Water pollution

1. WATER POLLUTION:-
▪Definition:-It is defined as the contamination of water bodies (e.g.:
lakes , rivers , oceans , and groundwater) . Water pollution occurs
when pollutants are discharged directly or indirectly into water
bodies without adequate treatment to remove harmful compounds.
▪Sources of water pollution:-
• Point source:- due to single , well identified starting place like oil
spill , drain
• Non-point source:-If pollution comes from many sources which
cannot be identified such as acid rain , farmer’s field.
▪Water pollution occurs when pollutants are discharged directly into
water bodies such as rivers , lakes , seas .
▪It also occurs when air and land pollution are blown by wind or
washed by rain into rivers , lakes , and other water bodies.
▪Urban settlements discharge many forms of pollutants into canals,
drains and sewer pipes which eventually find their way into the rivers
and seas. Sources of pollutants include factories, sewage treatment
plants, runoff of chemicals from agricultural plantations and live-
stock farms.
1.Agricultural
Agriculture runoff carrying fertilizers,
pesticides/insecticides/Herbicides and other pollutants into water
bodies such as lakes, rivers, ponds). The usual effect of this type of
pollution consists of algae growing in affected water bodies. This is a
sign of increased nitrates and phosphates in water that could be
harmful to human health.
2.INDUSTRIAL WASTE:
Industrial waste is dumped into nearby freshwater systems. The toxic
chemicals leached from this waste can make the water unsafe

2. for human consumption, and they can also cause the temperature in
freshwater systems to change, making them dangerous for marine
life.
3.SUSPENDED MATERIAL:
Some pollutants do not dissolve in water as their molecules are too
big to mix between the water molecules. This material is called
particulate matter and often be a cause of water pollution.
Ex: plastic, toxic chemicals suspended in water.
4.RADIOACTIVE WASTE:
Dumping of these radioactive wastes in surface waterbodies causes
water pollution. Radioactive contamination is more prevalent in
groundwater as compared to surface water since it is much exposed
to radioactive elements found in the rocks. Sometimes, magma also
releases radioactive gases into the environment.
5.MARINE DUMPING:
Dumping of litter in the sea can cause huge problems.Litter items
with the 6 pack ring packing can get caught in the marine animals
and may result in death. Different items take different lengths of
time to degrade in water.Cardboard-2 weeks,Newspaper-6
weeks,Aluminium-200 years, Plastic-400 years.
6.OIL SPILLAGE:
▪Oceans are polluted by oil on a daily basis from oil spills,routine
shipping, run-offs and dumping
▪Oil spills make up about 12% of the oil that enters the ocean. The
rest come from shipping travel, drains and dumping.

3. 7.Mining:
Water pollution especially groundwater contamination due to mining
is a serious issue as mining operations intersect the water table of
the mined area. Large amounts of suspended solids are common in
groundwater near the mined areas because of ore-washing and
dumps.
8.SEWAGE WASTE:
Improper handling of waste water is the main reason behind the
pollution of water. The careless disposal of sewage water leads to a
chain of problems, such as spreading of diseases, eutrophication,
increase in Biological Oxygen Demand (BOD), etc.
Effects of water pollution;
▪Contaminated drinking water causes cholera, typhoid, poor blood
pressure, vomiting, and damage to nervous system.
▪Pollution in water alter overall chemistry of water, causing a lot of
changes in temperature which adversely effects the marine life and
destroys it.
▪Groundwater contamination from pesticides causes reproductive
damage within wildlife in ecosystem.
▪Water pollution caused flooding due to accumulation of solid waste
and soil erosion in streams and rivers.
▪Water pollution damages food chain.
▪Oil spills in water causes animals to die when they ingest it or
encounter it. Oil doesn’t dissolve in water so it causes suffocation in
fish and birds.
▪Sewage, fertilizer and agriculture runoff contain organic materials
that when discharged into water,increase the growth of algae, which
causes the depletion of oxygen. This is eutrophication.

4. EUTROPHICATION:
▪️Eutrophication, the gradual increase in the concentration of
phosphorus, nitrogen, and other plant nutrients in an aging aquatic
ecosystem such as a lake. The productivity or fertility of such an
ecosystem naturally increases as the amount of organic material that
can be broken down into nutrients increases.
▪This material enters the ecosystem primarily by runoff from land
that carries debris. Water blooms, or great concentrations of algae
and microscopic organisms, often develop on the surface, preventing
the light penetration and oxygen absorption necessary for
underwater life.
GANGA RIVER WATER POLLUTION:-
▪There are 4600 industries in Uttarakhand out of which 298 are
seriously polluting industries. There are many industries which have
not taken permission from the Uttarakhand pollution control board
for their operations, they directly releases their industrial wastes to
the Ganga river.
▪Urban sewage, animal waste, pesticides, fertilizers, industrial metals
and rivulets of ashes from cremated bodies are main cause for Ganga
river pollution.
▪The water was found to be greatly contaminated with a number of
dissolved metals (Fe, Cr, Zn, Cu, Mn, Ni and Pb) whoseconcentrations
were above the safe limits suggested by Bureau of Indian Standard
(BIS 1991) for drinking water.
▪Aside from increased disease from waterborne pathogens and
visible pollution from floating garbage and decomposing corpses,
people using the river also risk developing cancer from toxins.
Cleaning up the Ganges has thus been a priority since the 1980s.

5. STEPS TAKE BY GOVERNMENT TO CONTROL
GANGA RIVER WATER POLLUTION:-
▪“Ganga action plan” is started in 1986.
▪“Namami ganga project” was announced by government in July
2014 budget.
▪Sewage water treatment infrastructure.
▪River surface cleaning.
▪Public awareness.
▪Industrial effluent monitoring.
▪Ganga gram.
EXXON VALDEZ OIL SPILL CASE STUDY
• March 24, 1989 the oil tanker Exxon Valdez ran aground in Prince
William Sound, Alaska, spilling 11 million gallons of oil Tank.
• It had an accident around Alaska's Prince William Sound after
hitting a Bligh Reef.
• This spill resulted in one of the largest environmental disaster in
U.S history.
MARINE POLLUTION IN TELUK BAHANG, MALASIA:-
• Teluk Bahang is a small fishing village located in the north-western
of Penang Island, Malaysia. It has several attractions which include
forest reserved park, ecotourism sites, theme parks and famous for
its aquaculture activities. On 18th April 2019, fish farmers in Teluk
Bahang experienced mass mortality of cultured fishes, due to a
sudden change in water quality. Hence, this study was conducted to
discuss marine pollution that occurred in Teluk Bahang that had
caused the death of tones cultured fishes.

6. ▪Water samples were collected at the fish cages. The results
indicates that metal pollution occurred in teluk bahang. The
concentration of cd , cu and Fe in water levels exceeded 20-100
times and Ni concentration 990 times exceeded from the permissible
limit.
Control Measures
▪ The most effective method to control water pollution is to prevent
or minimize the mixing of pollutants into water bodies.
▪ Water Prevention and Control of Pollution Act, 1972, was enacted
by government of India to control all types of water pollution. It
cares for maintenance and restoration of water of all types, such as
surface water and ground water.
▪ Industries should treat their effluents before they dispose it into
water bodies.
▪ Use only phosphorous and Sulphur free soaps.
▪ Minimize the use of pesticides, herbicides and fertilizers in
agriculture.
▪ Public awareness
▪ Waste water treatment.
Waste water treatment:-The removal of excessively accumulated
matters from the waste water is known as waste water treatment.
Types of Waste water treatment:-
1.Chemical Treatment includes.
a)Primary Treatment.
b) Secondary Treatment and
c) Tertiary Treatment
2. Biological Treatment.

7. Chemical Treatment:-
1.Primary Treatment: It involves screening out of large objects like
cans, rags, sticks. plastic packets etc. carried in the sewage stream.
Suspended matters are allowed to settle in the primary
sedimentation tank. Some chemicals like alum and lime are often
added to Industrial waste for coagulation. The sedimented water is
further led to another joining chamber for secondary treatment.
2.Secondary Treatment: The whole contents are thoroughly aerated
in order to bring down the BOD(bio-chemical oxygen demand) load
from 400ppm to 30ppm and then finally to O ppm.
3. Tertiary Treatment: It involves the treatment of water containing
phosphate and nitrogen. It includes processes like: Coagulation,
Filtration, Membrane separation process. etc.
BIOLOGICAL TREATMENT
▪The principle of biological water treatment methods is on the
degradation of organic compounds present in the effluent by
microorganisms (aerobic and/or anaerobic).
▪The best example is sewage water treatment.
▪Same steps followed as in chemical treatment but here
microorganisms are involved.
Water quality indicator;
Biological oxygen demand (BOD)
BOD refers to the amount of oxygen used for biochemical oxidation
by a unit of volume water at a given temperature and for given time.
Biochemical oxygen demand or biological oxygen demand is the
amount of dissolved oxygen (DO) needed by the micro-organisms in
a particular amount of water at 20 degree Celsius in 5 days.

8. Chemical oxygen demand (COD)
▪️ The quantity of O2 required during chemical oxidation of Om.
▪️ ▪️ ▪️Eutrophication usually results in overgrowth of
phytoplanktons. Once these die, they began to decompose. Their
decomposition causes depletion of dissolved O2, which very
important for fish and other aquatic, this may ultimately lead to
death of fish etc due to suffocation.
▪️ Chemical oxygen demand is the quantity of oxygen required
during chemical oxidation of organic matter.
• Dissolved oxygen (DO):- free oxygen is required by all aerobic
organism for the activity of respiration.
• It is about 8-10 ppm or Mg per litre. The saturation level of
dissolved oxygen (DO) is 14-15 ppm at 0 degreee Celsius in fresh
clear water.
• DO of any water body mainly regulated by its free interchange at
the waters and atmospheric interference, photosynthetic production
of O2 and consumption of O2 by aquatic fauna in their respiratory
activities.
• Dissolved oxygen:- It is free oxygen required by all aerobic
organism for the activity of respiration. It is about 8-10 ppm is
required for reproduction of desired fish.
• Biological oxygen demand:- it is the amount of dissolved oxygen
needed by microbes in a particular amount of water at 20 degree
centigrade in five days.
• Chemical oxygen demand:- It is the quantity of oxygen released
during chemical oxidation of organic matter.
• Water quality indicators

9. Nitrate Poisoning
Nitrate is present in most soils. The three sources are
1.Microbial breakdown soil of organic manures ands plant residues.
2.Fertilizers which had NO3- and that formed by microbial oxidation
of NH+4 (ammonical fertilizer) from or urea
3. Additions from atmosphere
Blue baby syndrome
Excessive use of fertilizers especially N2 lead to accumulating NO3- in
water. When such water is used by man, these NO3- is reduced to
toxic nitrites by intestinal bacteria. No2- causes serious disease in
children called blue baby syndrome / Methemoglobinemia where
NO3-interferes with O2carrying capacity of blood causing
suffocation, damaging respiratory and vesicular system.
Conclusion
▪There are just a few ways that people can help stop water pollution.
These solutions are affordable and reachable. There are also
essential to our future well being.
Submitted by;
Ramya D G : UGS20AGR9925
Ravitheja S R : UGS20AGR9927