APES Unit 7 Atmospheric Pollution

Coal

A fossil fuel that forms underground from partially decomposed plant material, contains sulfur

Combustion

the process of burning something

Air pollution

Concentration of trace substances, such as carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, and solid particulates, at a greater level than occurs in average air

sulfer dioxide

SO2, a gas produced by coal burning which increases the acidification of rain water

Mercury

Hg, toxic metal released from fossil fuel combustion

PM 10

Particulates that are less than 10 microns in diameter. These particulates are present in the smoke created by burning wood.

PM 2.5

particulates less than 2.5 microns, particles are capable of being inhaled deeply into the lungs, particles are not cleared readily from the body

Nitrous oxides

NOX,Various gaseous compounds, including NO2 and NO3, which commonly result from industrial processes involving combustion.

trophospheric ozone

O3, Ozone that occurs in the troposphere, where it is a secondary pollutant created by the interaction of sunlight, heat, nitrogen oxides, and volatile carbon containing chemicals.

Hydrocarbons

organic molecules consisting of carbon and hydrogen

Clean Air Act

1970- law that established national standards for states, strict auto emissions guidelines, and regulations, which set air pollution standards for private industry

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

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

photochemical smog

A brownish haze that is a mixture of ozone and other chemicals, formed when pollutants react with each other in the presence of sunlight

Formaldehyde

An air pollutant that is a colorless chemical used to manufacture building materials and many household products, such as particleboard, hardwood plywood paneling, and urea-formaldehyde foam insulation.

Respiratory

relating to the lungs

Industrial smog

found in cities that burn large amounts of coal, Type of air pollution consisting mostly of a mixture of sulfur dioxide, suspended droplets of sulfuric acid formed from some of the sulfur dioxide, and suspended solid particles.

Thermal inversion

The temperature inversion in which warm air traps cold air and pollutants near the earth.

natural air pollution

dust, wildfires, volcanoes, and plants

Carbon monoxide

a colorless, odorless, and poisonous gas, bonds with hemoglobin getter than oxygen in the blood

Asphyxiant

substance that can cause unconsciousness or death by suffocation

Asbestos

A long, thin, fibrous silicate mineral with insulating properties, which can cause lung cancer when inhaled.

indoor air pollution

Compounds that affect breathing that occur indoors. Examples: woodstove smoke, furnace emissions, formaldehyde, radon, household chemicals, tobacco smoke

Radon 222

may cause damage to respiratory tissue when inhaled (lung cancer); is product of uranium decay and is an indoor pollutant, found in rocks/soil

VOCs

Volatile organic compounds: Hydrocarbon solvents used in paints, stains and other products that are released into the air during the application of coatings and react with nitrous oxides and sunlight to form ozone.

lead

Pb, impacts nervous system, kidney function, immune system, reproductive and developmental systems

Sulfur oxide

(SOx) Primary source is coal burning. Primary and secondary effects include acid deposition, respiratory irritation, plant damage. Reduction methods include: scrubbers, burn low sulfur fuel.

Particulates

Small particles released into the atmosphere by many natural processes and human activities

Vapor recovery nozzle

reduces air pollution by capturing vapors that escape from a fuel tank

Catalytic converter

device in vehicles that oxidizes most of the VOCs and some of the CO that would otherwise be emitted in exhaust, converting them to CO2.

Wet scrubber

removes 98% SO2 and PM, fine mists of water vapor trap PM and convert to sludge that is disposed in landfill

dry scrubber

Chemical reactions

Removing SOx from a combustion gas

Electrostatic precipitators

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.

pH scale

scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic

Anthropogenic

Human-induced changes on the natural environment

Acidification

The lowering of the pH of a solution.

Limestone

a hard sedimentary rock, composed mainly of calcium carbonate or dolomite, used as building material and in the making of cement.

calcium carbonate

CaCO3

acid rain effects

corrodes metals and buildings, depletes fish populations, birds lay thin eggs, leach aluminum from soil, weaken forest ability to withstand cold

Mitigation

the action of reducing the severity, seriousness, or painfulness of something

Noise pollution

Any unwanted, disturbing, or harmful sound that impairs or interferes with hearing, causes stress, hampers concentration and work efficiency, or causes accidents.

100 dB

At what level can sounds damage the ears?

What legislation was formed in 1970 to deal with air pollution?

Clean Air Act

Environmental scientists and human health scientists were consulted and developed a list of six pollutants that significantly threaten human well-being, ecosystems and structures.  List these six pollutants

 SO2, NOx, CO, PM, Tropo O3, Pb

What gas was added in 2007?

CO2

What is the main anthropogenic source of sulfur dioxide?

combustion of fuels that contain sulfur(coal, oil, gas)

What is the main natural source of sulfur dioxide?

volcanic eruptions, forest fires

The atmosphere is 78% nitrogen gas, and all combustion in the atmosphere leads to the formation of _____

some nitrogen oxide

What are the main anthropogenic sources of NO_x?

FF combustion, wood, and other biomass burning

What are the main natural sources of NO_x?

Forest Fires, lightning, microbial activity in soils

How does CO form?

during incomplete combustion of most matter

List the main anthropogenic sources of PM

combustion of coal, oil, and diesel, and of biofuels(manure and wood); ag , road construction, other activities that mobilize soot, soil, and dust

List the main natural sources of PM

Volcanoes, Forest Fires, and Dust Storms

Why is the smaller PM considered a greater health concern than the larger PM?

Bc our nose hairs/throats don't filter it out which leads to it entering deep into our respiratory tract and tend to be composed of more toxic substances than larger particles

What is haze?

reduced visibility; especially when PM from air pollution scatters light

What does the “photo-” part of photochemical smog mean?

sunlight

A secondary pollutant made up of three oxygen atoms is ozone and impairs the function of what human system?

Respiratory system

What is the difference between Los-Angeles-type smog and London-type fog?

LA=brown smog(photochemical and dominated by sulfur dioxide and sulfate compounds); London=grey smog(industrial and dominated by the burning of FF particularly coal which releases SO2 and PM)

What was the main anthropogenic source of lead before 1975?

added to gas so it was released into the air and travelled by winds or deposited on ground by rain/snow

Lead and mercury are both known to damage what human system?

nervous system

List three examples of VOCs

hydrocarbons(gas, lighter fluid, dry-cleaning fluid, oil-based paints, and perfumes)

Explain the difference between primary and secondary pollutants, and describe HOW each is formed

Primary: polluting compounds that come directly out of a smokestack, exhaust pipe, or nat emission source(formed released when FF are burned); secondary:undergone transformation in the presence of sunlight, water, O2, or other compounds(happens more during hot/wet periods)

What makes the Smoky Mountains appear smoky?

created by the VOCs released from the dense vegetation

What are the NAAQS?

National Ambient Air Quality Standards

How does temperature influence smog formation? Why?

the chem reactions that form ozone and other photochem oxidants proceed more rapidly at higher temps bc warmer temps cause vegetation to release more VOCs, NOx emissions from AC on warmer days, evaporate volatile liquids faster(ex. gas)

How would you predict a thermal inversion would influence smog formation?

A thermal inversion is when less dense(bc its closer to earth) cold air is below more dense(bc its further from earth) warm air which causes pollutants to be trapped closer to earth instead of being dispersed from the movement of the warm air.

Study figure 47.3 and describe how acid deposition forms.

SO2 and NOx are released in the atm and with reactions with O2 and H2O cause them to form H2SO4 and HNO3 which respectively get broken down into (2H+ and SO4^2-) and (H+ and NO3^-). Over many days the pollutants travel and are deposited as precipitation or in dry form on veg, soil, or water

Is acid deposition a local, regional, or global problem?  Explain

A global problem because many countries individually struggle with it, but some regions might have acid deposition that travels to other regions where it actually deposits causing it to become a global problem

List the environmental, economic, and human health impacts associated with acid rain

Envi: decrease in pH of waters, low pH=mobilization of metals(metals bound in org/inorg compounds in soils/sediments are released into surface waters→can lead to species loss); Econ: Trees can be damaged in acid rain which causes the lumbar industry to lose out in profit, ; Human: acid rain doesn’t harm skin but the precursors to acid deposition(SOx and NOx) do, harm/deteriorate human made structures(esp limestone)

What two air pollutants are major contributors to smog formation?

NOx and VOCs

Why is indoor air pollution a bigger problem in developing countries?

Because people burn biomass(manure, wood, coal) in open pit fires that lack the proper mix of fuel and air to complete combustion→typically there is no exhaust system and little-no ventilation available in the space(makes CO and PM a hazard in developing countries)

Why is indoor air pollution a problem in developed countries?

People have begun to spend more time indoors, tightly sealed buildings keep existing air in contact with the inhabitants of buildings for greater amounts of time, increased number of materials are made from plastics/petroleum-based materials that give off chemical vapors

Describe fluidized bed combustion?

Granulated coal is burned in close proximity to calcium carbonate, the heated CaCO3 absorbs SO2 and produces CaSO4 which can be used in the production of gypsum wallboard(sheetrock for houses); some sulfur oxide that does escape the combustion process can be captured by other methods after combustion

What is the purpose of a car’s catalytic converter?

reduces nitrogen oxide and carbon monoxide emissions(has precious metals in it→platinum and palladium which cannot be exposed to Pb so gasoline cant have Pb in it anymore)

What is a scrubber and what is its purpose?

uses a combination of water and air that actually separates and removes particles; particles are removed in the scrubber in  liquid or sludge form and clean gas exits

How is static electricity used to control particulate matter?

uses an electric field to give particles a charge then attracting them to collector plates with the opposite charge(Electrostatic precipitators)

List at least 3 other ways that pollution is being reduced

restrict the evaporation of dry-cleaning fluids/restrict use of lighter fluid(VOC) for starting charcoal barbecues; restrict use of wood burning stoves or fireplaces; restrict number of bakeries in a certain area(not very popular)