APES: Unit 7
Troposphere
0-17 km above Earth's surface, site of weather, organisms, contains most atmospheric water vapor. (temperature decreases with increasing altitude, pressure decreases) Holds Nitrogen and Oxygen
Photochemical Smog - Solutions
1. Baghouse filters and scrubbers physically remove airborne pollutants from smokestacks 2. Electostatic precipitator - removes 98% of partical matter but NOT hazardous ultrafine particles, use a lot of energy, produces toxins that need to be safely disposed 3. Wet Scrubber - Remove 98% of SO2 and Particle matter - not effective in removing ultrafine particles 4. Catalytic Converters - metals react with hydrocarbons in vehicle exhaust - convert to cO2, water vapor, and nitrogen gas
Smockstack Pollution - Prevention
1. Burn coal with less sulfur 2. Remove sulfur coal 3. Switch to liquid or gas fuels 4. Cleanup/disperse emissions above thermal iversion layer (tall smokestacks)
Acid Deposition - Prevention
1. Clean Air Act - amended to cap N and SOX per power plant 2. Burn higher quality coal - wash coal before burn 3. Insulate scrubber to filter harmful chemicals from plants 4. Decrease reliance on coal by switching to cleaner Energy sources 5. Catalytic Converters
Sulfure Oxides
1. Contribute to Acid Deposition 2. Natural Causes: Volcanoes 3. Anthropogenic Causes: Coal Power Plants
Nitrogen Oxides
1. Contribute to Acid Deposition 2. Natural causes: lightning/microbes 3. Anthropogenic causes: Motor Vehicles/Power Plants
Particulate Matter
1. Indoor air pollutant - dust contains both sizes of particles and can infiltrate airways Sources: Candles, fireplaces, cooling, unvented space heaters, cigarettes Mitigation: Change heating/cooling filters often
Radon
1. Uranium - naturally occuring in soil/rocks 2. Released into atmosphere - seeps into houses/buildings - built into ground - greatest risk in poorly ventilated basements 3. 2nd Leading cause of Lung Cancer
factors that can increase air pollution
1. urban buildings (slow wind speeds and reduce dilution and removal of pollutants). 2: hills and mountains can reduce the flow of of air in valleys below them and allow pollutant levels to build up at ground level. 3: high temps promote the chemical reactions leading to photochemical smog formation, global warming could increase photochemical smog in many cities. 4: emissions of volatile organic compounds (VOCs) from certain trees and plants in heavily wooded urban areas can play a large role in the formation of photochemical smog. 5: grasshopper effect, volatile air pollutants transported by evap and winds from tropical and temperate areas through the atmosphere to earth's polar areas, then deposited.6: temp inversions cause pollutants to build to high levels.
Clean Air Act
1970- law that established national standards for states, strict auto emissions guidelines, and regulations, which set air pollution standardds for private industry Dramatically decreased air pollution
Stratosphere
2nd layer of atmosphere; extends from 10 to 30 miles up; location of ozone layer; absorbs 95% of Ultraviolet radiation; temperature increases with altitude increase.
With an inversion thermal scenario deriving from an industrial city - In addition to a nearby mountain range, which of the following environmental conditions would be required for the process in the diagram to occur
A cool sea breeze and a high pressure system Correct. A dominant high pressure system keeps the warm air from rising. At night, the Sun's energy no longer heats the air near the ground, allowing the cool sea breeze (more-dense air) to wedge underneath the less-dense warm layer. This process traps the warm layer between two cooler layers, forming the inversion.
Electrostatic Precipitator
A device used for removing particulates from smokestack emissions. The charged particles are attracted to an oppositely charged metal plate, where they are precipitated out of the air. Solution to Photochemical Smog
Primary Pollutant
A pollutant that is put directly into the atmosphere by human or natural activity
Secondary Pollutant
A primary pollutant that has undergone transformation in the presence of sunlight, water, oxygen, or other compounds
There is no representation of photosynthesis in the model environment.
A student is setting up a model to study the carbon cycle and natural sources of carbon dioxide. They create a microenvironment that contains soil, leaf debris, an earthworm, heterotrophic bacteria, and a sun lamp. What natural source of carbon dioxide and major metabolic process was left out of the model?
Indoor Air Pollutants
Asbestos, CO, Formaldehyde (pressed wood), lead, NO2, Radon, VOCs, Smoke
Monitoring the long-term chemical and biological parameters of an ecosystem
Atmospheric deposition is receiving increased attention in the scientific community, and has become the subject of a specific research area in the environmental sciences. Acid rain is detrimental to our ecosystems and can be measured in several ways. Which of the following methods would best identify changes from acid deposition in an area over time?
Limestone
Can neutralize acid deposition by combining with acids - liquid added to rivers/lakes to neutralize acid
Carbon monoxide and hydrocarbons
Catalytic converters reduce which of the following pairs of pollutants in car exhaust?
Asbestos
Composed of fibers known to cause lung disease
Carbon Monoxide
Formed during incomplete combustion of most matter Sources: Vehicle exhaust - dangerous indoors with poor ventilators
CO2
Has a stronger affinity for hemoglobin than oxygen has
add calcium carbonate to the pond water
In 1950 the pH of the pond water was 8.2, but by 2000 the pH had decreased to 5.2. An effective short-term remediation strategy for the pond would be to
A cool sea breeze and a high pressure system
In addition to a nearby mountain range, which of the following environmental conditions would be required for the process in the diagram to occur?
Which of the following points on the graph best illustrates the location where pollutants are most likely to accumulate as a result of a thermal inversion?
LOWEST POINT D
Atmospheric deposition is receiving increased attention in the scientific community, and has become the subject of a specific research area in the environmental sciences. Acid rain is detrimental to our ecosystems and can be measured in several ways. Which of the following methods would best identify changes from acid deposition in an area over time?
Monitoring the long-term chemical and biological parameters of an ecosystem Correct. To fully understand the effects of acid deposition on ecosystems, long-term studies should be conducted to evaluate soils, surface water chemistry, and living things in an area.
Photochemical Smog Formation
NO2 turns to NO + O transfers to O + O2 to form ozone. NO transfers to NO + VOCs to form Photochemical oxidants. Photochemical oxidants + Ozone = Photochemical smog.
Impacts of Acid Deposition
Nutrients are leached from topsoil Soil chemistry is changed - Toxic metal ions (aluminum, zinc, etc.) are converted into soluble forms that pollute water Affects surface water and kills fish Damages crops Erodes stone buildings, corrodes cars, erases writing on tombstones
Los Angeles, California
Of the following cities, which regularly experiences the worst levels of photochemical smog that is enhanced by thermal inversions?
VOx
Ozone - bad O3 forms 1. O2 is split by sunlight - unstable free O bonds with O2 - natural process Cause bad plant damage, carbon cycle is impacted, negative crps Contributes to Greenhouse gases
Electrostatic precipitators
Particulates can be removed from smokestack emissions by which of the following methods?
Sulfure Dioxide
Sources: Combustion of coal/oil - Volanoes/Forest Fires Respiratory issues and damage plant tissues
Lead
Sources: Gasoline (phased out), paint in older buildings, Pipes (FLINT) Toxic to central nervous system
NOx
Sources: Motor vehicle exhaust, Fossil Fuel Combustion - Forest Fires, lightning, soil microbes
Acid Deposition
Sulfur oxides and nitrogen oxides, emitted by burning fossil fuels, enter the atmosphere-where they combine with oxygen and water to form sulfuric acid and nitric acid-and return to Earth's surface
Scientists want to examine the effects of a coal-burning power plant on the pH of a lake that is downwind of the power plant. They take samples from a lake that is not downwind of the power plant to serve as a control. However, they did not realize that the lake they chose as a control group was a geothermal hot spring with acidic water. Which of the following best describes how their choice of control group could affect the results of their experiment?
The coal-burning power plant would not appear to have a large impact because the pHpH levels of the two lakes would be similar. Correct. Acid rain, as a result of pollution from the plant, would increase the acidity of the lake. If the scientists are using a control that also has acidic water, the effect of the plant would appear to be minimal because the difference in pHpH would be lower than if they used a nonacidic lake as a control.
burning of sulfur-containing fossil fuels to produce electricity
The primary cause of acid precipitation in the northeastern United States is
Thermal Inversion
The temperature inversion in which warm air traps cold air and pollutants near the earth.
Greenhouse Gases caused by
Thermal inversion created from a rise in Co2 that causes a lid of warmer air to be trapped on top of cooler, stagnant air
Long Term
To fully understand the effects of acid deposition on ecosystems, ________ ________ studies should be conducted to evaluate soils, surface water chemistry, and living things in an area
Photochemical Smog - Causes
Vocs and Nox reacting with water vapor Biggest emitter - cars
Wind direction and speed
When she looked at her data, she was surprised by how much the PM levels varied, both from site to site on a given date and over time at each site. Which of the following parameters would have been best to measure to help explain the variation in her results?
This is ozone. Ozone concentrations peak in the afternoon as the intensity of the sunlight peaks. Ozone is a secondary pollutant formed in the atmosphere in a reaction that involves both nitrogen oxides (NOxNOx) and volatile organic compounds (VOCsVOCs) in the presence of sunlight. By late afternoon, the ozone that forms during the day breaks down.
Which of the curves on the graph depicts the concentration of ozone, which requires sunlight to form?
CO2, NOx, and VOCs
Which of the following are direct products of the use of hydrocarbon fuels in automobile engines?
Dry scrubbers are less than 10% efficient at removing particles less than 1μm1μm in size.
Which of the following best describes the efficiency of dry scrubbers at removing particles that are less than 2 micrometers in diameter?
The amount of sulfur dioxide released will decrease.
Which of the following best describes the impact of modifying the slurry by increasing the amount of limestone?
Ozone maximum is correlated to average and maximum temperature.
Which of the following best describes the relationship between variables in the data table?
NO is produced by rush-hour traffic and is quickly oxidized in the atmosphere.
Which of the following best explains the pattern in NO concentration?
There will be an increase in the level of nitrogen dioxide and a decrease in the level of ground-level ozone.
Which of the following best predicts the impact of a dark and cloudy day on the readings for the levels of air pollutants measured?
CFCs (chlorofluorocarbons)
Which of the following is a primary air pollutant produced from burning coal?
Cracks in the basement foundation
Which of the following is most likely responsible for the indoor air pollutant shown in the graph? - RADON
Radon levels tend to increase in the colder months because of the difference in temperature inside and outside the home, which creates a vacuum pulling radon into the home at a higher rate.
Which of the following is the most likely reason for the trend shown in the graph of fluctuating indoor radon levels over the course of a year?
Volcanoes
Which of the following sources should be examined in a study to determine the impact of a geologic source on levels of CO2 in the atmosphere?
Parts per million
Which of the following units is used by scientists to measure CO2 in the atmosphere?
Install electrostatic precipitators at the plant.
Which of the following would be the most effective plan for the manager to propose to the city?
Decrease in the emissions of nitrogen oxides
Which of the following would most likely reduce the concentration of ground-level ozone in the air of a city?
High Pressure
________ _______ systems are needed to maintain an inversion because the descending air from above holds the less-dense, warm air close to the ground.
A thermal inversion is the result of
a lid of warm air on top of cooler, stagnant air
Catalytic Converter
a platinum, coated device that oxidizes most of the VOCs and some of the CO that would otherwise be emitted in exhaust, converting them to CO2. Solution to Photochemical Smog Prevents Acid Deposition
Dry Deposition
acidic gases and particles
Wet Deposition
acidic rain, fog, and snow
Wet Scrubber
removes 98% SO2 and PM, fine mists of water vapor trap PM and convert to sludge that is disposed in landfill Help Solve Photochemical Smog
