Air Pollution

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Air Pollution

• Causes, Effects, and Solutions

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Terms to be familiar with

• CAA Clean Air Act
• CO carbon monoxide
• NOx nitrogen dioxide and nitrogen oxides
• PM Particulate Matter
• SOx Sulfur dioxide and sulfur oxides
• VOCs Volatile Organic Compounds

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Our Atmospheric Composition
Composition ofdry atmosphere, by volume Composition ofdry atmosphere, by volume Composition ofdry atmosphere, by volume
ppmv parts per million by volume ppmv parts per million by volume ppmv parts per million by volume
Gas Gas Volume
Nitrogen (N2) Nitrogen (N2) 78.084 (780,840 ppmv)
Oxygen (O2) Oxygen (O2) 20.946 (209,460 ppmv)
Argon (Ar) Argon (Ar) 0.9340 (9,340 ppmv)
Carbon dioxide (CO2) Carbon dioxide (CO2) 375 ppmv
Neon (Ne) Neon (Ne) 18.18 ppmv
Helium (He) Helium (He) 5.24 ppmv
Methane (CH4) Methane (CH4) 1.745 ppmv
Krypton (Kr) Krypton (Kr) 1.14 ppmv
Hydrogen (H2) Hydrogen (H2) 0.55 ppmv
Not included in above dry atmosphere Not included in above dry atmosphere Not included in above dry atmosphere
Water vapor (highly variable) typically 1 typically 1
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Air Pollution

• Air Pollution Control Act of 1955
• 1st federal air pollution law
• 1960s - Clean Air Act of 1963
• (Emissions standards set for stationary sources
  such as power plants and steel mills)
• 1970 The Clean Air Act (CAA) of 1970
• EPA was formed to enforce air pollution laws
  (change in national policy from advisor to
  enforcer) Six major air pollutant types
• 1990 The Clean Air Act of 1990
• Clean Air Act of 1970 is re-written and new
  titles established

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Six Common Air Pollutants

• Particulate Matter
• Carbon monoxide
• Nitrogen dioxide
• Lower Troposphere OZONE producing activities
• Sulfur dioxide
• Lead
• The EPA asked to Obama Administration to consider
  Carbon dioxide as a new common air pollutant.
• Source U.S. Environmental Protection Agency-
  July 19, 2011

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Particulate Matter (PM)

• It is known as Particle Pollution and can range
  in sizes and effects on humans
• Particle sizes
• 10 um (diameter) greater health threat than
  Course particles found near roadways and in
  mining and concrete industries.

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Carbon monoxide (CO)

• CO is a colorless-odorless gas produced by the
  incomplete combustion of fossil fuels.
• Motor vehicle exhaust contributes to 56 of the
  CO produced in the U.S.
• Over 20 comes from other engines, boats and
  equipment not on-road.

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CO Pollution
EPA 1999 Data
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Updated On 11/30/2011, Published on 12/27/2011
Environmental Epidemiology Program, Bureau of
Epidemiology, Division of Disease Control and
Prevention, Utah Department of Health, Salt Lake
City, UT 84114-2104
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Nitrogen dioxide (NOx)

• Generic term for multiple combinations of
  nitrogen and oxygen
• Colorless and odorless but sometimes NO2 can be
  seen as a brown-red gas
• Sources include motor vehicles, electric
  utilities, industry, and commercial and
  residential fossil fuel usages.

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NOx is Alarming

• Contributes to the formation of acid rain
• Can contribute to nutrient load that affects
  water quality
• Contributes to Global Warming (traps long wave
  radiation on Earth) which becomes Thermal
  Radiation.

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Los Angeles California the smog is the brown
layer in the picture Source http//www.city-data
.com/picfilesv/picv8898.php
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New York city picture This 1963 photo shows a
massive smog episode in New York City. (Photo
AP/Wide World Photo, EPA Journal Jan/Feb 1990.
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OZONE

• It is not usually emitted directly into the air,
  but at ground level is created by a chemical
  reaction between oxides of nitrogen (NOx) and
  volatile organic compounds (VOC) in the presence
  of sunlight.
• Sunlight and hot weather cause ground-level ozone
  to form in harmful concentrations in the air.

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Good
Good
Ozone is Bad Here
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Ozone
There are two forms of Ozone. The Ozone that
limits UV rays from reaching the Earth is in the
Stratosphere (10 30 miles above the Earths
surface. The Bad Ozone is in the lower
Troposphere.
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Sulfur dioxide (SOx)

• Common in raw materials like coal, ore, and crude
  oil.
• Over 65 of SO2 released to the air, or more than
  13 million tons per year, comes from electric
  utilities, especially those that burn coal. 

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SOx emission
Source http//www.epa.gov/air/urbanair/so2/what1.
html
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Acadia, ME
Big Bend, TX
Bryce Canyon, UT
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Lead

• These emissions have been phased out in the U.S.,
  but NOT globally.
• The major sources TODAY are smelters, waste
  incinerators, utilities and lead-acid battery
  manufacturers.

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Notice the change in lead emission sources since
the banning of lead fuel use in the early 1980s
in the U.S.
Source http//www.epa.gov/air/urbanair/lead/what.
html
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Lead Concerns

• Affects young children and infants more
• Is still found at high levels in urban and
  industrial areas
• Deposits are in soil and water and harms animals
  and fish

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Air Pollution Health Impacts

• Air Pollutant Respiratory Other
• Particulate Matter Yes Limited
• Carbon monoxide Yes Neurologic
• Nitrogen oxides Yes Limited
• Ozone Yes Limited
• Sulfur oxides Yes Limited
• Lead Limited Organ/Neuro

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Normal Lung Aveoli (Left) versus Emphysema
(Right)
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Solutions to Industrial Emissions

• Wet Scrubbers
• Baghouse (Venturi) Filters
• Electrostatic Precipitators
• Cyclone Separators

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Wet Scrubbers

• The purge stream, which contains the particulate
  and sulfur oxides removed from the flue gas, may
  either be treated in the refinery's existing
  wastewater treatment system or may be treated in
  a dedicated PTU (Purge Treatment Unit).

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Cyclone Separators

• Cyclone dust collectors have been used as a
  pre-filter before a cartridge or baghouse
  collector,
• Effective for larger, more abrasive dust
  particles that can easily damage standard media
  filters. 

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Baghouse filter

• "Baghouse" is an example of surface filtration
• "Filter" is a membrane (sheet steel, cloth, wine
  mesh, or filter paper) with holes smaller than
  the particles.
• It is usually the cake on the filter that stops
  particles from flowing through

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Electrostatic Precipitators

• Electrostatic precipitators have collection
  efficiency of 99, but do not work well for
  flyash with a high electrical resistivity (as
  commonly results from combustion of low-sulfur
  coal). Flyash is a common emission from the
  burning of fossil fuels

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Indoor Pollutants
VOCs
Solvents (common) from paints, etc
VOCs (emitted from dishwashers)

Over-insulated homes
can cause pollutants to be held indoors
Poorly maintained heating systems
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Whats up with Carbon dioxide?

• Is it the cause of Global Warming?
• Global Climate Change

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Human-caused carbon dioxide
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Ocean pH
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