Unit 7 Flashcards
Causes and effects of SO2
Cause: Coal Combustion
Effect: Irritates respiratory system, Acid Precipitation, Smog
Causes and effects of NOx
Causes: all fossil fuel combustion, coal especially
Effects: Tropospheric Ozone, photochemical smog, Acid Precipitation
Causes and effects of CO
Causes: incomplete combustion of fossil fuels
Effect: bonds to hemoglobin in blood and suffocates people
Causes and effects of PM
Causes: fossil fuel and biomass combustion
Effects: Respiratory irritation, Smog
Causes and effects of O3
Causes: photochemical oxidation of NO2
Effects: Respiratory irritation, Smog, Damages Plants
Causes and effects of Lead
Causes: mental plants, waste incineration, old paint
Effects: neurotoxin (harms nervous system and development)
Is CO2 an air pollutant under the Clean Air Act? Why?
No, it does not directly lower air quality for human health. It is not toxic to breath in, but it does heat the atmosphere.
What type of fossil fuel releases the most air pollutants?
Coal combustion
Vehicles made after 1974 must have _______ to reduce _____ and ____ emissions.
Catalytic converters, NOx, CO
Primary Air Pollutants
pollutants emitted directly from the source (vehicles, power plants, factories
Ex. SO2, NOx, CO
Secondary Air Pollutants
Pollutants that have gone through a transformation in the atmosphere in the presence of sunlight, H2O, or O2.
Ex. nitric acid, tropospheric O3
What are factors that increase smog formation?
More traffic
Hotter temperature
More VOCs
More electricity demand
How can we reduce? smog?
decrease the number of vehicles on the road
increased electricity production from renewable energy sources
How does smog impact plants?
smog reduces sunlight and limits photosynthesis.
How does smog impact humans?
irritates the reparatory system (worsening asthma and bronchitis)
How does smog impact the economy?
-increased healthcare cost puts a strain on the economy
-Loss of worker productivity
-decreases agricultural yields
Urban Heating Island
the idea that cities have a hotter average surface temperature then the surrounding rural and suburban areas.
What causes the Urban Heating Island?
Lower albedo: concrete and asphalt absorb more of the suns energy then grass.
Less evapotranspiration: evaporation of water from plants brings heat back to the atmosphere.
Thermal Inversion
a cooler air mass becomes trapped near earth’s surface causing a sandwich of warm air between two masses of cold air.
Effect of thermal inversion
Air pollutants become trapped near the earth’s surface because the pollutants no longer rise with the hot air
Examples of PM 10
pollen, dust, ash, mold
Examples of PM 2.5
particles from combustion
What does aerobic decomposition release?
CO2
What does anaerobic decomposition release??
CH4
What is Radon Gas?
radioactive gas that is released by the natural decay or Uranium underground. It seeps through groundwater or cracks in house foundations.
What year di the EPA ban the use of lead paint?
1978
Clean Air Act
allows EPA to set acceptable levels for the emission of air pollutants
Pollution Credits
companies can get credits from the government for reducing emissions below the EPA standards. These credits can then be sold to other companies.
CAFE vehicle Standards
(Corporate Average Fuel Economy) standards that require US vehicles to meet fuel economy standards.
Vapor Recovery Nozzles
a separate tube inside the gas pump that captures VOCs released from gas fuel when refueling.
Catalytic Converter
Converts NOx, CO, and hydrocarbons emitted by cars into CO2, N2, O2 and H2O
Required since 1975
Crushed Limestone
Mixed with coal to reduce the SO2 emitted from coal plants
Dry Scrubbers
Large Collums filled with chemicals that absorb or neutralize oxides.
Wet Scrubbers
Chemicals that are sprayed in a large collum to absorb or neutralize NOx, VOCs, SOx
Fluidized Bed Combustion
jets of air pumped into combustion bed to increase the amount of O2 in the combustion reaction, making combustion more efficient.
-allows coal to be combusted at a lower temperature, therefor producing less NOx
Electrostatic Precipitator
Emissions pass through a device that gives them a negative charge, so they stick to positively charged plates.
Baghouse filter
a fabric bag filter that traps PM from emissions
Environmental effects of acid rain
-leach positively charged nutrients from the soil (K+, CA2+)
-make toxic metals more soluble in water
Methods for mitigating acid rain
Limestone: provides a natural buffer for the effects of acid rain
Limiting SO2 and NOx: reduce the chemicals that lead to acid rain
Urban Noise Pollution
any noise that has great enough volume to lead to physiological stress
