Air and Air Pollution Brian Kaestner Saint Mary’s Hall Thanks to Miller and Clements
Dec 28, 2015
Air and Air PollutionAir and Air Pollution
Brian Kaestner
Saint Mary’s Hall
Brian Kaestner
Saint Mary’s Hall
Thanks to Miller and ClementsThanks to Miller and Clements
Key ConceptsKey Concepts
Structure and composition of the atmosphere Structure and composition of the atmosphere
Types and sources of outdoor air pollution Types and sources of outdoor air pollution
Types, formation, and effects of smog Types, formation, and effects of smog
Sources and effects of acid deposition Sources and effects of acid deposition
Effects of air pollution Effects of air pollution
Prevention and control of air pollution Prevention and control of air pollution
The AtmosphereThe Atmosphere
Troposphere Troposphere
Stratosphere Stratosphere
78% N, 21% O 78% N, 21% O
Ozone layer Ozone layer
Greenhouse effect Greenhouse effectPressure = 1,000Pressure = 1,000millibars atmillibars atground levelground level
Atmospheric pressure (millibars)Atmospheric pressure (millibars)
00 200200 400400 600600 800800 1,0001,000120120
110110
100100
9090
8080
7070
6060
5050
4040
3030
2020
1010
00(Sea(Sea
Level)Level)
––8080 ––4040 00 4040 8080 120120Temperature (˚C)Temperature (˚C)
Alt
itu
de
(k
ilo
me
ters
)A
ltit
ud
e (
kil
om
ete
rs)
Alt
itu
de
(m
ile
s)
Alt
itu
de
(m
ile
s)
7575
6565
5555
4545
3535
2525
1515
55
ThermosphereThermosphere
Heating via ozoneHeating via ozone
MesosphereMesosphere
StratosphereStratosphere
Ozone “layer”
Heating from the earthTroposphere
TemperatureTemperature
PressurePressure
MesopauseMesopause
StratopauseStratopause
Tropopause
Fig. 17.2, p. 418
Outdoor Air PollutionOutdoor Air Pollution
Primary pollutants Primary pollutants Secondary pollutants Secondary pollutants
Primary Pollutants
Secondary Pollutants
SourcesNatural Stationary
CO CO2
SO2 NO NO2
Most hydrocarbons
Most suspendedparticles
SO3
HNO3 H2SO4
H2O2 O3 PANs
Most and saltsNO3–
Mobile
SO42–
Fig. 17.4, p. 422See Table 17-1 p. 421See Table 17-2 p. 422
Nitric oxide Nitrogen dioxide Ozone40
30
20
10
06 7 8 9 10 11 12 1 2 3 4 5 6 7 8
A.M. Noon P.M.Time
Par
ts p
er m
illi
on
Fig. 17.6, p. 424
Photochemical SmogPhotochemical Smog
Brown-air smog Brown-air smog
Photochemicalreaction
Photochemicalreaction
Photochemicaloxidants
Photochemicaloxidants
Solarradiation
Ultraviolet radiation
NONitric oxide
Photochemical smog
H2OWater
NO2
Nitrogendioxide
Hydrocarbons
O2
Molecularoxygen
HNO3
Nitric acid
PANsPeroxyacyl
nitratesAldehydes
(e.g., formaldehyde)
O3
Ozone
OAtomicoxygen
Fig. 17.5, p. 424
Industrial SmogIndustrial Smog
Gray-air smogGray-air smog
Industrial smogIndustrial smog
Sulfuric acidSulfuric acid
Sulfur dioxideSulfur dioxide
ParticulatesParticulates
Ultra FineUltra FineParticlesParticles
FineFineParticlesParticles
LargeLargeParticlesParticles
Sea salt nuclei
Carbon black
Pollens
Cement dust
Oil smoke
Combustion nuclei
Metallurgical dust and fumes
Photochemical smog
Insecticide dusts
Coal dust
Average particle diameter (micrometers or microns)Average particle diameter (micrometers or microns)0.0010.001 0.010.01 2.52.5 10.010.0 100.0100.0
Tobacco smoke
Paint pigments
Fly ash
Milled flour
Fig. 17.7, p. 425
LA - 1956
Temperature InversionsTemperature Inversions
Subsidence inversionSubsidence inversion
Radiation inversionRadiation inversionWarmer airWarmer air
Inversion layerInversion layer
Cool layer
MountainMountainMountain
ValleyValley
Decreasing temperatureDecreasing temperature
Incr
easi
ng
alt
itu
de
Incr
easi
ng
alt
itu
de
Fig. 17.8, p. 426
Inversion layer
Mountainrange
Sea breeze
Descending warm air mass
Decreasing temperature
Incr
easi
ng
alt
itu
de
Fig. 17.8b, p. 426
Regional Outdoor Air Pollution from Acid DepositionRegional Outdoor Air Pollution from Acid Deposition
Acid depositionAcid depositionWet depositionWet deposition Dry depositionDry deposition
Wind
Transformation tosulfuric acid (H2SO4)and nitric acid (HNO3)
Nitric oxide (NO)
Acid fog
Ocean
Sulfur dioxide (SO2)and NO
Windborne ammonia gasand particles of cultivated soilpartially neutralize acids andform dry sulfate and nitrate salts
Dry aciddeposition(sulfur dioxidegas and particlesof sulfate andnitrate salts)
Farm
Lakes indeep soilhigh in limestoneare buffered
Lakes in shallowsoil low inlimestonebecomeacidic
Wet acid deposition(droplets of H2SO4 andHNO3 dissolved in rainand snow)
Fig. 17.9, p. 428
Acid Deposition in the USAcid Deposition in the US
Fig. 17.10, p. 428
Potential problem areasbecause of sensitive soils
Potential problem areas because of air pollution: emissions leading to acid deposition
Current problem areas(including lakes and rivers) Fig. 17.11, p. 429
Acid Deposition and HumansAcid Deposition and Humans
Respiratory diseases Respiratory diseases
Toxic metal leaching Toxic metal leaching
Decreased visibility Decreased visibility
Damage to structures, especially containing limestone
Damage to structures, especially containing limestone
Decreased productivity and profitability of fisheries, forests, and farms
Decreased productivity and profitability of fisheries, forests, and farms
Acid Deposition and Aquatic SystemsAcid Deposition and Aquatic Systems
Fish declines Fish declines
Undesirable species
Undesirable species
Aluminum toxicity
Aluminum toxicity
Acid shock Acid shock
WaterWaterboatmanboatman
WhirligigWhirligig
Yellow perchYellow perch
Lake troutLake trout
Brown troutBrown trout
SalamanderSalamander(embryonic)(embryonic)
MayflyMayfly
SmallmouthSmallmouthbassbass
MusselMussel
6.56.5 6.06.0 5.55.5 5.05.0 4.54.5 4.04.0 3.53.5pHpH
Fig. 17.13, p. 430
Acid Deposition, Plants, and SoilAcid Deposition, Plants, and Soil
Nutrient leaching
Nutrient leaching
Heavy metal release
Heavy metal release
Weakens trees Weakens trees
Emissions
Effects of Weather
Aciddeposition
Dryweather
Lowprecipitation
Increasedevapotranspiration
Increasedtranspiration
LakeGroundwater
SO2 NOX
H2O2 O3
PANs Others
Increasedsusceptibility
to frost,pests, fungi,
mosses,and disease
Dead leavesor needles
Reducedphotosynthesis
and growth
Tree deathDamageto treecrown
Waterdeficit
Nutrientdeficiency
Bark damage
Direct damageto leaves
and needles
Leaching ofsoil nutrients
Acidsand soilnutrients
Damage tofine roots Disturbance
of wateruptake
Disturbanceof nutrient
uptake
Soil acidification
Kills certainessential soil
microorganisms
Release of toxic metal ionsN
itra
te
Su
lfat
e
Mag
nes
ium
Alu
min
um
Cal
ciu
m
Po
tass
ium
Aci
ds
Fig. 17.14, p. 432See Connections p. 431
Solutions: Preventing and Reducing Air PollutionSolutions: Preventing and Reducing Air Pollution
Clean Air ActClean Air Act
National Ambient Air Quality Standards (NAAQS)
National Ambient Air Quality Standards (NAAQS)
Primary and secondary standardsPrimary and secondary standards
Output control vs. input controlOutput control vs. input control
Emission ReductionEmission Reduction
Prevention Dispersionor Cleanup
Burn low-sulfurcoal
Remove sulfurfrom coal
Convert coalto a liquid orgaseous fuel
Shift to lesspolluting fuels
Disperseemissions abovethermal inversionlayer with tallsmokestacks
Removepollutants aftercombustion
Tax each unitof pollutionproduced
Fig. 17.21, p. 442
Electrostatic Precipitator
Dirty gasDust discharge
ElectrodesCleaned gas
Fig. 17.22, p. 442
Dirty gas
Dirty water
Cleanwater
Wet Scrubber
Wetgas
Cleaned gas
Fig. 17.22d, p. 442
Cyclone Separator
Dirty gas
Dust discharge
Cleaned gas
Fig. 17.22c, p. 442
Cleaned gas
Dirty gas
Baghouse Filter Dust discharge
Bags
Fig. 17.22b, p. 442
Indoor Air Pollution/Sick Building SyndromeIndoor Air Pollution/Sick Building Syndrome
ChloroformPara-dichlorobenzene Tetrachloroethylene
Formaldehyde
Benzo--pyrene
Styrene
Radon-222Methylene Chloride
Tobacco Smoke
Carbon Monoxide
Asbestos
Nitrogen Oxides
1, 1, 1-Trichloroethane
Fig. 17.16, p. 435
RadonRadon
Radon-222 Radon-222
4 picocurie level 4 picocurie level
Occurs in certain areas based on geology
Occurs in certain areas based on geology
Associated with uranium and organic material in rock
Associated with uranium and organic material in rock
Outlet vents for furnaces and dryers
Slab jointsWood stove
Cracks in floorClothes dryerFurnace
Radon-222 gas
Slab
Radium-222
Soil
Uranium-238
Sumppump
Cracks in wallCracks in wall
Open windowOpen window
Openingsaroundpipes
Openingsaroundpipes
Fig. 17.17, p. 436
Reducing IndoorAir PollutionReducing IndoorAir Pollution
Prevention Cleanup orDilutionCover ceiling
tiles and liningof AC ducts toprevent releaseof mineral fibers
Ban smoking orlimit it to well-ventilated areas
Set stricterformaldehydeemissionsstandards forcarpet,furniture,and buildingmaterials
Prevent radoninfiltration
Use officemachines inwell-ventilatedareas
Use lesspollutingsubstitutes forharmfulcleaningagents, paints, and other products
Use adjustablefresh air ventsfor work spaces
Increase intakeof outside air
Change airmore frequently
Circulate building’s airthrough rooftopgreenhouses
Use exhausthoods for stoves andappliances burning naturalgas
Install efficientchimneys forwood-burningstoves
Fig. 17.24, p. 443