The document is a seminar presentation on water pollution given by Dennis M. Mondah at Davangere University under the guidance of K.L Soumya. It discusses the types, sources, and effects of water pollution as well as methods of control and wastewater treatment. The major sources of water pollution identified are sewage, industrial effluents, agricultural runoff, mining, and solid waste. Water pollution reduces water quality and makes it unsuitable for drinking, domestic, and industrial uses while also harming aquatic ecosystems. Proper wastewater treatment and regulation of polluting activities are needed to control water pollution and its negative effects.

1. DAVANGERE UNIVERSITY.
Department of studies in Microbiology
Seminar Topic On: WATER POLLUTION.
Presented By:
Dennis M.
Mondah
M.sc 1 Semester
Dept. of
Under the guidance of:
K. L Soumya
Dept. of
Microbiology.

2. CONTENTS:
• Introduction
• Classification types of water pollution
 Surface water pollution
 Underground water pollution
• Sources of water pollution
 1. Point sources of water pollution
 2. Non point sources of water pollution.
• Effects of water pollution
• Control and prevention of water pollution
• Waste water treatment;
• Tickling filters
• Summary
• Conclusion
• Reference

3. INTRODUCTION.
 Water pollution can be defined as the alteration in the
physical, chemical or Biological characteristics of water so
that it either becomes a health hazard or unfit for use.
 Water pollution is the contamination of water bodies due to the
anthropogenic activities thereby reducing its quality and
composition hence it becomes less suitable for drinking
domestic use, industrial use or it undergoes a shift in its ability
to support its biotic communities such as fish, microorganisms,
etc..
 Toxic substances from farms, homesteads, municipal sewer
lines and factories readily dissolve into water bodies where
they mix with water therefore degrading its quality therefore
contaminating groundwater and surface water sources.
 Pollutants may be; solid wastes, soil sediments microbial
pollutants, heavy metals, chemicals thermal and radioactive

4. TYPES OF WATER POLLUTION
1. Surface water pollution- This is when the
water on the surface of the earth gets polluted.
E.g. Estuaries, Rivers, ponds, Lakes, seas,
and oceans.
2. Underground water pollution- This is the
pollution which occurs to the water below the
earth’s surface. E.g. Aquifer (underground
storehouse of water)

5. SOURCES OF WATER POLLUTION
- Sources of water pollution can be classified into;
1. Point source of water pollution.- This refers to
the contaminants that enter the water bodies
from a single traceable source such as a pipe or
water channel for example discharges from
sewage treatment plant, industrial effluents.
2. Non-point sources of pollution- This is
the diffusion of contaminants into water bodies
from various sources that can not be traced to a
single discrete source E.g. Leaching of
fertilizers, herbicides and insecticides from
agricultural fields, storm water runoff,

6. Point Source Water Pollution

7. Non point sources of water pollution.

8. SOURCES OF WATER POLLUTION
Common sources of water pollution include;
Wastewater and Domestic Sewage.
Industrial effluents
Leaking sewerage lines
Mining Activities and Sedimentation
Solid waste and Nuclear waste
Agricultural activities
Thermal water pollution

9. DOMESTIC SEWAGE AND WASTEWATER.
• Domestic or industrial Used water is termed as
waste water and it is discharged in a common
public sewerage system.
• This wastewater includes sullage that is
wastewater from bathrooms, kitchen, washing
places and washing basins etc.
• Sewage contains human and animal excreta,
food residues, cleaning detergents, chemicals,
oil and grease, and other wastes. Also
microorganisms are present with other organic

10. INDUSTRIAL EFFLUENTS & WASTES.
• Industries produce a tremendous amount
of wastes which contains toxic chemicals
and other biological pollutants.
• The composition of industrial waste is
highly variable from industry to industry
and the capacity of the industry to
process its waste water.
• Effluents from the industries contain
dissolved chemicals and metals that

11. Industrial Effluents.

12. LEAKING SEWERAGE LINES
• It is reported that 75 – 80% water pollution is
caused by domestic sewerage which is mostly
untreated In cities and municipalities where the
sewerage systems are not well maintained .
• Some sewage delivery systems are blocked
due to solid wastes and sediments from the
construction sites.
• Most of the damage to the sewerage lines is
caused during regular road constructions and
also the building of houses where the debris

13. Blocked and Broken Sewerage Pipes

14. MINING ACTIVITIES & SEDIMENTATION.
• When elements are extracted fro the earth’s crust in the
raw form they contain harmful elements which when
they mix up with water they cause huge health
problems.
• It impacts fresh water through contamination by heavy
usage of water in ore processing and the mining
effluents seepage from tailings and waste rock
impoundments.
• Some inorganic chemicals used in the final extraction
and purification of the products find their way into the
water sources as effluents and waste water.
• Oil an grease leakage from the oil fields can cause
serious pollution as they float on the water surface

15. Coal and Oil mining

16. SOLID WASTE & NUCLEAR WASTE
• As water comes into contact with decomposing solid waste it dissolves both the
organic and inorganic wastes producing a polluted liquid known as leachate whose
concentration increases as it seeps deeper into the soil layers of the landfills it forms
a light brown or black colored leachate with a horrible stench and also enriches the
water with nutrients encouraging eutrophication.
• This leachate is rich in dissolved organic and inorganic contaminants and other
toxic metals which can lead to chronic toxin accumulation in aquatic organisms
which can consequently affect human beings who feed on them e.g. Prawns, fishes
and crabs.
• Trash floating on the water surface harms the physical habitats threatening the
aquatic life.
• Radioactive wastes upon discharge into water sources it enters into chemical
reactions that result in precipitates containing radionuclides which settle in the
water ad when it is consumed the radiations cause adverse effects in the body
systems of the aquatic organisms and humans.
• This impacts the plants that depend on this water for their growth and development.
• Water acts as a diluent. While there may be significant quantities of
radioactive material released into the sea near the Fukushima reactor site,

17. Nuclear wastewater seeping into
oceans.

19. AGRICULTURAL ACTIVITIES.
• With the increase in the world population man has to farm more and more
in order to sustain the food requirements of the people.
• These farming activities have led to environmental destruction which has in
turn caused water pollution.
• The increased use of inorganic fertilizers, pesticides and herbicides has
greatly polluted the water sources through leaching and run off water. The
substances from these inorganic fertilizers have increased the nutrient
levels in water causing the growth of phytoplankton and algal blooms
• Land clearing for more cultivatable land has exposed the bare soil to
erosion which causes sedimentation in the rivers and dams.
• Waste water from the dairy farms mainly sludge ( a mixture of cow dung
and urine) contains a large number microorganisms and it is rich in
nutrients. When it enters the water sources it creates a bad smell making the
water unsafe for human consumption and for domestic use.
• Some of the farming practices such as flooding irrigation used in the rice
paddy fields can lead to the accumulation of selenium that occurs naturally

21. THERMAL WATER POLLUTION
• Thermal pollution decreases water quality through any process
which causes changes in ambient water temperature. Water
drawn to keep machines cool, and then returned at a higher
temperature can have large effects on water quality.
• Warmer temperatures reduces level of dissolved oxygen in
water. It causes organisms to migrate and the activities of fish
life including nest building, hatching, spawning, reproduction.
• Main sources of this type of pollution include Nuclear power
plants, coal fired plants, industrial effluents, and hydroelectric
power.
• Domestic Sewage water which enters bodies of water with
minimal or no treatment will have a higher organic
temperature that alters the temperature of the water it enters.

23. EFFECTS OF WATER POLLUTION
• Water pollution causes great effects in the environment. Some
of these effects are:
 Destruction of biodiversity and aquatic habitats.
 Eutrophication- this is he increase in nutrients of the water
sources.
 Water turbidity increases due to very fine suspended mater.
 Change of color and smell due to contamination
 Large spread of infectious diseases.
 Bioaccumulation and bio-magnification- accumulation of toxic
substance in the tissues of tolerant organism.
 Spread of diseases e.g. Minimata diseases, Blue baby
syndrome, methaemoglobinemia.

24. CONTROL OF WATER POLLUTION
• Wastewater and sewage should be well treated.
• Industrial effluents should be treated at the source before it is
released to enter water sources or sewage systems.
• Avoid the heavy use of inorganic fertilizers, pesticides and
herbicides.
• Practice safe agricultural methods such as less water in irrigation
than flood irrigation method.
• Regular repair of sewage transmission pipes.
• Regulation and ensure safe mining activities and avoid runoff water
from mining pools.
• Solid waste and nuclear waste material should be properly disposed.
• Cooling water from industries and power generation stations should
be well cooled.
• Use nitrogen fixing plants instead of inorganic fertilizers.
• Oil spills and grease should be cleaned by using sustainable
methods.
• Water hyacinth can purify water by taking toxic chemicals and

25. WASTEWATER TREATMENT.
• Wastewater treatment is a process used to remove contaminants
from wastewater or sewage and convert it into an effluent that can be returned to
the water cycle with acceptable impact on the environment and human health.
• Wastewater treatment processes are many and varied though they can be applicable
to two separate establishments
1). A single dwelling unit- Septic tanks
2). Municipal treatment processes- primary, secondary , advanced and final
treatments.
• Primary wastewater treatment includes. Sedimentation which aims to remove
coarse solids and provide the concentration and collection of sludge.
• Secondary treatment mostly involves the microbial or biological treatment which
may be by use of trickling filters, activated sludge processes (flocculation) and
oxidation ponds
• Advanced treatment aims to remove nutrients, simple organic substances and
complex synthetic compounds this can be done by physical- chemical methods that
include biological nitrification- denitrification, filtration, reverse osmosis, carbon
adsorption, chemical addition and ion exchange.

26. INDUSTRIAL EFFLUENT TREATMENT
SET UP

27. SECONDARY WASTEWATER TREATMENT
(BIOLOGICAL METHODS).
• This is the biological method of waste water
treatment which involves the use of microorganisms
to remove the organic matter through oxidation as
they utilize the waste matter as they multiply in
population.
• The increased microbial mass can be removed from
the system as sludge and be separately treated and the
resulting effluent will contain a small amount of
inorganic salts resulting from the respiration activities
of the living organisms.
• Different methods of biological treatment of
wastewater are:

28. BIOLOGICAL BEDS- TRICKLING FILTERS.
• The trickling filters are used as biological method to remove organic
materials from wastewater.
• A trickling filter consists of abed of highly permeable media to which
microorganisms attach and wastewater percolates through.
• The liquid sewage water is sprayed over the surface of the bed either by a
rotating arm or through nozzles.
• The filtering medium of the tank becomes coated with a microbial film
called zoogleal film consisting bacteria, fungi , protozoa and algae.
• As the sewage seeps over these surfaces the microorganisms adsorb and
metabolize the organic constituents to more stable end products.
• After settling of the living mass is removed as sludge the final effluent is
largely free of organic matter although it will still contain inorganic salts
and the products of the respiratory activities of the microorganisms.
• The sloughed solids are transported to the secondary clarifier as the effluent
passes through the under drain system to the next processing unit where it
will undergo further treatment or be released into the water sources.

29. Advantages of trickling filter.
1. It is a simple, reliable biological method
2. It is suitable in areas with less land mass
3. It is highly effective in treating organic matter
4. It can withstand shock while loading
5. It rapidly reduces soluble BOD in applied
wastewater.
6. The elements used in the process are durable.
7. It is a low power requirements and needs
moderate level of skill and technical expertise

30. Disadvantages of Trickling Filters.
1. Additional treatment ay be required to
meet a more stringent discharge
standards.
2. There is a possible accumulation of
excess biomass that can not retain
anaerobic condition and can impair the
trickling filter performance.
3. There are high incidences of clogging of
the pores.

31. Trickling Filter Wastewater treatment Plant.

32. summary
- Water pollution is the alteration in the physical, chemical or Biological
characteristics of water so that it either becomes a health hazard or unfit
for use, this is due to the anthropogenic activities which reduce its quality
and composition making it less suitable for drinking domestic use,
industrial use or its ability to support its biotic communities such as fish,
microorganisms, etc..
- Toxic substances from farms, homesteads, municipal sewer lines and
factories readily dissolve into water groundwater and surface water sources
therefore contaminating it.
- Major sources of water pollution are: sewage and wastewater, Industrial
effluents, agricultural activities, mining activities, solid waste material, nuclear
waste and thermal pollution.
- The major effects of water pollutions include; destruction of biodiversity
and ecosystems, eutrophication, reduced DO and increased BOD,
bioaccumulation and biomagnification, spread of diseases and other highly
infectious waterborne disease.

33. Conclusion
Water pollution alters the physical, chemical or
Biological characteristics which reduces its
quality and composition making it unfit for
domestic and industrial usage it is also unable to
support biotic communities. Anthropogenic
activities such as sewage and wastewater,
industrial and mining effluents, power generation
station and solid waste are the most generators of
pollutants of water sources. If this activities can
be checked and regulated the effects of water

34. References
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2. Pradipta K. Mohapatra. 2008. Textbook Of Environmental Microbiology,
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McGraw- Hill Publishing Company Ltd. 918pp
4. Ananth N. 2000. A Textbook Of Microbiology, Vol 4, 1st Edition. Creative
Graphics & Technologies. 279pp
5. Anirban Murkherji, Anirudh Murkherji. 2019. Microbiology, 2nd Edition.
Vinod Kumar Jain, Scientific International (Pvt) Ltd. 407pp.
6. Gabriel Bitton. 1994. Wastewater Microbiology, 4th Edition. John Wiley
& Sons, Inc. Publishers. 578pp.
7. http:// gawater.usgs.gov/edu/wuww.html(beginner’s wastewater
treatment).
8. WWW.iaea.org.at/worldatom-international atomic agency. “World Atom”