of the process effluent is removed from the
tank through the decanter, without disturbing the settled
sludge.
Stage 5: Idling
The SBR Tank waits idle until it is time to commence a
new cycle with the filling stage.
Stage 6: Sludge Wasting Excess activated sludge is
wasted periodically during the SBR operation. As with
any activated sludge treatment process, sludge wasting
is the main control of the effluent quality and
