Sewage Treatment Plant
Sewage Treatment Plant
Sewage Treatment Plant
A VISIT REPORT ON
“SEWAGE TREATMENT
PLANT”
TAPOVAN, NASHIK
DATE OF VISIT:-23rd Jan 2019
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 1
Sewage Treatment Plant
To study the various units of sewage treatment plant & to know various
chemical & biological processes used for the treatment of sewage waste water.
Description
The sewage treatment plant having the capacity of 130 MLD. The plant
collect waste water coming from residential zone. The total initial cost of the plant
is about 43 crore. The sewage water collected from mhasarul, hirawadi, new
ganesh wadi & kapila.from this plant 500 to 600 unit electricity power is
generated. After collecting sewage water by pumping from the places they are
passed through screening chamber & all the solid particles in water are removed
either by mechanically or by manually.
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Sewage Treatment Plant
1) Physical Process
2) Biological Process
3) Chemical Process
1 PHYSICAL PROCESS:
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Sewage Treatment Plant
the main purpose of gritting is to settle the solids & after particle having greater
density which is settle at down or bottom.
Fig.3 SCREENING
2. BIOLOGICAL PROCESS
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Sewage Treatment Plant
Hp from which the water is circulated from top to bottom so that increase the O2
in water.
The inlet chamber consist of waste water which is treated through the
process which include waste water from different areas of Nashik city i.e.
mhasarul, hirawadi. Waste water is pumped & carried out for the process of
screening. The screening is done by either mechanically or manually.
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 5
Sewage Treatment Plant
Sewage contain both type of material namely organic & inorganic. The
purpose of providing grit chamber in sewage treatment process is to remove grit,
sand & such other inorganic matter from sewage. In general grit chamber are
placed after pumping station & before the screen. The detention time of water is
10 to 15 min.
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Sewage Treatment Plant
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Sewage Treatment Plant
3. Up flow velocity.
4. Reactor volume.
5. Physical features.
6. Gas collection system (Methane gas is collected which is used to generate
electricity.)
After water is treated in UASB reactor, it’s carried out for the process of
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Sewage Treatment Plant
aeration tank. This process aims at bringing water in intimate contact with air. In the
process of aeration oxygen is absorbed by water and carbon di oxide is liberated. The
aeration easily removed hydrogen sulphide and hence the odour due to this gas is
removed by aeration. Detention period of aeration tank is 16.5 hr. depth of aeration
tank is 6.5m.
Fig.
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 9
Sewage Treatment Plant
Drying beds are typically composed of four layers consisting of gravel and
sand. The first layer is coarse gravel that is 15 to 20 centimetres thick. Followed
by fine gravel that is 10 centimetres thick. The third layer is sand that can be
between 10 to 15 centimetres and serves as the filter between the sludge and
gravel. Sludge dries up and water percolates to the first layer that is collected at
the drainage pipe that is beneath all layers.
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 10
Sewage Treatment Plant
4. GRIT CHAMBER
Grit chambers are basin to remove the inorganic particles to prevent damage
to the pumps, and to prevent their accumulation in sludge digesters.
Settling Velocity
v=g(Ss-1)d2
For grit particles of specific gravity 2.65 and liquid temperature at 10°C, u=1.01
x 10- 6m2/s. This corresponds to particles of size less than 0.1 mm.
Transition law:
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Sewage Treatment Plant
• Stoke's law:
• v=g(Ss-1)d
Stoke's law holds good for Reynolds number,Re below 1.
Re=vd
u
For grit particles of specific gravity 2.65 and liquid temperature at 10°C, u=1.01
x 10- 6m2/s. This corresponds to particles of size less than 0.1 mm.
• Transition law: The design of grit chamber is based on removal of grit
particles with minimum size of 0.15 mm and therefore Stoke's law is not
applicable to determine the settling velocity of grit particles for design purposes.
v2=4g(rp-r)d
Where, CD= drag coefficient Transition flow conditions hold good for Reynolds
number,Re between 1 and 1000. In this range CD can be approximated by
CD=18.5
Re0.6 (vd/u)0.6
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 12
Sewage Treatment Plant
CONCLUSION
From this visit we came to know the thorough study about the introduction,
principle, design, initial & final parts in sewage treatment plant. This visit is really
helpful for our future studies, we studied the working process of sewage treatment
plant & organizational work.
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Sewage Treatment Plant
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Sewage Treatment Plant
REFERANCE
Mr. S.G.Rangwala
2) Study of sewage treatment plant-Mr. K.S. Rangwala
3) https://nptel.ac.in
4) emmer, Frank N. (1979). The Nalco Water Handbook. New York: McGraw-Hill
Book Company.
5) Patterson, James W. (1980). Wastewater Treatment Technology. Ann Arbor,
Michigan: Ann Arbor Science. ISBN 0-250-40086-3.
6) Ramseur, Jonathan L. (September 22, 2017). Wastewater Infrastructure:
Overview, Funding, and Legislative Developments (PDF). Washington, DC:
Congressional Research Service. Retrieved 17 December 2017.
7) Reed, Sherwood C.; Middlebrooks, E. Joe; Crites, Ronald W. (1988). Natural
Systems for Waste Management and Treatment. New York: McGraw-Hill Book
Loknete Goplaroji Gulve Polytechnic, Vilholi, Nashik, Dept. of Mechanical Engineering Page 15