ARE 309 - Chapter 4 Clean Air Act - Part 1 · major source is the automobile engine. Chapter 4 –...

Chapter 4 – Part 1-

ARE 309 - Chapter 4Clean Air Act - Part 1

© 2003 J.M. Kuszaj

Slide 4- 1Clean Air Act

Chapter 4The Clean Air Act (CAA)


Part 1:Air Pollutants & Sources


What You Should Know

● Two basic physical forms of air pollution

● Two major sources of air pollution● What is a primary/secondary air

pollutant● Criteria pollutants

– Descriptions and major sources

● Non-criteria air problems


Two Basic Physical Forms of Air Pollution● Particles

– Small, discrete masses of solid or liquid matter– Examples: Dust, smoke, mists and fly ash

● Gases– Widely separated molecules in rapid motion– Examples: Carbon monoxide, sulfur dioxide


Primary & Secondary Pollutants● Primary Pollutants

– Emitted into the atmosphere directly from identifiable sources

– Found in the atmosphere in the same chemical form as when emitted from the source

● Secondary Pollutants– Undergo chemical changes in the atmosphere as a

result of reactions among two or more pollutants


Primary PollutantExample● Carbon Monoxide (CO)



© 2003 J.M. Kuszaj


Secondary PollutantExample● In the presence of sunlight● Oxygen (O2) reacts with ● Nitrogen oxides (NOX) and ● Volatile organic compounds (VOCs)● To produce ozone (O3)



Air Pollution Source Categories

● Stationary or Mobile

● Combustion or Non-Combustion

● Point or Area


Stationary or Mobile


Combustion or Non-Combustion


Point or Area



© 2003 J.M. Kuszaj


Five Emission Generation Categories● Transportation● Stationary Source Fuel Combustion● Industrial Processes● Solid Waste Disposal● Miscellaneous

– Forest Fires, Fugitive Dust



Not So Obvious Air Pollution Sources


Air Pollutant

Ammonia Emission From Hog Farms


The Major Air PollutantsCriteria Pollutants

● Sulfur Dioxides (SO2)● Particulate Matter (PM10)● Carbon Monoxide (CO)● Ozone (O3)● Nitrogen Oxides (NOx)● Lead (Pb)


Why “Criteria” Pollutants ?



© 2003 J.M. Kuszaj


Criteria Pollutants

Pollutant Form Type Sulfur dioxide gaseous Primary

Particulate matter particulate Primary

Carbon monoxide gaseous Primary

Ozone gaseous Secondary

Nitrogen oxides gaseous Primary

Lead particulate Primary


Sulfur Dioxide (SO2)

● Colorless● Highly corrosive gas● Formed when fuels containing sulfur

are burned– Coal– Oil


Sulfur Dioxide (SO2)


Particulate Matter

● Microscopic Airborne Soots ● Size Matters

– Total Suspended Particulate > 50 micrometers

– PM-10 - Coarse particles < 10 micrometers– PM-2.5 - Fine particles < 2.5 micrometers

● Heath Effects– TSP (settles out of air)– PM-10 & PM-2.5 (inhalable)


Particulate Matter

● Microscopic Airborne Soots ● Size Matters

– Total Suspended Particulate > 50 micrometers

– PM-10 - Coarse particles < 10 micrometers– PM-2.5 - Fine particles < 2.5 micrometers

● Heath Effects– TSP (settles out of air)– PM-10 & PM-2.5 (inhalable)


Particulate Matter - Sources

● Coarse -- Unpaved roads, materials handling, and crushing and grinding operations, as well as windblown dust.

● Fine particles -- Fuel combustion



© 2003 J.M. Kuszaj


Particulate Matter (PM-10)

● Visible smoke from leaf and trash fires is made up almost entirely of particulate matter


Carbon Monoxide (CO)

● Colorless, odorless, tasteless gas● Formation:

– Formed when carbon in fuel is not burned completely

● Sources– Motor Vehicles - 60%– Natural Sources - 40 %

» Wild fires


Ozone (O3)

● Primary ingredient of smog● Formation:

– Secondary pollutant formed by the reaction of NOx and VOC’s in heat & sunlight

● Sources:– Nitrogen oxides from motor vehicles, power plants, and

other sources of combustion– VOCs from a variety of sources, including motor vehicles,

chemical plants, refineries, factories, consumer and commercial products, and other industrial sources


Ozone (O3)

● Good and Bad Ozone


Volatile Organic Compounds(VOC)

● Defined:– Substances containing carbon and different

proportions of other elements such as hydrogen, oxygen, fluorine, chlorine, bromine, sulfur, or nitrogen; these substances easily become vapors or gases

● Sources:– Paints, paint strippers, and other solvents; wood

preservatives; aerosol sprays;


Nitrogen Oxides (NOx)

● Two gases– Nitric Oxide (NO)– Nitrogen Dioxide (NO2)

● Sources– Natural Sources (50%)– Man-Made Sources: High-temperature combustion

processes, such as those occurring in automobiles and power plants



© 2003 J.M. Kuszaj


Lead (Pb)

● Gray metal

● Formation:– Naturally occurring material

● Sources:– Burning leaded gasoline– Paints and leaded pipes



Category: Criteria Pollutants

The Answer Is:

Very small pieces of liquid or solid matter


Category: Criteria PollutantsThe Answer Is:

Secondary pollutant that forms when hydrocarbons and nitrogen oxides react in the presence of heat and sunlight.



Grey metal: gasoline and paint formerly contained this material.



Colorless, odorless and tasteless gas: One major source is the automobile engine



© 2003 J.M. Kuszaj



Colorless gas. One major source is the fossil-fuel combustion. The “pass-through” pollutant”



Two harmful gases of nitrogen. About 50% comes from natural sources. Of human sources, motor vehicles are the largest source.


How Are We Doing on Controlling Criteria Pollutants






© 2003 J.M. Kuszaj


Generic Air Quality Problems

● Acid Rain

● Greenhouse Gases

● Ozone Depletion

● Regional Haze


Acid Rain


Acid Rain

Criteria Pollutants

NOx

SO2

Nitric Acid

Sulfuric Acid

Sunlight

Water Vapor


Acid Rain


How Do We Measure Acid Rain?

The pH scale measures acidity

pH = 5.6


Controlling Acid Rain

● Control the sources

● SO2 sources ?

● NOx sources ?



© 2003 J.M. Kuszaj


Greenhouse Effect


Greenhouse Effect


Greenhouse Gases(Both natural & man-made)

● Carbon dioxide (CO2)

● Methane

● Nitrous oxide (N2O)

● Halocarbons


Generating Greenhouse Gases

● Using energy from fossil fuels

● Vegetation cover

● Farming

● Breakdown of wastes

● Industrial processes


Greenhouse Effect

● Good ?

● Bad ?


Greenhouse Effect

● There is a greenhouse effect, but, if there were not, we would all be dead!

● Global Warming is different



© 2003 J.M. Kuszaj


Global Warming

● Global warming is the name given to an expected increase in the magnitude of the greenhouse effect, whereby the surface of the Earth will almost inevitably become hotter than it is now


Greenhouse Gases

● Criteria Pollutants ?


Regional Haze

Great Smoky Mountains

Clear

Hazy


What Is Haze

● When sunlight encounters tiny particles in the air

● Some light is absorbed, some is scattered

● Amount of light reaching viewer is reduced


Haze Pollutants

● Particulate matter

● SO2 forming Sulfates

● Sulfates absorb more light


Regional Haze - Pollutants

SO2



© 2003 J.M. Kuszaj


Controlling Regional Haze

● Control the source

● SO2 sources

● Particulate sources


Ozone Depletion Process

● CFC Released● CFC rise into ozone layer● UV releases chlorine from CFC● Chlorine destroys ozone● Depleted ozone allows more UV● More UV = more skin cancer



CFC

● Chloroflurocarbons– Chlorine– Fluorine– Carbon

● Commonly used as:– refrigerants– solvents, – foam blowing agents


Controlling Ozone Depletion

● Control the production of

● Ozone Depleting Substances (ODS)– CFCs– Halon– Methyl chloroform

ARE 309 - Chapter 4 Clean Air Act - Part 1 · major source is the automobile engine. Chapter 4 –...

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