it's about ozone layers --environmental engineering

1. EGEE 102 – Energy Conservation
And Environmental Protection
Ozone and Environment

2. EGEE 102 - Pisupati 2

3. EGEE 102 - Pisupati 3
Ozone
• O3
• a gas composed of three atoms of
oxygen
• bluish gas that is harmful to breathe
• Nearly 90% of the Earth's ozone is in
the stratosphere and is referred to as
the ozone layer
• Ozone absorbs a band of ultraviolet
radiation called UVB

4. EGEE 102 - Pisupati 4

5. EGEE 102 - Pisupati 5

6. EGEE 102 - Pisupati 6
Ozone-Depleting
Substance(s) (ODS):
• CFCs,
• HCFCs,
• halons,
• methyl bromide,
• carbon tetrachloride, and
• methyl chloroform.

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Various sources

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Effects of OLD
• -- Skin Cancer (melanoma and
nonmelanoma)
-- Premature aging of the skin and other
skin problems
-- Cataracts and other eye damage
-- Immune system suppression

9. EGEE 102 - Pisupati 9
The Antarctic Ozone
Hole
• The ozone hole is
defined as the area
having less than 220
dobson units (DU) of
ozone in the
overhead column
(i.e., between the
ground and space).
Source: http://jwocky.gsfc.nasa.gov/multi/recent_ozone91200.gif

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http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/ozone_hole_plot.gif

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Actions
• http://www.epa.gov/ozone/title6/phaseo
ut/22phaseout.html

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What can we do?
• Make sure that technicians working on your
car air conditioner, home air conditioner, or
refrigerator are certified by an EPA approved
program to recover the refrigerant (this is
required by law).
• Have your car and home air conditioner units
and refrigerator checked for leaks. When
possible, repair leaky air conditioning units
before refilling them.

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What can we do?
• Contact local authorities to properly dispose
of refrigeration or air conditioning equipment.
• Protect yourself against sunburn. Minimize
sun exposure during midday hours (10 am to
4 pm). Wear sunglasses, a hat with a wide
brim, and protective clothing with a tight
weave. Use a broad spectrum sunscreen with
a sun protection factor (SPF) of at least 15
and 30 is better.

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Ground level Ozone
Formation
• Secondary Pollutant
• VOCs+ NOx  Ozone
• In presence of sunlight
• Ozone + NOX + HCs  Smog (haze)

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Photochemical Smog
NO
CO, RH
NO2
CO
HC
O3
CO
PAN
Haze
6:00AM 12NOON 3:00 PM

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Smog Sources
Source: http://www.epa.gov/oar/oaqps/regusmog/smog.html

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Sources of Volatile
Organic Carbons

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Sources of NOx

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What can We do?
• Keep your automobile well tuned and
maintained.
• Carpool, use mass transit, walk, bicycle,
and/or reduce driving, especially on hot
summer days.
• Be careful not to spill gasoline when filling up
your car or gasoline-powered lawn and
garden equipment. During the summer, fill
your gas tank during the cooler evening
hours.

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What can we do?
• Make sure your car's tires are properly
inflated and your wheels are aligned.
• Participate in your local utility's energy
conservation programs.
• Seal containers of household cleaners,
workshop chemicals and solvents, and
garden chemicals to prevent VOC from
evaporating into the air. Dispose of them
properly.