1. Introduction and
process description of
FAB/MBBR
By
KETAN WADODKAR
124180004
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2. Content
 MBBR (Moving Bed Biofilm
Reactor)
 Introduction
 Process Description
 Design Consideration
 Advantages
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3. MBBR (Moving bed biofilm
reactor)
 Small cylindrical shaped polyethylene carrier
added in aerated or non aerated basin to
support biofilm growth.
 Biomass grows primarily on protected surface on
the inside of the carriers.
 Air agitation or mixers are used to continuously
circulate carriers.
 Perforated plates at the outlet of the tanks keeps
biofilm carrier inside the tank.
 MBBR can be a single reactor or configured as
several reactors-in-series.
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Fig: Moving Bed Biofilm Reactor (MBBR)

5. FAB Reactor / MBBR
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FAB REACTOR
RAW SEWAGE
AIR DISTRIBUTION GRID
AIR INLET PIPING
SPECIALLY DEVELOPED
CARRIER ELEMENTS
EFFLUENT OUTLET
SYSTEM
TREATED
SEWAGE
V V V V V

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8.  Retention of the carrier within
the reactor encourages
selection and enrichment for
organisms that are best
adapted to the nutrient
conditions that prevail in that
reactor at steady state.
 Carriers occupy 25-70% of
tank volume.
 The specific surface area of
carrier is about 500m2
/m3
.
 The carriers are slightly
buoyant and have a specific
gravity between 0.94 and 0.96
g/cm3
.
 Media carrier life is around 15-
20 years.
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9. Various types of bio carriers
used
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10.  treatment capacity is a function of the specific surface
area (SSA) of the reactor.
 The SSA for a reactor = the quotient of the total surface
area on the carrier that is available for biofilm
establishment and the reactor volume.
TABLE: SSA of attached growth media (Source: Metcalf
&eddy, 2003)
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11. Design Consideration
 Adequate preliminary treatment:
 to prevent plastic biofilm carrier retention screen blinding
 To prevent the accumulation of inert material in MBBR
tank
 Well designed aeration system:
 Promote the rolling water circulation pattern that
uniformly distributes plastic biofilm carriers throughout the
MBBR.
 diffused aeration is used for aerobic MBBR tank (Course
bubble diffusion)
 Typical oxygen transfer rates are 2.5 – 3.5 % per meter of
water submergence.
 Typical air flow rate = 6 to 8 m3
/m2
.h.
 Properly specified/designed mechanical mixers for
denitrification tank 16/06/13
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12. Fig: Influence of organic load and reactor DO concentration on
TAN removal in a Kaldnes MBBR, at 15 C and with TAN in excess (2.5
mg N/L). (Hem et al. 1994). 16/06/13
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13.  Media carrier retention screens:
 Scum must be removed from the system
 Typical screen design allows for a maximum 50 to
150mm head loss
 Effective liquid–solid separation system:
 The general SS in MBBR effluent found out to be 150-250
mg/L, when treating medium to high strength
wastewaters.
 MBBR are low HRT biofilm reactors
 According to Ahl et al. (2006), the particle size
distribution shifts towards larger particle size with
increase in HRT.
 As biomass accumulation is settling independent, MBBR
is flexible in choice of settler used. (Coagulation &
flocculation. Tube settler, MF/UF etc.)
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14.  Length-to-width ratio (L:W) in the range 0.5:1 to 1.5:1.
 Ratio more than above results in non uniform
distribution of bio carriers.
 Biofilm thickness is controlled by air flow or
mechanical mixing energy.
 Low-rate MBBRs promote nitrification.
 Medium-rate MBBRs typically are designed for an
OLR in the range 5 to 10 g BOD5/m2
.d (at 10uC).
 Higher-rate systems require chemically enhanced
liquid–solids separation and/or flotation. OLR = 45-60
g BOD5/m2
d @25 o
C. (Ødegaard, 2006).
 MBBR support SNDN which is dependant on type of
carrier selected.
 It do no require any return activated sludge or
backwashing.
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15. Advantages:
 High-efficiency cBOD removal and nitrification
(even in low temperature environments)
 Retention of slow-growing and temperature-
sensitive bacterial populations (i.e., autotrophic
nitrifiers and methanol-degrading heterotrophs,
respectively)
 low HRT
 high biomass concentration
 low solids loading on liquid–solids separation unit
processes
 Reduced sludge production compared with
activated sludge
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16.  No problems with odours,
snails or red-worms as in air
phase fixed films.
 Non clogging design.
 Is a continuous system and
biofilm thickness is maintained
by the aeration-mixing
process.
 Smaller foot prints.
 MBBR Provides Five times the
Biofilm Surface Area in less
than ¼ Reactor Volume as
Trickling Filter
 Can be operated at varying
influent load
 Can be easily retrofitted.
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17. References
 McQuarrie J. P., Boltz J. P. (2011) Moving Bed Biofilm Reactor
Technology: Process Applications, Design, and Performance;
Water Environment Research, London, United Kingdom, 83 (6),
page no. 560-575.
 Ødegaard, H. (2006) Innovations in Wastewater Treatment: The
Moving Bed Biofilm Process. Water Sci. Technol., 53 (9), 7–33.
 Hem, L.J., Rusten, B., Ødegaard, H., 1994. Nitrification in a
moving bed biofilm reactor. Water Res. 28 (6), 1425–1433.
 www.Wikipedia.org
 www.anoxkaldnes.com
 www.headworksusa.com
 www.thermaxindia.com
 Metcalf and Eddy (2003), Wastewater Engineering: Treatment
and Reuse, 4th
Edition, TATA McGraw-Hill, New Delhi.
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