Unit 7 - Air Pollution

Clean Air Act (1980)

Legislation identifying 6 criteria air pollutants for EPA regulation and monitoring

Criteria Air Pollutants

SO2, NOx, CO, PM, O3, Pb - regulated by the EPA for acceptable limits

Coal Combustion

Releases SO2, NOx, CO, PM, toxic metals, and impacts air quality

Sulfur Dioxide (SO2)

From coal combustion, causes respiratory irritation, smog, and acid precipitation

Nitrogen Oxides (NOx)

From fossil fuel combustion, leads to O3 formation, acid precipitation

Carbon Monoxide (CO)

From incomplete combustion, lethal to humans, contributes to O3 formation

Particulate Matter (PM)

From fossil fuel combustion, causes respiratory irritation and smog

Ozone (O3)

Tropospheric ozone from NO2 oxidation, leads to respiratory irritation and smog

Lead (Pb)

From metal plants, neurotoxicant, and contributes to air pollution

Primary Air Pollutants

Directly emitted from sources like vehicles, power plants, and natural sources

Secondary Air Pollutants

Formed from primary pollutants in the presence of sunlight, water, and O2

Photochemical Smog

Formed by NO2, VOCs, and sunlight, impacting environment and human health

Thermal Inversion

Traps air pollutants near the surface, leading to respiratory issues and decreased tourism

Particulate Matter (PM)

Solid or liquid particles suspended in air, PM10 and PM2.5 have different sizes and health impacts

Indoor Air Pollutants

From developing and developed countries, including CO, VOCs, PM, asbestos, and radon gas

Carbon Monoxide (CO)

Asphyxiant, lethal in high concentrations, emitted from natural gas furnaces and biomass combustion

Volatile Organic Compounds (VOCs)

Easily vaporize from home products, irritate eyes and lungs, found in adhesives and cleaners

Radon Gas

Radioactive gas from decay of uranium, enters homes through cracks, and can cause health issues

Reduction of Air Pollutants

Strategies like regulations, CAFE standards, pollution credits, and vapor recovery nozzles

Catalytic Converter (CC)

Device required on vehicles after 1975 that contains metals like platinum and palladium to convert pollutants like NOx, CO, and hydrocarbons into less harmful substances.

Crushed Limestone (SO2)

Used in coal power plants to reduce SO2 emissions by combining with calcium carbonate to produce calcium sulfate, which can be used in products like gypsum wallboard.

Fluidized Bed Combustion (NOx)

Technique involving jets of air to improve combustion efficiency, reduce NOx emissions, and increase contact between coal and limestone for SO2 reduction.

Wet and Dry Scrubbers

Devices used to remove pollutants like NOx, SOx, VOCs, and particulate matter from emissions, with dry scrubbers using chemicals like calcium oxide and wet scrubbers using mist nozzles.

Electrostatic Precipitator

Device that gives particles a negative charge to trap them on positively charged plates, reducing particulate matter emissions from power plants and factories.

Baghouse Filter (PM)

Large fabric filters that trap particulate matter from industrial processes, with a shaker device to collect and dispose of the trapped particles.

Acid Rain

Caused by pollutants like NOx and SO2 reacting with water and oxygen in the atmosphere to form acids, leading to soil and water acidification, impacting plant growth, and causing environmental damage.

pH Tolerance

The ability of species to survive within a specific pH range, with deviations leading to population declines or extinctions due to factors like aluminum toxicity and disrupted osmolarity.

Mitigating Acid Rain

Involves using natural bases like limestone (calcium carbonate) to neutralize acidic soil and water, as well as reducing primary pollutants like SOx and NOx through various methods to limit acid rain effects.

Noise Pollution

Refers to excessive noise levels causing physiological stress, hearing loss, and disruption to wildlife communication and migration, with sources including urban activities, transportation, and industrial processes.