1. The document discusses the water treatment process at the Durgapur Municipal Corporation water treatment plant in Angadpur. It involves 7 stages: screening, prechlorination, aeration, flocculation, sedimentation, filtration, and disinfection. 2. Key steps include adding aluminum sulfate and polyelectrolyte to form flocs, sedimentation to remove flocs, sand filtration, and chlorination for disinfection. Additional steps are aeration, pH adjustment with lime, and post-chlorination before distribution. 3. The water treatment plant, pumping stations, and distribution network were installed in two phases to supply water to Durgapur town.

1. PROJECT ON WATER TREATMENT PLANT IN DURGAPUR MUNICIPAL
CORPORATION, ANGADPUR
DONE BY
ASHUTOSH KUMAR
ROLL NO. 12/BT/57
BIO TECHNOLOGY
NIT DURGAPUR

2. Introduction
• Since ever, nature is able to provide high quality drinking water. But
contamination, modifications and overexploitation of the natural water
resources make clean water to a more and more scarce and precious
treasure. To preserve this treasure for future generations is one of the
most important tasks. Water science, water management and water
technology has to play a dominant role in designing our social and
industrial structure for tomorrow. Most of the knowledge, the
experience, the skills and tools that are needed are available.
• Suitable concepts and solutions in water technology are based on
several scientific and engineering branches as hydrology, hydrogeology,
hydrobiology, water chemistry, microbiology, fluid mechanics, civil,
mechanical, electrical and chemical engineering. Water and wastewater
technologies interfere with natural processes and should be designed,
operated and controlled in a way, which does not stress the hydrological
cycle..

3. The Need for Wastewater
Treatment
• Wastewater treatment is needed so that we can use our rivers and
streams for fishing, swimming and drinking water. Increases in both the
quantity and variety of goods produced can greatly alter the amount
and complexity of industrial wastes and challenge traditional treatment
technology. The application of commercial fertilizers and pesticides,
combined with sediment from growing development activities,
continues to be a source of significant pollution as runoff washes off the
land.
• Water pollution issues now dominate public concerns about national
water quality and maintaining healthy ecosystems. Sewage is a major
carrier of disease (from human wastes) and toxins (from industrial
wastes). The safe treatment of sewage is thus crucial to the health of
any community.
• Micro pollutants in wastewater are a challenge to wastewater
professionals. The presence of contaminants in Waste Water Treatment
Plant effluents may cause a severe risk for the drinking water
preparation. Upon discharge of the effluent into the receiving water
body dilution and further degradation will occur.

4. Source of Raw water
Surface i) River ii) Reservoir iii) Dam iv) Lake v) Canal.
Ground i) Well ii) Tubewell iii) Infiltration well/gallery

5. GENERAL PRINCIPLES AND TREATMENT STAGES
• Water treatment plants treat surface water from the dams. Raw water contains suspended and
inorganic material, plant material, bacteria, protozoa, algae, gases etc. In order to remove all these
foreign particles from the water and make the water suitable for drinking purposes the following
procedures should be carried out:
• Removal of suspended matter.
• Decolourisation and oxidisation of the inorganic material and killing of all pathogenic micro-organisms
by adding chlorine (prechlorination).
• Aeration of water.
Raw water reservoir
• Flocculation of colloidal/organic matter with
aluminium sulphate and anionic polyelectrolyte.
• Sedimentation.
• Filtering.

7. 1.Screening (Removal of suspended matter)
Suspended matter present in the water like leaves, water plants, soil etc. is retained at
the raw water reservoir of the treatment plant.
•Removes large solids
logs
branches
rags
fish.
•Simple process
may incorporate a mechanized trash removal system.
•Protects pumps and pipes in Water Treatment Plants.
2. Prechlorination
Chlorine has oxidising and disinfecting properties. With the addition of chlorine the
various organic and inorganic materials like iron, hydrogen sulphide etc. are oxidised
and all the pathogenic and other micro-organisms are killed or inactivated.
Chlorine is present at all stages of water treatment in order to ensure that there is no
development of pathogenic micro-organisms.

8. 3. Aeration of Water
Air is added to the water in order to kill all anaerobic micro-organisms and to oxidise the
organic material present in the water.
4 . Flocculation
•Small particles are not removed efficiently by sedimentation because they settle too
slowly
•they may also pass through filters
•easier to remove if they are clumped together
•Coagulated to form larger particles
•Addition of aluminium sulphate
The addition of aluminium sulphate is necessary in order to remove the organic
particles present in the raw
water and to change the colour of the water from green to clear. The aluminium sulphate
attacks the
colloidal particles of the water and flocs are formed. As these flocs are heavier than the
water molecules,
they gradually settle down to the bottom of the reservoir as the sludge.

9. . Addition of anionic polyelectrolyte
The addition of anionic polyelectrolyte helps the aluminium sulphate to react more
quickly with the organic matter. Larger and heavier organic flocs are formed, which
settle much more easily, in a period of 2 to 3 instead of 6 to 8 hours.
The addition of anionic polyelectrolyte is done in cases when the aluminium sulphate
doesn't react quickly with the organic matter, especially at low temperatures in winter,
in spring, when the raw water contains big quantities of algae and in the autumn
when the water is very turbid, especially after very heavy rainfall.

10. 5. Sedimentation
After the addition of aluminium sulphate and polyelectrolyte the flocs settle down, as
sludge, in the sedimentation tanks. The sedimentation tanks are sometimes called
clarifiers because here, the water is being clarified. The removal of sludge is done on a
daily basis and the sludge is transferred to the sludge drying beds, while the water is
transferred to the filters.

11. 6.Filtering
After the sedimentation tanks, the water
passes through special rapid sand filters
where it is filtered in order to remove all the
remaining flocs/particles which are present
in the water..
•The filtration apparatus is a concrete box
which contains sand, gravel and underdrain.
•After the filter is operated for a while, the
sand becomes clogged with particles and
must be backwashed
•Flow through the filter is reversed and the
sand and particles are suspended
•The particles are lighter than the sand, so
they rise up and are flushed from the
system. When backwashing is complete, the
sand settles down onto the gravel, flow is
reversed and the process begins again.

12. Disinfection:
•With particles removed, it only remains to provide disinfection, so that no pathogens
remain in the water
•Protozoan pathogens are large in size and have been removed with other particles
•Bacteria and viruses are now destroyed by addition of a disinfectant
Chlorination
•Enough chlorine is added so that some remains to go out in the water distribution
system, protecting the public once the water leaves the plant.
.

13. 7. Addition of lime
Lime is added to the water to correct its acidity (pH).
•Areas where water comes into contact with limestone, there may be high levels of
calcium and magnesium present
•these chemicals make the water "hard“
•Hardness is removed by a process called softening
•Two chemicals (lime, CaO and soda ash, Na2CO3 ) are added to water
•causing the calcium and magnesium to form precipitates
•solid substance is then removed with the other particles by sedimentation and filtration.
8. Postchlorination
After the water treatment process is completed, chlorine is again added to the water to
ensure that there is no growth of any pathogenic micro-organisms in the water
supplied to the Water Boards etc. The quantity of chlorine is much less than the quantity
added during the prechlorination stage.

14. Water Supply
provided by DMC
In existing water supply system of Durgapur town,
Durgapur Municipal Corporation provides water
supply to the major part. The infrastructure
available with DMC includes treatment plant at
Angadpur, Clear water Reservoir and Pump house
at Angadpur, CWR and Booster pumping station at
Piyala, Service Overhead reservoir at various
localities, connecting rising main pipeline and
distribution network from OHR.
The Treatment plant, Rising main pipeline,
Booster Pumping stations, OHR and distribution
network, which are in existence today, have been
installed through the Public Health Engineering
Directorate in two phases. Extension of the
distribution network to cover added areas to
meet shortfall in demand have been carried out
by DMC from time to time.