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I HAVE SHARED ALL MY PRACTICAL WATER TREATMENT EXPERIENCES WITH SOLVED EXAMPLE HERE SO THAT ANYBODY CAN USE IT.
SEARCH THIS BLOG BELOW FOR ENVO ,COMPACT STP,ETP,STP,FMR,MBBR,SAFF,IRON,ARSENIC,FLUORIDE,FILTER,RO,UASB,BIO GAS,AERATION TANK,SETTLING TANK,DOSING,AMC.
ENVO IS WORKING IN THIS FIELD SINCE 1994. An introduction to MBBR (moving
bed biofilm reactor )/ FM Reactor/ FAB /FMR Reactor sewage
treatment plant (STP)
THIS PLANT IS USED TO TREAT DIRTY WASTE WATER COMING OUT
FROM ANY PLACE BEFORE RELEASING IT TO DRAIN. GOVERNMENT DOES NOT ALLOW
UNTREATED DIRTY WASTE WATER TO BE RELEASED TO DRAIN DIRECTLY WITHOUT TREATMENT, IT IS
CALLED WATER POLLUTION.
WHERE THIS PLANT IS REQUIRED
1. Land
development-housing colony, hotels,Restaurants, resorts, office complexes,Multistory Buildings, Malls
CHARACTERISTICS OF DIRTY WASTE WATER COMING TO
STP: pH --8 TSS--300 ppm Oil & Grease --50 ppm BOD--250 ppm COD 650 ppm
CHARACTERISTIC OF TREATED WATER GOING OUT
OF STP TO DRAIN
pH --8
TSS--less than 100ppm Oil & Grease --less than 10 ppm BOD--less than 30 ppm COD less than 250 ppm
ENVO COMPACT MBBR STP is a complete unit,
pre-piped, pre-wired and ready to install. Engineered to serve with minimal
maintenance, and designed to meet the requirements of the state water quality
agency. Epoxy or other chemically resistant coatings, together with dependable
accessory equipment assure long life and low maintenance cost. And the
best part is the resale value. These total units can be re-located to serve
again.
Features of COMPACT STP
o Pre-engineered and prefabricated
structure
o Easily transported to the site
o Modular design allows easy
installation
o Simple operation-less manpower
required
o User friendly-low maintenance
o Long service life,
o Custom designed
o Efficient process, REDUCES BOD LOAD BY MORE THAN 80%
o World-class finishing
o Sludgecan be used as manure for horticulture purpose
o Branded electrical/mechanical
equipments used
o Good resale value
The Process of Treatment
Primary Treatment (DEWATS/Collection tank before COMPACT MBBR)
In primary treatment, floating and suspended solids are
settled and removed from sewage by bar screen. Following this, discharge from
the sewers enters a DEWATS/collection chamber .
Secondary Treatment (COMPACT MBBR )
This is the next level treatment where the bacteria in
sewage are used for further purification of the sewage. It’s a biological
process that removes about 85% or more of the organic matter in sewage compared
with primary treatment, where the purification level is about 50%. These
processes are variations of what is called the "Activated
Sludge" process, which provide a mechanism for bacteria, with air
added for oxygen, to come in contact with the wastewater to purify it.
In the activated sludge process, flow from the sewer goes
into the reactor, where compressed air is mixed with sludge in the presence of
synthetic media on which the purifying organisms grow and contact the
wastewater, removing contaminants in the process. The activated sludge allows
bacteria to feed on the "food" provided by the new wastewater in the
reactor, thus purifying it.
The flow, along with excess organisms that build up on
the media during the purification, then goes to a Tube Settler. Air flows up
through the media in the filters, to provide necessary oxygen for the bacteria
organisms. Clarified effluent flows to the receiving water, typically a river ,
after disinfection. Excess sludge is produced by the process and after
collection from the bottom of the tube settler it is dewatered, sometimes after
mixing with primary sludge, for use as fertilizer, disposed of in a landfill,
or incinerated.
Tertiary Treatment
Advanced level of water treatment is called tertiary
treatment of water - where heavy metals, toxic chemicals and other pollutants
are removed from wastewater to an altering degree. The tertiary treatment
methods include micro filtration, carbon adsorption, evaporation/distillation,
and chemical precipitation.
Civil Works:1.DEWATS(Collection tank),2..SDB,3.Treated
water tank 4.Foundation for compact
SPECIAL FEATURE OF OUR DESIGN:
We provide two-stage treatment. DEWATS is the first stage
treatment. Because of DEWATS, the blower capacity is reduced in the second
stage of MBBR treatment thereby reducing the maintenance cost during running of
the STP..
An introduction to MBBR (moving bed biofilm reactor )/
FM Reactor/ FAB /FMR Reactor wastewater treatment
When communities of
microorganisms grow on surfaces, they are called biofilms. Microorganisms in a
biofilm wastewater treatment process are more resilient to process disturbances
compared to other types of biological treatment processes. Thus, biofilm
wastewater treatment technologies can be considerably more robust especially
when compared to conventional technologies like activated suldge process..
In the MBBR biofilm
technology the biofilm grows protected within engineered plastic carriers,
which are carefully designed with high internal surface area. These biofilm
carriers are suspended and thoroughly mixed throughout the water phase. With
this technology it is possible to handle extremely high loading conditions
without any problems of clogging, and treat industrial and municipal wastewater
on a relatively small footprint.
System
description
The MBBR biofilm
technology is based on specially designed plastic biofilm carriers orbiocarriersthat are suspended and in continuous
movement within a tank orreactorof specified volume. The design of
associated aerators, grids, sieves, spray nozzles and other integral parts to
the reactor is also of great importance in making up the system as a whole .
The industrial and
municipal wastewater is led to the MBBR treatment reactor where biofilm,
growing within the internal structures of the biocarriers, degrade the
pollutants. These pollutants that need to be removed in order to treat
the wastewater are food orsubstratefor growth of the biofilm. The
biocarrier design is critical due to requirements for good mass transfer ofsubstrateand oxygen to the microorganisms
. Excess biofilm sloughs off the biocarrier in a natural way .
An aeration grid located at the bottom of the reactor supplies
oxygen to the biofilm along with the mixing energy required to keep the
biocarriers suspended and completely mix within the reactor.
Treated water flows from
reactor through a grid or a sieve, which retains the MBBR biocarriers in the
reactor. Depending on the wastewater, the reactors are may be equipped with
special spray nozzles that prevent excessive foam formation.
The MBBR is a biological aerobic degradation of organic
pollutants. The process utilizes millions of tiny, polyethylene biofilm
elements that provide a high surface area as a home for a vast, highly active
bacteria culture. This fixed film process features a flexible reactor design,
the ability to handle load increases without the need for extra tankage, and
remains stable under large load variations, including temperature, strength or
pH. Like the activated sludge process, the MBBR process utilizes the whole
volume of an open tank. Unlike an activated sludge reactor,it
does not require sludge return to operate effectively. In MBBR ,
addition of media quantity and Air Quantity is the Key Factor.
Total reactor volume of the MBBRs is designed for different
hydraulic retention time for different types of waste water at average flows
and than checked against peak flows. Essentially nutrient levels and DO levels
are the only control points for the system.
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
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 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 DEWATS 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.
Calculations!:Aeration Tank
Volume, HRT, MLSS Values.
I am working in a STP &
ETP plant. I need to know how to calculate:
1. Volume of Aeration tank
2. HRT
3. F/M Ratio
4. MLSS value.
The relevant details of the ETP
are as below:
Influent flow = 10 m3 / day
In. flow BOD = 1200 mg / L
In.flow COD = 2200 mg / L
TSS = 850 mg / L
Jeyaroopa
jeyaroopa79@gmail.com
Dear Jayroopa
You may please refer Water &
Waste Water Engineering by Metcalf & Eddy.
BOD of effluent is 1200 mg/l. It
will be difficult to bring down the BOD by Activated Sludge process to
desire permissible limits.
Simplified method of calculation
is as below.
Process Activated sludge
Flo3, CUM 10
Type Extended aeration
Food to Microorganism ratio
(F/M) 0.15
Total BOD load, Kg
BOD*Flow/1000.= 12
Total mixed liquor suspended
solids(MLSS) Total BOD/(F/M) = 80 kg
MLSS in Tank say mg/l 3000
Volume of tank, CUM Total
MLSS/(MLSS/1000) = 26.6
Retention time, hr 24*Volume of
Tank/Flow = 63.84
You can select F/M &
MLSS values and optiimise the volume of a tank.
The waste water has high
suspended solids therefore sedimentation is must.
Maximum efficiency of Activated
sludge process is 95% therefore if you need lower value of BOD in treated
effluent then you have to opt two stage process.
For further information please
contact
Prof. R. V. Saraf
Director
Viraj Envirozing India Pvt. Ltd.
21 Radhakrishna Near SBI, Paud
Road, Pune 38
watersgs@vsnl.net
13 Aug, 2008 | Taral Kumar
Dear Jeyaroopa,
Though the calculation is not
that simple, I will give you a thumb rule. Multiply BOD with Quantity of
effluent and divide it by 500 to get aeration tank volume. For example, for
10 cum/day with 1200 BOD, aeration tank volume shall be 10 x 1200 / 500 = 24
cum. That is 2.5 days storage nearly. But that is because the BOD is
excessively high.
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.
ITEMS OF ENVO COMPACT
MODULE
Sr
No
Item
Specification
Qty
Cost
1
Raw
Sewage Pump
Submersible,auto running,kirlosker
1 No
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
3
Diffuser
in Aeration Tank-I & II
Dome
type,Make:ENVO
LOT
4
Floating
Media in aeration tank-I & II
LOT
5
Tube
Deck Media in Tube Settler
LOT
6
Air
Blower,
Twin lobe Rotary type, Make: SGN
1 No
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
Environmental Entrepreneur,Green Biz.NRN Murthy of Infosys says that we Indians are weak in execution.We need to realize the need and practice of gud project management. Form a group of competent Managers,Give them responsibilities and review the project from day One.