Công nghệ MBBRSeminar libre

Moving Bed Biofilm
Reactor
For Sewage Treatment

Guided by:
Dr. A. A. Kazmi
Assistant Professor
Department of Civil Engineering
IIT Roorkee


Background
• One of the major researches going on nowadays is the
urban and industrial wastewater reclamation. The
wastewater being discharged into the environment in an
untreated or insufficiently treated way is causing severe
problems including the eutrophication.

• As compared to the other processes, Biological
Processes (biofilms) are proving to be the satisfactory
solution for the removal of organic compounds and
nutrients from the wastewater for discharging into
environment.


Different Processes
Attached
Growth
Static Fixed
Film

Suspended
Growth

Dynamic
Fixed Film

Activated
Sludge

Trickling
filters

RBC

Continuous
Treatment

Rope Media

MBBR

Conventional
AS

SBR

Biological
Active Filters

Plastic

Seaweed Type

MLE

MBR

MBR

Batch
Treatment


About MBBR
• MBBR meaning Moving Bed Biofilm Reactor combines the

benefits of both activated sludge process and the fixed film
process.

• It is a continuous flow process which uses media/carriers which

provide sites for the attachment of active bacteria in a suspended
medium which can be used for wastewater treatment.

• The result is more treatment capacity within a given reactor

volume, resulting in a smaller footprint compared to a
conventional activated sludge process.


Arrangement of a MBBR

(Source: />

Principle behind MBBR
• The MBBR process uses carrier elements (plastic

carriers, PVA Gel beads) to provide sites for bacteria
attachment in a suspended growth medium.
• The carrier elements allow a higher biomass
concentration to be maintained in the reactor compared
to a suspended growth process, such as activated sludge.
• The biomass grows on small carrier elements that move
along with the water in the reactor.
• The movement is caused by aeration in the aerobic
version of the reactor and by a mechanical stirrer in the
anoxic/anaerobic version.


Principle behind MBBR

(Source : Rusten et al., 2006)


Flowsheet of MBBR

(Source : Wang et. al., 2006)


Media Used in MBBR
• The media includes the small carrier elements which allow

sites to retain active biomass within the bioreactor, thus
eliminating the need to control mixed liquor suspended solids
(MLSS) by recycling active sludge from secondary settlement
tanks.

• Carriers can differ from each other in material composition,
shape, specific surface area and treatment capabilities.

• Different kinds of media being used in MBBR and their
characteristics are given in the next slides.


(Source : Shrestha, 2013 )


Specific Surface area
(m2/g)
2.54×10-3
1.22×10-3
1.94×10-3
0.91

Media

Shape

Size

PB

PG
PS
S

Beads
Granules
Sheet
Cubic

K1

Cylindrical

0.9 mm dia
3 mm dia
11 cm dia
15×15×15 mm
10 mm dia
Length 7mm

K3

Cylindrical

10 mm dia
Length 7 mm

0.5×10-3

PVA-gel beads

Spherical

4 mm dia

-

BioPortzTM

Cylindrical

20 mm dia
Length 20 mm

0.58×10-3

Poly propylene

Cylindrical

granules

0.35×10-3

Polyethylene Ball

Circular

10 mm dia
Length 7 mm

0.32×10-3

PVC plastic
tubes

Cylindrical

20.5 mm dia
Length 18.2 mm

0.15×10-3

HDPE grains
LDPE grains
Polypropylene grains
Polyurethane cubes

Granules
Granules
Granules
Cubes

3.0 mm
4.5 mm
3.5 mm
25×25×25 mm

1.177×10-3
0.755×10-3

1.001×10-3
1.102×10-3

(Source : Shrestha, 2013 )

5.0×10-3


Applications of MBBR
• The moving bed biofilm reactor process has been
used for many different applications.

• It was developed at the time when nitrogen removal
came into focus and most of the scientific data has
been gathered from this application.

• Later, however, organic matter removal has been
investigated further, including high-rate pretreatment for upgrading of activated sludge plants.


BOD/COD removal
• The MBBR process is ideally suited for carbonaceous
biochemical oxygen demand and chemical oxygen
demand
(BOD/COD)
removal
applications.
MBBR processes retain a large volume of biofilm
within the biological wastewater treatment process. As a
result, degradation of biodegradable contaminants are

sustained in highly compact tank sizes. Without the
requirement to return sludge, the process provides
increased protection against toxic shock, while
automatically adjusting to load fluctuations.


BOD/COD removal

(Source: Ødegaard, 2006)


Nitrification
• The moving bed biofilm reactor process has been used
for nitrification purposes in various process schemes
(Fig. (d)–(f)). Traditionally, nitrification is obtained by
adding reactor volume to reactors that have already
removed most of the organic matter (Fig. (d)). In
contrast to an activated sludge system, the heterotrophs
will dominate in the start of the process (first reactor)
and the nitrifiers in the end of the process (last reactor).
This makes it possible to optimise each of the processes
independent of the other.


Nitrification

(Source: Ødegaard, 2006)


Factors affecting Nitrification

(Source: Ødegaard, 2006)


Nitrogen Removal
• Nitrogen removal in MBBR plants may be
achieved by several process combinations, for
instance pre-denitrification (Fig. (g)), postdenitrification (Fig. (h)) or a combination of the
two – combined denitrification process (Fig. (i)).
The MBBR process may also be used in activated
sludge plants as a post-denitrification process (Fig.
(j)) or as hybrid activated sludge/biofilm process.


(Source: Ødegaard, 2006)


Literature Review
• Different studies have been conducted for studying
the different parameters which affect the effluent
quality of MBBR including:
• Different carrier elements
• Different HRT
• Different D. O. Levels


Wang et. al., 2006
• Wang et al., 2006 carried out a laboratory scale test
using biofilm carriers and a filling ratio of 50%.
The coagulant used was Fe(II) Sulphate

Heptahydrate solution. The performance of MBBR
was studied at the DO level of 2 mg/L and HRT of
6 hours. The phosphorous removal efficiency was
found to be greater than 75%. The highest removal
efficiency was observed to be ~92%.


Wang et. al., 2006
• In the study by Wang et al., 2006, it was shown
from the results of the average concentration of
NH4+, NO3- and NO2- and their removal efficiencies
that the efficiency of nitrification reached >90%
when the D.O. was kept greater than 2 mg/L. It was
further stated that the average TN removal
efficiency of 89.9% from domestic wastewater
could be attained at DO of 2 mg/l. It has been
considered that DO diffusion through the biofilm
be the rate determining step for media nitrification.


Chu & Wang, 2011
• In a study by Chu & Wang, (2011), a moving bed
biofilm
bioreactor
was
designed
with
biodegradable polymers PCL (Polycaprolactone)
serving as biofilm carriers. It was seen that more
than 86% of TOC removal efficiency was achieved.

The average TN removal efficiency of 74.6% was
achieved. TOC in the effluent was lower than
2.3mgL-1.


Chu et. al., 2011
• Chu et al., (2011) investigated the performance of MBBR for

the removal of organics and nitrogen from wastewater with a
low C/N ratio using the two different materials as carrier for
their research, namely PUF and biodegradable polymer PCL
particles.
• This study demonstrated the MBBR with PUF had good results in

the TOC and ammonium removal, 90% and 65%, compared with
72% and 56% for reactor filled with PCL carriers at an average
HRT of 14 h.

• The MBBR with biodegradable PCL carrier showed good
performance in terms of TN removal.


(Source: Chu et. al., 2006)