Environmental engineering - air pollution

1. ENVIRONMENTAL
ENGINEERING
AIR POLLUTION
By: John Paul Espino
De La Salle University – Dasmarinas
Facebook.com/Johnpaul.dss

3. Key Concepts
Structure and composition of the atmosphere
Types and origins of major outdoor air pollutants
Two types of smog
Acid deposition and how it can be reduced
Harmful effects of air pollutants
Preventing and controlling air pollution

4. When is a Lichen Like a Canary?
 Mine canaries
 Lichens
 Detectors of air pollution
 Isle Royale in Lake Superior
 Chernobyl
Fig. 15-1, p. 345

5. When is a Lichen Like a Canary?
Fig. 15-1, p. 345

6. Lichens
Symbiotic organisms
- Dominant partner is a fungus.
The lichen fungi cultivate
partners that photosynthesize.
Sometimes the partners are
algae (K. Protista), other times
cyanobacteria (K. Monera).
Some enterprising fungi use both
at once! 
- Lichens are important in soil
formation & serve as indicators
of air quality
- (soil formation animation)

8. Earth’s
Atmosphere
Troposphere
78% N2, 21% O2
Stratosphere
Ozone layer
Fig. 15-2, p. 347

9. Fig. 15-2, p. 347
Earth’s
Atmosphere
Atmospheric pressure (millibars)
0 200 400 600 800 1,000
120
110
100
90
80
70
60
50
40
30
20
10
0
(Sea Level)
–80 –40 0 40 80 120 Pressure = 1,000
millibars at
ground levelTemperature (˚C)
Altitude(kilometers)
Altitude(miles)
75
65
55
45
35
25
15
5
Thermosphere
Heating via
ozone
Mesosphere
Stratosphere
Ozone “layer”
Heating from the
earth
Troposphere
Temperature
Pressure
Mesopause
Stratopause
Tropopause

10. Outdoor Air
Pollution What is air pollution?
 Stationary and mobile sources
 Primary pollutants
 Secondary pollutants
 How air pollutants migrate
 Health threats
 Major air pollutants
 Volatile organic compounds (VOCs)
 Carbon dioxide: a pollutant?

11. Primary Pollutants
Secondary Pollutants
Sources Natural
Stationary
CO CO2
SO2 NO NO2
Most hydrocarbons
Most suspended
particles
SO3
HNO3 H2SO4
H2O2 O3 PANs
Most and saltsNO3
–
Mobile
SO4
2–
Fig. 15-3, p. 348
Sources and Types of Air Pollutants

12. Table 15-1, p. 349

13. Photochemical
Smog
Photochemical reactions
Photochemical smog
Natural and human origins
Brown-air smog
Temperature effects
Urban areas

14. Formation of photochemical smog
Animation

15. Photochemical
Smog in Mexico
City
Fig. 15-4, p. 351

16. Industrial
Smog
 Composition of industrial smog (sulfur dioxide and sulfuric acid)
 Gray-air smog
 Situation better in developed countries
 Serious problem in industrializing countries, such as China
 “BlackTriangle” of eastern Europe
 Asian brown cloud

17. Industrial Smog in India
Fig. 15-5, p. 351

18. How Nature
Eliminates
Smog
Rain and snow
Salty sea spray
Winds

19. Factors
Influencing the
Formation
of Smog Urban buildings
 Topography
 High temperatures
 “Grasshopper Effect” – occurs when volatile air pollutants are
transported from tropical and temperate areas toward the earth’s
poles, especially during winter; explains why polar bears, whales,
sharks, top carnivores and native peoples in the arctic have high
levels of DDT and other long-lived pesticides, toxic metals (Pb &
Hg) even in the absence of industrial facilities and cars
 Temperature inversions

20. Thermal inversion animation.
Animation

21. Acid
Deposition Sulfur dioxide and nitrogen oxides
 Wet and dry acid deposition
 Acid rain – pH below 5.6
 Regional air pollution
 OhioValley
 Buffers
 Wind transportation

22. Fig. 15-6, p. 353
Wind
Transformation to
sulfuric acid (H2SO4)
and nitric acid (HNO3)
Nitric oxide (NO)
Acid fog
Ocean
Sulfur dioxide (SO2)
and NO
Windborne ammonia gas
and particles of cultivated soil
partially neutralize acids and
form dry sulfate and nitrate salts
Dry acid
deposition
(sulfur dioxide
gas and particles
of sulfate and
nitrate salts)
Farm
Lakes in
deep soil
high in limestone
are buffered
Lakes in shallow
soil low in
limestone
become
acidic
Wet acid deposition
(droplets of H2SO4 and
HNO3 dissolved in rain
and snow)
Acid Deposition

23. Animation
Acid deposition animation.

24. 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)
Fig. 15-8, p. 355
Current and Potential Problems with
Acid Deposition

25. Harmful Effects
of Acid
Deposition
 Respiratory diseases in humans (bronchitis and asthma)
 Leaches metals from water pipes
 Damages statues and other property
 Decreases atmospheric visibility (Grand Canyon)
 Kills fish and other aquatic organisms
 Leaches plant nutrients from soils
 Weakens trees (mountaintop forests)

26. Emission
Acid
deposition
SO2
H2O2
PANs
NOX
O3
Others
Direct damage
to leaves and bark
Reduced
photosynthesis
and growth
Increased
Susceptibility
to drought,
extreme cold,
insects, mosses,
and disease
organisms
Soil acidification
Leaching
of soil
nutrients
Acid
Release
of toxic
metal
icons
Root
damage
Reduced nutrient
and water uptake
Tree death
Groundwater
Fig. 15-9, p. 356
Impacts of Air Pollution
on Trees and Water

27. Animation
Effect of air pollution in forests animation.

28. Tree Damage
from Acid
Deposition
Fig. 15-10, p. 356

29. © 2006 Brooks/Cole - Thomson
Reduce air pollution by
improving energy efficiency
Reduce coal use
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
Add lime to neutralize
acidified lakes
Add phosphate
fertilizer to neutralize
acidified lakes
Solutions
Acid Deposition
Prevention Cleanup
Fig. 15-11, p. 357
Reducing Acid Deposition

30. Indoor Air
Pollution
 Pollutants often at higher concentrations indoors
 Pollution inside cars
 Most people spent most of their time indoors
 Cancer risks
 Sick-building syndrome
 Mold and allergies
 Serious problem in developing countries

31. Major
Indoor Air
Pollutants
Tobacco smoke
Formaldehyde
Radon
Very fine particles

32. Fig. 15-12, p. 358
Chloroform
Benzo-a-pyrene
Styrene
Radon-222
Methylene Chloride
Tobacco
Smoke
Carbon Monoxide
Asbestos
Nitrogen
Oxides
1, 1, 1-
Trichloroethane
Major Indoor Air Pollutants
Particulates
FormaldehydeTetrachloro-ethylene
Para-dichlorobenzene

33. Radon
 Radioactive Rn-222
 Lung cancer threat
 With uranium in rocks
and soils
 Testing homes
 Remedies
Fig. 15-13, p. 359

34. Fig. 15-13, p. 359
Outlet vents for furnaces and dryers
Slab joints
Wood stove
Cracks in floor
Clothes
dryerFurnace
Radon-222 gas
Slab
Soil
Uranium-238
Sump
pump
Cracks in wallCracks in wall
Open windowOpen window
Openings
around
pipes
Openings
around
pipes
Radon

35. Harmful
Effects of Air
Pollution
 Human respiratory system
 Asthma
 Lung cancer
 Chronic bronchitis
 Emphysema
 Health effects of major air pollutants (Table 15-1, p. 349)
 Premature deaths
 Serious threat of indoor air pollution
 Impact of coal-fired power plants
 Cancer from diesel exhausts

36. Fig. 15-14a, p. 360
Human Respiratory System

37. Fig. 15-14a, p. 360
Nasal cavity
Oral cavity
Pharynx (throat)
Trachea (windpipe)
Bronchus
Right lung
Bronchioles
Human Respiratory System

38. Fig. 15-14b, p. 360
Epithelial
cell
Cilia
Mucus
Human Respiratory System
Goblet cell
(secreting
mucus)

39. Fig. 15-14c, p. 360
Bronchiole
Alveolar
duct
Alveoli
Alveolar sac
(sectioned)
Human Respiratory System

40. Healthy and
Diseased Human
Lungs
Fig. 15-15, p. 360

41. © 2006 Brooks/Cole - Thomson
Solutions
Stationery Source Air Pollution
Prevention Dispersion or
Cleanup
Burn low-sulfur
coal
Remove sulfur
from coal
Convert coal
to a liquid or
gaseous fuel
Shift to less
polluting fuels
Disperse
emissions above
thermal inversion
layer with tall
smokestacks
Remove
pollutants after
combustion
Tax each unit
of pollution
produced
Fig. 15-17, p. 363
Solutions: Stationary Source Air
Pollution

42. © 2006 Brooks/Cole - Thomson
Solutions
Motor Vehicle Pollutions
Prevention Cleanup
Mass transit
Bicycles and walking
Less polluting engines
Less polluting fuels
Improve fuel efficiency
Get older, polluting
cars off the road
Give buyers tax write-
offs for buying low-
polluting, energy-
efficient vehicles
Restrict driving in polluted areas
Emission control
devices
Car exhaust
Inspections
twice a year
Stricter emission
standards
Fig. 15-18, p. 364
Solutions: Motor Vehicles

43. © 2006 Brooks/Cole - Thomson
Solutions
Indoor Air Pollution
Prevention Cleanup
Cover ceiling tiles and lining
of AC ducts to prevent release
of mineral fibers
Ban smoking or limit it to
well-ventilated areas
Set stricter formaldehyde
emissions standards for
carpet, furniture, and
building materials
Prevent radon infiltration
Use office machines in
well-ventilated areas
Use less polluting
substitutes for harmful
cleaning agents, paints,
and other products
Use adjustable fresh air vents
for work spaces
Increase intake of outside air
Change air more frequently
Circulate building’s air through
rooftop greenhouses
Use exhaust hoods for stoves
and appliances burning
natural gas
Install efficient chimneys
for wood-burning stoves
Fig. 15-19, p. 364
Solutions: Indoor Air Pollution

44. Solutions
Air Pollution
Prevention Cleanup
Improve energy efficiency
to reduce fossil fuel use
Rely more on lower-
polluting natural gas
Rely more on renewable
energy (especially solar
cells, wind, and solar-
produced hydrogen)
Transfer technologies for
latest energy efficiency,
renewable energy, and
pollution prevention to
developing countries.
Reduce poverty
Distribute cheap and efficient
cookstoves to poor families in
developing countries
Reduce or ban indoor smoking
Develop simple and cheap
test for indoor pollutants
such as particulates, radon,
and formaldehyde
Fig. 15-20, p. 365
Solutions: Air Pollution