Troposphere:

1
(No Transcript)
2

• Troposphere
• composition
• Stratosphere
• benefits of stratospheric ozone production

3
Air pollution sources

• Natural
• Man-made (anthropogenic)
• Stationary
• Mobile

4
Primary Pollutants

• What is the difference between and primary and
  secondary air pollutant? What are NAAQS
  Standards?
• See your handout

CO
CO2
Secondary Pollutants
SO2
NO
NO2
SO3
Most hydrocarbons
HNO3
H2SO4
Most suspended particles
H2O2
O3
PANs
Most
and
salts
Stationary
Natural
Mobile
Sources
5
Types of pollutants

• Primary (1o)
• Secondary (2o)
• Study Table 17-2 condense it into a memorizable
  format!!!

6

• 3. What are the 2 types of smog? Which
  pollutants contribute to smog formation? What
  are the sources of these pollutants? Write the
  chemical equations that show the reactions for
  both types of smog.

7
Photochemical smog

• Reactants and products
• It is a 2o pollutant, forms in urban areas
• N2 O2 2NO
• 2NO O2 2NO2
• NO2 uv NO O (oxygen singlet)
• O2 O O3
• O2 NO ? PANs (peroxyacyl nitrates)
• Does it always stay in urban areas?

8
Sources

• Combustion engines
• N? Is there N in gasoline?
• Unburned HCs in the air?
• Smog Animation

9
Gray-air or industrial smog

• Burning of fossil fuels
• Includes burned and unburned C
• C O2 ?CO2 2C O2 ? 2CO
• S O2 ?SO2 (sulfur dioxide)
• 2SO2 O2 ?2SO3
• SO3 H2O ? H2SO4 (sulfuric acid)
• 2NH3 H2SO4 ? (NH4)2SO4 (ammonium sulfate)

10
What are the major sources of the primary air
pollutants? Health effects?
11
What deadly pollutant is emitted by waste
incineration?

• Dioxin
• Dioxin is formed by burning chlorine-based
  chemical compounds with hydrocarbons. The major
  source of dioxin in the environment comes from
  waste-burning incinerators of various sorts and
  also from backyard burn-barrels. Dioxin pollution
  is also affiliated with paper mills which use
  chlorine bleaching in their process and with the
  production of Polyvinyl Chloride (PVC) plastics
  and with the production of certain chlorinated
  chemicals (like many pesticides).

12
Why is mercury considered an air pollutant?
Source? Forms?

• Like many environmental contaminants, mercury
  undergoes bioaccumulation. Bioaccumulation is the
  process by which organisms (including humans) can
  take up contaminants more rapidly than their
  bodies can eliminate them, thus the amount of
  mercury in their body accumulates over time. If
  for a period of time an organism does not ingest
  mercury, its body burden of mercury will decline.
  If, however, an organism continually ingests
  mercury, its body burden can reach toxic levels.

13
What are different forms of nitrous oxides, or
NOx?
14
Emissions categories for US. Also, which
countries have the worst air quality?
Continents? Cities? Why?

• Research this for extra credit for
  homework!!!!!!!!!!!!!!

15
How do global wind patterns affect air quality?
How about tall smokestacks?

• Transport pollutants around the globe
• Allow pollutants to be emitted above the
  inversion layer, travel elsewhere

16
Temperature inversions
Warmer air
Inversion layer
Cool layer
Mountain
Mountain
Valley
17
Inversion layer
Mountain range
18

• What is acid deposition?
• Which pollutants contribute to the formation of
  acid deposition?
• How does acid deposition travel?
• How does acid deposition affect aquatic
  ecosystems?
• How does acid deposition affect plant life?
• What is the primary source of this pollutant?

19
Acid depositionThe Basic Chemical Reaction

• Sulfur Oxides
• Nitrogen Oxides

SO2 H2O ? H2SO3SO2 1/2O2 ? SO3 H2SO4
NO 1/2O2 ?NO22NO2 H2O ?HNO2 HNO3NO2 OH
? HNO3
20
Why is acid precipitation usually a bigger
problem in the eastern US?
21
(No Transcript)
22
pH values 48 states 1998
23
Potential problem areas because of sensitive soils
Potential problem areas because of air
pollution emissions leading to acid deposition
Current problem areas (including lakes and rivers)
24
Acid Rain Impacts in Europe
25
Solutions
Acid Deposition
Prevention
Cleanup
Reduce air pollution by improving energy
efficiency
Add lime to neutralize acidified lakes
Reduce coal use
Add phosphate fertilizer to neutralize acidified
lakes
Increase natural gas use
Increase use of renewable resources
Burn low-sulfur coal
Remove SO2 particulates, and Nox from
smokestack gases
Remove NOx from motor vehicular exhaust
Tax emissions of SO2
26
List the major indoor air pollutants, their
sources, and their effects on human health.
(Chart!)
27
Para-dichlorobenzene
Tetrachloroethylene
Chloroform
1, 1, 1- Trichloroethane
Formaldehyde
Benzo-a-pyrene
Nitrogen Oxides
Styrene
Tobacco Smoke
Asbestos
Radon-222
Methylene Chloride
Carbon Monoxide
28
Describe the Killer Fog in London and
Pennsylvania. What caused these deadly events?

• http//www.npr.org/templates/story/story.php?story
  Id873954
• http//www.ccohs.ca/oshanswers/chemicals/chem_prof
  iles/sulfurdi/health_sul.html
• http//www.atsdr.cdc.gov/toxprofiles/tp116.htmlbo
  okmark03

29
Solutions
Stationery Source Air Pollution
Dispersion or Cleanup
Prevention
Burn low-sulfur coal
Disperse emissions above thermal inversion layer
with tall smokestacks
Remove sulfur from coal
Convert coal to a liquid or gaseous fuel
Remove pollutants after combustion
Shift to less polluting fuels
Tax each unit of pollution produced
30
Describe how the following air pollution
reduction devices work and on which pollutants

• Cyclone separator
• Electrostatic precipitator
• Baghouse filter
• Wet scrubber

31
Electrostatic Precipitator
32
Cleaned gas
Dirty gas
Baghouse Filter
Dust discharge
33
Dirty gas
Cyclone Separator
Dust discharge
34
Dirty gas
Clean water
Dirty water
Wet Scrubber
35
Problem of the day

• The flow rate from a tailpipe is 3.5 mph, and the
  radius is 5 cm. What is this in m/s? If the car
  is usually driven for 2 h/d, what is the volume
  of exhaust released each day? The conc of CO2 is
  7. What is the volume of CO2 released per day?

36
Acid deposition

• Sources
• Rxns
• Impacts on terrestrial and aquatic systems
• What is done about it