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1. A SEMINAR ON:
ADVERSE EFFECT OF OXYGEN DEMANDING
WASTE
SUBMITTED BY:
Chhoto Kisku
AEM-327

2. INTRODUCTION
Any material which cannot be used in the form in
which it is produced is called a Waste.
 It is no longer needed by us because it has lost its
value. If it is thrown around, it can cause soil, air or
water pollution. It also poses a serious threat to
normal life, plants, animals and human beings.

3. Definition….
The amount of oxygen absorbed by a sample of sewage
during a specific period, generally 5 days at a specific
temperature, generally 20° C for the aerobic destruction
of the organic matter by living organisms.
Total BOD is of more significance to food webs than
to water quality.
Oil spill:
An oil spill is the release of a liquid
petroleum hydrocarbons into the
environment due to human activity. And it is
a form of pollution

4. Cont….
Nitrates and phosphates in a body of water can
contribute to high BOD levels.
Nitrates and phosphates are plant nutrients and can
cause plant life and algae to grow quickly.
When plants grow quickly, they also die quickly.
This contributes to the organic waste in the water, which
is then decomposed by bacteria resulting in a high BOD
level.

5. Environmental significance
Principle test for biodegradability of any sample and strength of
the waste so measures the amount of pollution.
Important parameter to assess the pollution of surface and ground
waters where contamination occurred due to disposal of domestic
and industrial effluents.
Allows calculation of the effect of the discharges on the oxygen
resources of the receiving water.
Measurement of BOD in raw (influent) and treated (effluent)
wastewaters is a standard practice to evaluate treatment facility
performance.
Data from BOD tests used for the development of engineering
criteria for the design of wastewater treatment plants.

6. Cont….
Used in studies to measure the self-purification capacity of
streams
Serves regulatory authorities as a means of checking on the
quality of effluents discharged to stream waters.
One of the most important method in sanitary analysis to
determine the polluting power, or strength of sewage, industrial
wastes or polluted water.
It serves as a measure of the amount of clean diluting water
required for the successful disposal of sewage by dilution.

7. Factors affecting BOD…
Temperature
Elevated temperature decreases the level of DO of water
harming aquatic organisms like fish, amphibians and others
Increases the metabolic rate of aquatic animals and
enzyme activity, resulting in consumption of more food in a
shorter time
High temperature limits oxygen dispersion into deeper waters,
contributing to anaerobic conditions.
This can lead to increased bacterial levels when there is
ample food supply.
Higher water temperature increases plant growth rates
This results in a shorter lifespan and species overpopulation
causing an ”algae bloom” which reduces oxygen levels.

8. Eutrophication

9. Eutrophication occurs due to oversupply of nutrients, which
causes explosive growth of plants and algae.
when such organisms die, consume the oxygen in the body of
water, thereby creating the state of hypoxia.
The primary limiting factor is phosphorus which promotes
excessive plant growth and decay, favouring simple algae and
plankton, and causes a severe reduction in water quality.
Phosphate adheres tightly to soil, so it is mainly transported by
erosion.
Once into the lakes, phosphate is extracted into water is slow,
hence the difficulty of reversing the effects of eutrophication
The source of this excess phosphate are detergents,
industrial/domestic run-off, and fertilizers.
CONT……

10. At higher levels of BOD….At high BOD levels, organisms such as macro
invertebrates that are more tolerant of lower dissolved
oxygen (i.e. leeches and sludge worms) may appear and
become numerous.
Organisms needing higher oxygen levels (i.e. caddisfly
larvae and mayfly nymphs) will NOT survive.

11. It is produced when oxygen dissolved in water reacts
with pyritic materials found in association with most
coal deposits. AMD degrades the water quality of
stream and supplies often to the point of eliminating all
biological activity within the stream contaminated with
AMD.

12. Physical effects of oil in water:
Reduction in dissolved oxygen – oil films are
able to retard significantly the rate of oxygen
uptake by water.
Reduction in light penetration – oil slick
decreases the light intensity up to 90%
Smothering – Smothering coats of oil have
killed lichens and algae along the shore line.

13. Garbage waste need oxygen for
decomposing
It is very harmful to our environment because
of the way it is currently being disposed
It possess dangerous risk to our land, water
and air
Landfill disposal if leaked, will contaminate
surface and ground water which in turn will
travel to the nearest ocean or lake and poison
the wildlife there.
Incinerating trash has bad effect on the
environment as it contributes to air pollution
which causes global warming.

14. Conclusion:
Disposing of waste has
huge environmental impacts and can
cause serious problems. ... Some waste will
eventually rot, but not all, and in the
process it may smell or generate methane
gas, which is explosive and contributes to
the greenhouse effect. Leachate produced
as waste decomposes may cause pollution.

15. Thankyou