Moving Bed Biofilm Bioreactor (MBBR) process uses the whole
tank volume for biomass growth. It uses simple floating media, which are
carriers for attached growth of biofilms. Biofilm carrier movement is caused by
the agitation of air bubbles. This compact treatment system is effective in
removal of BOD as well as nitrogen and phosphorus while facilitating effective
solids separation.
Design and Construction Principles
MBBR units are placed in series based on the load entering each
reactor. Neutralised and settled wastewater passes through MBBR for reduction
in BOD/COD. Most of the MBBR plants are provided with vertically or
horizontally mounted rectangular mesh sieves or cylindrical bar sieves. Biofilm
carriers are made up of high density (0.95 g/cm3) polyethelene.
These are normally shaped as small cylinders with a cross inside and fins
outside. The standard filling of carrier is below 70% with a maximum specific
area not more than 465 m2/m3. Generally, design load for
COD-BOD removal is 20 g COD / m2d. Smaller carriers need smaller
reactor volume at a given loading rate (as g/m2d) when the carrier
filling is same.
It is advisable to use MBBR in combination with a septic tank, DEWATS or a
pre-coagulation step as a pre-treatment unit, depending on the local conditions
and input characteristics. It is a very robust and compact alternative for
secondary treatment of municipal wastewater, having removal efficiency for BOD
90 – 95% (low rate) and that of 75 – 80% for high rate. Average nitrogen
removal is about 85%. There is no need for sludge recirculation. Phosphorus and
faecal coliform reduction is feasible with additional passive (non-mechanical)
or active (mechanical) system components.
A constantly operating MBBR does not require backwashing or return
sludge flows. It has minimal head-loss. Coarse-bubble aeration in the aeration
zone in the wastewater treatment tank provides ease of operation at low-cost.
Agitation continuously moves the carrier elements over the surface of the
screen thus preventing clogging. Maintenance of MBBR system includes screening,
influent equalisation, clarifier system, sludge handling and integrated control
system. There is no need to maintain f/M ratio as there is self-maintenance of
an optimum level of productive biofilm. Skilled labour is required for routine
monitoring and operations of pumps and blowers.
You always need expert advise to design a efficient and cost effective system.
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ITEMS OF ENVO COMPACT
MODULE
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Sr
No
|
Item
|
Specification
|
Qty
|
Cost
|
|
1
|
Raw
Sewage Pump
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Submersible,auto running,kirlosker
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1 No
|
|
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2
|
Compact
module consisting of following units,.
1.Aeration-I
with aeration grid
2.Aeration-II
with aeration grid
3.Tube
settler with baffle and weir
4.Treated
water tank
5.Sludge
holding tank with aeration
|
MS with support frame, inside FRP, outside painted
|
LOT
|
|
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3
|
Diffuser
in Aeration Tank-I & II
|
Dome
type,Make:ENVO
|
LOT
|
|
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4
|
Floating
Media in aeration tank-I & II
|
|
LOT
|
|
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5
|
Tube
Deck Media in Tube Settler
|
|
LOT
|
|
|
6
|
Air
Blower,
|
Twin lobe Rotary type, Make: SGN
|
1 No
|
|
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7
|
Filter
Feed Pump
|
Kirlosker
|
1 No
|
|
|
8
|
Pressure
sand filter
|
MS
module with media and frontal pipes and valves,Make:ENVO
|
1No
|
|
|
9
|
Activated
carbon filter
|
MS
module with media and frontal pipes and valves,Make::ENVO
|
1No
|
|
|
10
|
Electric
starters,wires
|
Panel,starter
and wires to pump and blowers
|
LOT
|
|
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11
|
Pipe
& Fittings, PVC
|
PVC pipe and fittings
|
LOT
|
|
|
12
|
Sludge
Pump
|
kirlosker pump
|
1 No
|
|
|
13
|
Filter
Press
|
PP plates with filter cloth, Make:Saraswati
|
1
No
|
|
|
14
|
Erection
commissioning of the system
|
LOT
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