Es air pollutions 1. Air Pollutions 2. Presentation outline • Introduction • Structure of Atmosphere • Definition of Air Pollution • Source of Air Pollution • Classification of Air Pollution • Effect of Air Pollution • Control of Air Pollution

1. Air Pollutions

2. Presentation outline
• Introduction
• Structure of Atmosphere
• Definition of Air Pollution
• Source of Air Pollution
• Classification of Air Pollution
• Effect of Air Pollution
• Control of Air Pollution

3. What does the atmosphere do for us?
• Obviously everyone has to breathe. We need
oxygen to keep our bodies working. Just try
holding your breath for a few seconds and see
what happens. People are not the only ones
who need oxygen; all kinds of animals need it
too. Without the atmosphere we would all
quickly die. But that's not the only thing the
atmosphere does for us.

4. Benefits of Atmosphere
• A RADIATION SHIELD
• SECURITY BLANKET
• WEATHERING THE STORMS

5. Atmosphere as a Resource
• Atmospheric
Composition
– Nitrogen 78.08%
– Oxygen 20.95%
– Argon 0.93%
– Carbon dioxide 0.04%

6. Structure of Atmosphere
• The Atmosphere is divided into layers
according to major changes in temperature.
Gravity pushes the layers of air down on the
earth's surface
• 99% of the total mass of the atmosphere is
below 32 kilometres.

7. Structure of Atmosphere
Name of part Height From Earth surface
in km
Temperature in c
Troposphere 00-11 15 to (-55)
Stratosphere 11-50 (-2) to (-55)
Mesosphere 50-85 (-2) to (-90)
Thermosphere 85-100 (-90) to (-1200)

8. Layer of Atmosphere

9. Air Pollution
• Chemicals added to the atmosphere by
natural events or human activities in high
enough concentrations to be harmful that’s
call Air Pollution .
• Possibly one of the most important
characteristics of air pollutants is their trans-
boundary nature - they can easily travel and
affect the areas far away from their points of
origination.

10. Source of Air pollution
Natural pollution
• volcanoes, fumaroles
and hot springs
• decay from marshes,
bogs
• increase ozone due to
thunder storms, fires.
Man made pollution
• Stationary sources -
those that are fixed in
location.
• Mobile sources - those
that move while
polluting, e.g. trucks,
cars, busses etc

11. Classification of air pollution
• Classification based on origin of air pollution
• Gaseous Air Pollutants
• Air borne Particules as Air Polluants

12. Classification based on origin of air
pollution
• Primary air pollutants are the ones that are
emitted directly into the atmosphere by the
sources (such as power-generating plants).
• Secondary air pollutants are the ones that are
formed as a result of reactions between
primary pollutants and other elements in the
atmosphere, such as ozone.

13. Gaseous Air Pollution
• There pollutions are in gaseous state at
normal temperature and pressure.
• Common gas pollutants are
– COX
– SOX
– Nox
–O3

14. SO2 Sulphur Dioxide
• Colourless gas with penetrating and pungent odour
• produced mainly when coal and fuel oil are burned
• present in power plant exhaust
• narrows the airway, causing sneezing and shortness of
breath, especially in those with asthma
S + O2  SO2
2 SO2 + O2  2SO3
SO3 + H2O  H2SO4

15. CO-Carbon Monoxide
• colorless, odorless, tasteless, non irritating
gas
• produced when carbon does not burn in fossil
fuels, ie incomplete combustion.
• Commonly present in automobile exhaust
• CO is very dangerous asphyxiant and its high
levels are fatal to human life.

16. NOx-Nitrogen Dioxide
• reddish, brown gas
• produced when nitric oxide combines with
oxygen in the atmosphere
• present in car exhaust and power plants
N2 + 2O2  2NO2
4NO2+2H2O+O2  4HNO3

17. HYDROCARBONS
• Hydrocarbons are compounds that have carbon
and hydrogen
• Benzene, methane, etc are common
hydrocarbon pollutants.
• The major sources are automobile and industrial
exhaust..
• Benzene: colorless, flammable liquid pollutant
have carcinogenic property…
• Methane is common green house gas .. It
produce by naturally along with human activities.

18. Air borne Particules as Air Pollution
• Solid particles between 1 and 100 μm
(micrometres) in diameter are
called dust particles, while solid particles less
than 1 μm in diameter are called fumes,
or smoke.

19. Effect of air Pollution
• Health of Human and other Animals
• Greenhouse effect
• Acid Rain
• Ozone Departing

20. Health of Human and other Animals
• People facing problem like skin cancer ,
problem in eye(to watch) etc.
• Children who live in high ozone areas are
more likely to develop asthma.

21. Greenhouse effect
• Carbon dioxide and other gases allow light to
pass , but trap heat in the atmosphere much
like glass in greenhouse traps heat.
• This greenhouse effect is thought to be
responsible for global warming.
• Global warming is increase in the average
temperature of the atmosphere

22. Greenhouse effect

23. Impact of Global warming
• Temperature extremes
• Rise in sea level
• Injuries from storms, coastal flooding
• Interruption of power supply, contamination
of drinking water
• Drought
• Food shortages due to shift in agricultural
food production

24. Impact of Global warming
• Air pollution ( made worse by warming)
• Asthma, bronchitis, emphysema
complications
• Strain on public health systems
• Increased need due to population
migrations
• Unable to contain spread of infectious
diseases

25. Acid Rain
• The term "acid rain" is commonly used to
mean the deposition of acidic components in
rain

26. Acid Rain
• its pH being about 5.6, because carbon
dioxide and water in the air react together to
form carbonic acid, a weak acid.
• H2O + CO2 → H2CO3(aq)
• The main sources of these pollutants are
vehicles and industrial and power-generating
plants.

27. Acid rain reaction
• SO2 + water vapor + ozone H2SO4
• NO + sunlight + O2 NO2 + various
• atmospheric gases  HNO3

28. Acid rain - causes
• The principal cause of acid rain is sulfur- and
nitrogen compounds from human sources,
such as electricity generation, factories and
motor vehicles. Coal power plants are one of
the most polluting.

29. Process

30. Effects of Acid Rain
• Acidify lakes
• leaches metals out of rocks and soil
• kill fish, plants

31. Ozone depletion
• The stratosphere
contains the ozone
shield, a layer of ozone
(O3) in the
stratosphere, 50 km
above the ground.

32. Hazards of UV radiation
• Hazards of UV radiation include increased
mutation rate, which can lead to skin cancer
and cataracts, depression of the immune
system, impaired crop and tree growth, and
the death of plankton.

33. Health effects of Ozone depletion
• By the UV radiation, 75
million cases of
cataracts and 300,000
more cases of skin
cancer every year.

34. Ozone Hole above Antarctica
• During the 1980s scientists discovered a
"hole" in the ozone over Antarctica.
• By the 1990s atmospheric scientists had
detected an annual loss of 40-50% of the
ozone above Antarctica, which produced an
ozone hole every spring.
• One CFC molecule can destroy 100,000 ozone
molecules.

35. Control of Air Pollutants
Methods of air pollution control can be divided
into two categories:
•THE CONTROL OF PARTICULATE EMISSIONS
•THE CONTROL OF GASEOUS EMISSIONS

36. THE CONTROL OF PARTICULATE
EMISSIONS
• The term particulate refers to tiny particles of
matter such as smoke, soot, and dust that are
released during industrial, agricultural, or
other activities.
• Particulate matter can be control by using
following devices

37. Gravitational Settling Chamber
• Like settling basins in
water and waste water
treatment, settling
chambers provide
enlarged areas to
minimize horizontal
velocities of air flow
thus allow time
for gravity to carry the
particle to the floor.

38. Filtration
• Filters consist of porous
structure composed of granular
or fibrous material which tends
to retain the particulate matter
as the carrier gas passes through
the voids of the filter.
• The dust is collected on the
inside of the bag surface and the
filtered gas is discharged to the
atmosphere
• 99% efficient

39. Wet Scrubbers
• spray systems where
fine water droplets are
sprayed at high velocity
at right angles to the
emerging gas
• relatively low
efficiencies (80-90%)
and is usually employed
as a pre-cleaner to
remove particles larger
than 5m

40. General solutions:
• switch from coal to cleaner fuels - use natural
gas
• reduce energy use, improve energy efficiency
• burn less coal, use lower sulfur coals. Coal
gasification
• After burning the SO2 can be cleaned out by
scrubbing
• Give education about control of air pollution.

41. Bibliography
• Google
• Wikipedia
• Tropical-Rainforest-Animals.com
• ScienceTerrific.com
• Environmental Studies By Snehal Popli

42. THANK YOU