Eng. & Tech. Journal, Vol.30 , No.
9, 2012
Wastewater Treatment in Baghdad City Using Moving Bed
Biofilm Reactor (MBBR) Technology
Mohammed A. Abdul-Majeed
Ministry of Science and Technology/ Baghdad
Email:ABUDALIAMA@yahoo.com
Hisham Hmeed Alwan
Ministry of Science and Technology/ Baghdad
Mohammed Inam Baki
Ministry of Science and Technology/ Baghdad
Fauad R- Abtan
Ministry of Science and Technology/ Baghdad
Hussein Irzooqi Sultan
Ministry of Science and Technology/ Baghdad
Received on: 11/7/2011 & Accepted on: 1/3/2012
ABSTRACT
In this study, a laboratory scale system of Moving Bed Biofilm Reactor
(MBBR) was used to treat municipal wastewater from a domestic community in
Baghdad City to get the water free from BOD for reuse in the irrigation or
discharge to the river. The aim of the described experimentation was the
comparison of a low cost MBBR and an activated sludge system (AS); the other
aim from this research is to derive successful MBBR wastewater reuse projects in
Iraq. Laboratory experiments were conducted in two parts, firstly at BOD5 load of
about (150-200) mg/l, filling ratio of plastic elements in the MBBR reactor was
40%. Aerobic reactor consumed most of the biodegradable organic matter. The
BOD5 removal efficiencies were 78 and 90% for MBBR & AS respectively.
Second part when BOD5 load about (900-1300) mg/l used (synthetic wastewater)،
filling ratio is 67%. The removal efficiencies of BOD reached 73 % for AS and
about 88% for MBBR.
Keywords: Bioreactor, biofilm carriers, moving Bed Biofilm Reactor, BOD
removal, municipal wastewater in Iraq.
ﻤﻌﺎﻟﺠﺔ ﻤﻴﺎﻩ ﺍﻟﺼﺭﻑ ﺍﻟﺼﺤﻲ ﻓﻲ ﻤﺩﻴﻨﺔ ﺒﻐﺩﺍﺩ ﺒﺎﺴﺘﺨﺩﺍﻡ ﺘﻘﻨﻴﺔ
ﻤﻔﺎﻋل ﺍﻟﻁﺒﻘﺔ ﺍﻟﺒﻴﻭﻟﻭﺠﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ
ﺍﻟﺨﻼﺼﺔ
ﻓﻲ ﻫﺫﻩ ﺍﻟﺩﺭﺍﺴﺔ ﺘﻡ ﺘﻬﻴﺌﺔ ﻤﻨﻅﻭﻤﺔ ﻤﺨﺘﺒﺭﻴﻪ ﻗﻴﺎﺴﻴﺔ ﻟﻐﺭﺽ ﻤﻌﺎﻟﺠﺔ ﻤﻴﺎﻩ ﺍﻟﺼﺭﻑ ﺍﻟﺼﺤﻲ
ﻤﺼﺩﺭﻫﺎ ﺃﺤﺩ ﺍﻟﻤﺠﻤﻌﺎﺕ ﺍﻟﺴﻜﻨﻴﺔ ﻓﻲ ﻤﺩﻴﻨﺔ ﺒﻐﺩﺍﺩ ﺒﺎﺴﺘﺨﺩﺍﻡ ﻤﻔﺎﻋل ﺍﻟﻁﺒﻘﺔ ﺍﻟﺤﻴﻭﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ ﺒﻬﺩﻑ
( ﻭﺍﻟﺫﻱ ﻴﻤﻜﻥBOD) ﺍﺴﺘﺭﺠﺎﻉ ﺠﺯﺀ ﻜﺒﻴﺭ ﻤﻥ ﺍﻟﻤﺎﺀ ﺍﻟﺨﺎﻟﻲ ﻤـﻥ ﺍﻻﺤﺘﻴﺎﺝ ﺍﻟﺤﻴﻭﻱ ﻟﻸﻭﻜﺴﺠﻴﻥ
ﺍﻟﻬﺩﻑ ﻤﻥ ﺍﻟﺘﺠﺎﺭﺏ ﺍﻟﻤﺒﻴﻨﺔ ﻓﻲ ﻫﺫﻩ.ﺍﺴﺘﺨﺩﺍﻤﻪ ﻓﻴﻤﺎ ﺒﻌﺩ ﻷﻏﺭﺍﺽ ﺍﻟﺴﻘﻲ ﺃﻭ ﺃﻋﺎﺩﺘﻪ ﺇﻟﻰ ﺍﻟﻨﻬﺭ
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Eng. & Tech. Journal, Vol. 30 ,No. 9,2012 Wastewater Treatment in Baghdad City Using
Moving Bed Biofilm Reactor (MBBR)
Technology
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ﺍﻟﺩﺭﺍﺴﺔ ﻫﻭﺃﺠﺭﺍﺀ ﻤﻘﺎﺭﻨﺔ ﻤﺎﺒﻴﻥ ﺘﻘﻨﻴﺘﻲ ﻤﻔﺎﻋل ﺍﻟﻁﺒﻘﺔ ﺍﻟﺤﻴﻭﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ ﺍﻟﺘﻲ ﺘﻤﺘﺎﺯ ﺒﻜﻠﻔﺔ ﻗﻠﻴﻠﺔ
ﻭﺍﻟﻬﺩﻑ ﺍﻷﺨﺭ ﻫﻭ ﺘﻁﻭﻴﺭ ﺨﺒﺭﺓ ﻋﻤﻠﻴﺔ ﻋﺭﺍﻗﻴﺔ ﻓﻲ ﻤﺸﺎﺭﻴﻊ،(ﻨﺸﻁﺔﻭﺍﻟﻁﺭﻴﻘﺔ ﺍﻟﺘﻘﻠﻴﺩﻴﺔ )ﺍﺍﻟﺤﻤﺄﻩ ﺍﻟﻤ
.ﺃﻋﺎﺩﺓ ﺃﺴﺘﺨﺩﺍﻡ ﻤﻴﺎﻩ ﺍﻟﺼﺭﻑ ﺍﻟﺼﺤﻲ ﺍﻟﺘﻲ ﺘﺴﺘﺨﺩﻡ ﻫﺫﻩ ﺍﻟﻁﺭﻴﻘﺔ
ﺍﻟﺠﺯﺀ ﺍﻷﻭل ﻋﻨﺩﻤﺎ ﻴﻜﻭﻥ ﺍﻟﺤﻤل ﻟﻸﻭﻜﺴﺠﻴﻥ ﺍﻟﺤﻴﻭﻯ،ﺍﻟﺘﺠﺎﺭﺏ ﺍﻟﻤﺨﺘﺒﺭﻴﺔ ﺃﺠﺭﻴﺕ ﻓﻲ ﺠﺯﺌﻴﻥ
ﻟﺘﺭ ﻭﺤﺠﻡ ﺍﻟﺤﺸﻭﺍﺕ ﺍﻟﺒﻼﺴﺘﻴﻜﻴﺔ ﻓﻲ ﻤﻨﻅﻭﻤﺔ ﺤﻭﺽ ﺍﻟﻁﺒﻘﺔ/ ( ﻤﻠﻐﻡ200 -150) ﺍﻟﻤﻤﺘﺹ ﺒﺤﺩﻭﺩ
ﺍﻟﻤﻔﺎﻋل ﺍﻟﻬﻭﺍﺌﻲ ﺃﺴﺘﻬﻠﻙ ﺃﻏﻠﺏ ﺍﻟﻤﻭﺍﺩ. ﻤﻥ ﺤﺠﻡ ﺤﻭﺽ ﺍﻟﺘﻬﻭﻴﺔ%40 ﺍﻟﺒﻴﻭﻟﻭﺠﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ ﺒﺤﺩﻭﺩ
%90 ﻭ78 ﺍﻟﻌﻀﻭﻴﺔ ﺍﻟﻘﺎﺒﻠﺔ ﻟﻠﺘﺤﻠل ﺤﻴﺙ ﻜﺎﻨﺕ ﻜﻔﺎﺌﺔ ﺍﻷﺯﺍﻟﺔ ﻟﻸﻭﻜﺴﺠﻴﻥ ﺍﻟﺤﻴﻭﻱ ﺍﻟﻤﻤﺘﺹ ﺒﺤﺩﻭﺩ
ﻓﻲ ﺍﻟﺠﺯﺀ.ﻟﻜل ﻤﻥ ﺘﻘﻨﻴﺘﻲ ﺍﻟﺤﻤﺄﺓ ﺍﻟﻤﻨﺸﻁﺔ ﻭﺤﻭﺽ ﺍﻟﻁﺒﻘﺔ ﺍﻟﺒﻴﻭﻟﻭﺠﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ ﻋﻠﻰ ﺍﻟﺘﻭﺍﻟﻲ
ﻟﺘﺭ/ ( ﻤﻠﻐﻡ1300 -900) ﺍﻟﺜﺎﻨﻲ ﻟﻠﺘﺠﺎﺭﺏ ﻋﻨﺩ ﺍﻟﺤﻤل ﺍﻟﻌﺎﻟﻲ ﻟﻸﻭﻜﺴﺠﻴﻥ ﺍﻟﺤﻴﻭﻯ ﺍﻟﻤﻤﺘﺹ ﺒﺤﺩﻭﺩ
ﺒﻠﻐﺕ. ﻤﻥ ﺤﺠﻡ ﺤﻭﺽ ﺍﻟﺘﻬﻭﻴﺔ%67 ﺒﺎﺴﺘﺨﺩﺍﻡ )ﻤﻴﺎﻩ ﺼﻨﺎﻋﻴﺔ( ﻭﺤﺠﻡ ﺍﻟﺤﺸﻭﺍﺕ ﺍﻟﺒﻼﺴﺘﻴﻜﻴﺔ ﺒﺤﺩﻭﺩ
ﻟﺘﻘﻨﻴﺔ%88 ﻟﺘﻘﻨﻴﺔ ﺍﻟﺤﻤﺄﺓ ﺍﻟﻤﻨﺸﻁﺔ ﻭ%73 ﻜﻔﺎﺌﺔ ﺍﻷﺯﺍﻟﺔ ﻟﻸﻭﻜﺴﺠﻴﻥ ﺍﻟﺤﻴﻭﻱ ﺍﻟﻤﻤﺘﺹ ﺒﺤﺩﻭﺩ
.ﺤﻭﺽ ﺍﻟﻁﺒﻘﺔ ﺍﻟﺒﻴﻭﻟﻭﺠﻴﺔ ﺍﻟﻤﺘﺤﺭﻜﺔ
NTRODUCTION
B
iological treatment processes commonly relies on suspended biomass for
the removal of organic carbon and nutrients in municipal wastewater
plants. The conventional activated sludge (CAS) process is regarded as one
of the most effective and economical processes for the removal of organic
pollutants using suspended biomass [1]. The performance of the CAS process is
dependent on two sub-processes; conversion of colloidal and dissolved organic
matters into suspended biomass and physical separation of resulting biomass from
liquid by sedimentation.
There are many factors affecting the efficiency of (CAS) process such as sludge
retention time and organic loading [2, 3], and the aeration which facilitates the
production of biomass separated from liquid in clarifier [4]. But there are some
problems of sludge stability and the need of large reactors and settling tanks and
biomass recycling. At present, there has been growing interests in use of attached
growth systems (biofilm processes) which are related to biomass growth on support
media [5, 6]. The advantages of the attached growth systems over the (CAS) are
better oxygen transfer, higher nitrification rate, higher biomass concentrations,
more effective organic removal and relatively shorter hydraulic retention time
(HRT) [7,8]. Attached growth (biofilm) processes, however, have demonstrated
greater efficiency and sustainability than suspended growth processes, in the
presence of inhibitory compounds and at high or variable loadings [9]. For these
reasons, the moving bed biofilm reactor (MBBR) process was developed in
Norway in the late 1980s and early 1990s [10]. The Moving Bed Biofilm Reactor
is a highly effective biological treatment process that was developed on the basis of
conventional activated sludge process and biofilter process. Moving bed type
reactors are biofilm processes utilizing small plastic biomass carriers that mix in
the water. The Kaldnes patent's [10] polyethylene carrier elements are shaped like
small cylinders with a cross inside and longitudinal fins on the outside. The bulk
carrier volume relative to reactor volume is 40–70%. The carriers have a potential
growth area for a biofilm of about 500 m2 m-3 at 70% filling, while the efficient
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Eng. & Tech. Journal, Vol. 30 ,No. 9,2012 Wastewater Treatment in Baghdad City Using
Moving Bed Biofilm Reactor (MBBR)
Technology
.
growth area is calculated to be about 350m2 m-3 [11]. The use of biomass carriers is
becoming common world-wide, for many applications, some of which are:
compact low operation units, industrial wastewater roughing filters, retrofit and
upgrade of municipal wastewater.
Nitrification in Kaldnes MBBRs has been thoroughly studied using both
synthetic wastewater [12] and municipal wastewater [13]. As for all biofilm
reactors, nitrification rates are influenced by the organic load, the dissolved oxygen
(DO) concentration in the reactor, the total ammonium nitrogen (TAN)
concentration, the temperature, the pH and alkalinity. Item et al., [12] showed for a
situation with 15 ºC and excess TAN concentration at an organic load of
1gBOD5/m2 biofilm surface area/d, a TAN removal rate of 1 g NH4–N/ (m2.d) was
achieved at a DO concentration of about 5 mg/L. MBBR was studied as biological
treatment processes for degradation of phenol. Laboratory experiments are done on
adsorption of phenol on carbonaceous adsorbents as an effective advanced process
to treatment phenolic wastewater [14]. The moving bed biofilm reactor (MBBR)
is an alternative process design which utilizes the advantages of a biofilm reactor
and which at the same time can handle high loads of particles, phosphorus and
nitrogen removal, consumed most of the biodegradable organic matter and does not
incorporate return sludge [15].
The aim of this study was to investigate and compare the BOD5 removal
efficiency in (MBBR) and an activated sludge system (AS). This work also aims to
verify the reliability of Moving Bed Biofilm Reactor to treat municipal wastewater
in Iraq.
BIOFILM CARRIER
The core principal of the (MBBR) treatment process is the treatment of the
incoming wastewater by microorganisms growing in a biofilm on biocarriers
suspended in the liquor in the MBBR reactor. The biocarriers “carry” the
microorganism's through-out the reactors [6]. Most of the microorganisms in the
biofilm are heterotrophic (they use organic carbon to create new biomass), with
facultative bacteria predominating. Facultative bacteria can use the dissolved
oxygen in the mixed liquor. As the microorganisms populations grow and multiply,
the biomass on the biocarriers is thickened. Biomass thickening affects the ability
of dissolved oxygen and substrate in the reactor to “reach” all of the biofilm
microorganisms. Microorganisms in the outer layers of the biofilm have “first
access” to the dissolved oxygen and substrate diffusing through the biofilm [16].
As the dissolved oxygen and substrate diffuses through each subsequent layer in
the biofilm, more and more is consumed by the microorganisms in the preceding
biofilm layers. Part of the design of each (MBBR) reactor is an aeration system the
decrease of available dissolved oxygen through the biofilm produces aerobic,
anoxic and anaerobic layers in the biofilm [17].
In addition to providing the required oxygen, the aeration system ensures the
biocarriers are evenly distributed throughout the reactor. Extremely high turbulence
detaches biomass from the carrier and therefore is not recommended. In addition,
collision and attrition of media in the reactor causes biofilm detachment from the
outer surface of the media. Because of this, the (MBBR) carrier media is provided
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Eng. & Tech. Journal, Vol. 30 ,No. 9,2012 Wastewater Treatment in Baghdad City Using
Moving Bed Biofilm Reactor (MBBR)
Technology
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with fins on the outside to protect biofilm loss and promote growth of biofilm. The
surface area of the fins does not contribute to the specific area reported [18].
The effective area of the (MBBR) carrier medium was reported to be 70% of the
total surface area due to less attachment of biofilm on the outer perimeter of the
media.
MATERIALS AND METHODS
The laboratory scale biological system, a moving bed biofilm reactor (MBBR)
and activated sludge (AS) was constructed; a schematic diagram of the system is
given in Fig. (1) & Fig. (2), the system was operated for 6 months. Municipal
Wastewater from Al-Z'afarania domestic community in Baghdad was used for this
study; Table (1), with sludge obtained from AL-RUSTUMYIA wastewater
treatment plant as seed. The wastewater was pumped daily into the system from a
two 30-liter storage tanks (Batch process).
Figure (1) Moving bed biofilm reactor (MBBR) and
activated sludge (AS)
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Moving Bed Biofilm Reactor (MBBR)
Technology
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Influent
Effluent
MBBR reactor
Feed Tank Settling
Tank
Air flow
meter Sludge return
Activated sludge reactor
Aeration system Waste Sludge
Figure (2) Schematic diagram of the MBBR and activated
sludge (AS)systems used in this study
Table (1) Influent synthetic wastewater Specifications
No. Composition Concentration
1 TDS 1000 – 4000 mg/L
2 BOD5 150-1200 mg/L
3 TSS 800 mg/L
4 TKN 50 mg/L
5 NH4-N 1 mg/L
6 PO4-P 10 mg/L
7 pH 7-8
8 Temperature 20◦C
9 Fecal Coliform 4 *107
The pilot plant consisted of two 10-liter rectangular basin for each reactor in
parallel, constructed from Perspex, one for AS treatment and the other for MBBR.
These reactors followed by the 7-liter rectangular basin with a conical bottom
(Clarification /Settling Zone). The aeration system consisted of a manifold of 1/2
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Eng. & Tech. Journal, Vol. 30 ,No. 9,2012 Wastewater Treatment in Baghdad City Using
Moving Bed Biofilm Reactor (MBBR)
Technology
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inch (inner diameter) made from (Chlorinated Poly Vinyl Chloride) (CPVC pipe), a
vertical pipe connector to the manifold and rising above the liquid level in the
reactor to prevent flow of liquid to the compressor when the compressor was
turned off. A temperature resistant flexible tube was used to connect the vertical
pipe and the compressor. An airflow meter was installed to measure air supply to
the reactor. Air supply was maintained between 3.5 and 4 L/min. Valves mounted
on the compressor were used to regulate the airflow. The aeration system provided
coarse bubbles and kept the media (Kaldnes media) in suspension and circulation.
Stainless steel screen is provided at the outfall end of the reactor in order to keep
the biofilm carriers in the reactor. The biofilm (or biomass) grows on small carrier
elements suspended throughout the liquid in the reactor, biofilm carrier elements
(Kaldnes media) were used in this study referred to as biocarriers [8, 10].
Suspended media were made of high density polyethylene (density 0.95 g/cm³);
which has a density slightly less than water. The biocarrier (medium) is shaped in a
form of a wheel, Table (2) and has a height of (7mm) and diameter of (10mm), It is
reinforced in the inside with a cross members, which increase the available interior
surface area for biofilm attachment. The effective specific area of the medium is
500 m2 /m3 [8, 11].
One important advantage of the moving bed biofilm reactor is that the filling
fraction of biofilm carriers in the reactor may be subject to preferences. In order to
be able to move the carrier suspension freely, it is recommended that filling
fraction should be below 70% (volumetric filling of plastic elements in empty
reactor) [10, 19].
Table (2) MBBR carrier elements employed in the
experiments[10]
Material Polypropylene (density =
0.95 g cm-3)
Shape Cylindrical
Dimensions Height = 7mm
Diameter = 10 mm
Effective 500 m2/ m3
specific
surface
Area
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Moving Bed Biofilm Reactor (MBBR)
Technology
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BATCH EXPERIMENTS
Experiments were devoted to a performance comparison of the BOD5 removal
efficiency between MBBR & AS. The effluent from each reactor was individually
fed into the clarifier/Settling Zone downstream of the reactors to separate
suspended solids in the effluent stream for each reactor. It was decided to carry out
a comparison test at various BOD loads using pilot plant consisting of one MBBR
reactor and a one AS reactor corresponding settling tank, operated in parallel. In
the first part of the experiments (15-26) November, using municipal Wastewater
from Al-Z'afarania domestic community in Baghdad, the BOD5 load about (150-
200) mg/l, filling ratio of plastic elements in the MBBR reactor (volume occupied
by carriers in empty reactor) is 40%. The second part of the experiments (2-11)
December, using synthetic wastewater comprising glucose as the main organic
constituent plus balanced macro and micro nutrients and alkalinity, high BOD5
load about (1000-1200) mg/l, the MBBR reactor was filled about (67-70) %
(recommended percentage volumetric filling of plastic elements in empty reactor),
[19].
SAMPLING AND ANALYSIS
Samples were collected from influent and sampling port of each reactor daily
(different influent each day). Temperature, dissolved oxygen and pH were
measured in each reactor every workday, immediately before sampling. Sampling
bottles stored in a refrigerator for BOD5 analysis. The samplers were started at
8:00 AM and turned off at 3:00 PM.
RESULTS AND DISCUSSION
As noted above, the core principal of the MBBR treatment process is the
treatment of the incoming wastewater by microorganisms growing in a biofilm on
biocarriers suspended in the liquor in the MBBR reactor. The biocarriers “carry”
the micro-organisms throughout the reactors. Table (2) shows an AnoxKaldnes
biocarrier with biofilm growth. Biofilms are communities of microorganisms
growing on surfaces. The microorganisms in the biofilms are essentially the same
as those in suspended activated sludge wastewater treatment systems.
Fig. (3) show the soluble BOD removal with time using AS & MBBR
technologies. The temperature was 20ºC (filling ratio of plastic elements in the
MBBR reactor is 40%). It can be observed that the total BOD (TBOD) removal
rates in the MBBR reactor were higher than AS ones (for the same (TBOD load),
and this improvement increase with time. This explains the microorganisms grow
and multiply in the MBBR reactor; the decrease of available dissolved oxygen
through the biofilm layers produces aerobic, anoxic and anaerobic layers in the
biofilm. Different biological action occurs in each of those layers as specific
microorganisms grow in the different environments within the biofilm. In the upper
layers of the biofilm, where dissolved oxygen and substrate concentrations are
high, the micro-organism population will be aerobic higher level organisms.
Deeper into the biofilm, where the oxygen and substrate concentrations decrease,
in those layers "Nitrification" occurs, these results showed in Fig. (3), are
consistence with Moving Bed Biofilm Reactors performance reported in the
literature [5].
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Moving Bed Biofilm Reactor (MBBR)
Technology
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The main goal of biocarrier design is to provide a high internal surface area that
will promote biofilm growth in a protected environment. These carriers suspended
in liquid and kept in constant circulation by the aeration system of the reactor this
increases the surface area of contact between the organic matter and suspended
solids. Hydraulic retention time (HRT) = 7.5h.
BOD removal efficiencies versus operation period are shown in Fig.(4); the
average efficiencies for (TBOD) removal were 83 % for MBBR and 70% for AS.
Fig.(4) shows that the (TBOD) removal efficiencies was improved with time
(especially for MBBR because the growing of Biofilm increases on carriers media).
Finally achieve effluent quality with BOD5 less than 30mg/l according to the
normal standard of Biological treatment.
200
150
BOD5(mg/l)
100
50
0
1 2 3 4 5 8 9 10 11 12
Time (days)
Inffluent Effluent (AS) Eff. MBBR (40%)
Figure (3) BOD5 removal with time using AS & MBBR(40%)
technologies during the first set of experiments (15 – 26 NOV.)
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Technology
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100
90
80
BOD removal efficiency (%)
70
60
50
40
30
20
10
0
1 2 3 4 5 8 9 10 11 12
Time (days)
Activated slludge MBBR (40%)
Figure (4) BOD removal efficiencies versus Time using (MBBR (40%)
& (AS) during the first set of experiments (15 – 26 NOV.)
In the second part of the experiments, by increasing the number of plastic
carrier’s medium (Moving Bed Biofilm reactor was filled about (67-70) %), Fig.
(5) shows clear preference of the moving bed biofilme reactor technology against
activated sludge process especially for high BOD5 load under 8 h HRT,
temperature was 20ºC, pH and dissolved oxygen are (7-8), 7mg/l respectively. The
volumetric removal rate in the MBBR is several times higher than that in the
activated sludge process.
Fig.(6) shows that at the beginning of the experiment, (TBOD) removal rate
was very low but after 4 months of the study, it reached 88% at HRT = 8h. This is
due to the fact that microorganisms grow in a biofilm on biocarriers suspended in
the liquor in the MBBR reactor. As the biofilm grows a natural “sloughing” of the
biofilm off the biocarriers occurs. That sloughing maintains the biofilm at a
thickness supported by the incoming organic load. i.e the (TBOD) removal
efficiencies from day to day was improve.
The results shown in Fig. (6), are consistence with Moving Bed Biofilm
Reactors performance reported in the literature [11].
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Technology
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1400
1200
1000
BOD5(mg/l)
800
600
400
200
0
1 2 5 6 7 8 9 10
Time (days)
Influent Effluent (AS) Eff. MBBR (70%)
Figure (5) BOD5 removal with time using AS & MBBR(70%)
technologies during the second set of experiments (2 – 11 DEC.)
100
95
90
BOD removal efficiency (%)
85
80
75
70
65
60
55
50
1 2 5 6 7 8 9 10
Time (days)
Activated sludge MBBR (70%)
Figure (6) BOD removal efficiencies versus time using (MBBR (70%)
& (AS) during the second set of experiments (2 – 11 DEC.)
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Moving Bed Biofilm Reactor (MBBR)
Technology
.
CONCLUSIONS
Moving Bed Biofilm Reactors (MBBRs) were tested for biological pretreatment
of a municipal Waste-water from Al-Z'afarania domestic community in Baghdad.
In The first part of the experiments, BOD5 load was about (150-200) mg/l, the
wastewater had an easily biodegradable fraction of 60 to 80% of BOD5 removal
(for AS & MBBR) respectively. In The second part of the experiments when BOD5
load was about (1000-1200) mg/l the removal efficiencies of BOD reached 88% for
MBBR and about 70 % for AS.
The MBBR treatment process can offer numerous advantages over a suspended
growth activated sludge treatment process. Those advantages include:-
● Denser treatment population per unit volume. That often translates into smaller
treatment volumes (i.e. smaller foot print) and greater capacity to successfully treat
incoming organic loads.
● High Loading Conditions with very little operator intervention, overall cost of
operation and maintenance may be lower than the AS system.
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