Atmospheric pollution - smoke and smoke smog Flashcards
Define smoke
- concentration of atmospheric particulates produced by incomplete combustion of carbon
Sources of smoke
- combustion of coal, diesel, wood etc
What other toxic chemicals (or elements) can also be found in smoke
- aluminum
- lead
- acids
Effects of smoke on humans
- respiratory illnesses - asthma
- chemicals can be carcinogenic - lung cancer
- visibility
Effects of smoke on other living organisms
- reduced photosynthesis - blocks sunlight
- animal respiratory illnesses
- leaf cuticle damage
Effects of smoke on non-living objects
- damage to buildings - acids
- requires sand blasting - expensive
- adsorption
Effects of smoke on the climate and atmosphere
- reduced temperatures - high albedo
- remain suspended in the atmosphere for a long time (persistent)
- ozone depletion in the stratosphere
Define smog
- when smoke and fog are present together
What conditions increase the likelihood of smog formation
- requires fog
- cold air reaches its duel point - moisture content is too high to be held as vapor
- temperature inversions
What is a temperature inversion
- layer of warm air above layer of cold air in the troposphere - smoke trapped at low levels
Conditions that make a temperature inversion more likely to form
- cold temperatures
- clear night skies
- valleys
- low wind velocities
What happens to pollutant gases during a temperature inversion
- trapped closer to ground level - more dense than the air above
Why is smoke in fog more dangerous than smoke alone
- pollutants trapped closer to the surface
> harmful chemicals are more likely to be inhaled - may react synergistically (water and chemicals)
What are the 9 smokey control measures
- clean air act (1956)
- change in domestic behaviour
- improvements to vehicles
- electrostatic precipitator
- cyclone separator
- scrubber
- coal treatment
- bag filters
- improved combustion efficiency
What is the clean air act (1956)
- series of laws
- banned emissions of black smoke
- introduced smokeless fuels
- mostly in large urban areas
What is change in domestic behaviours
- change the way we eat and cook
- less reliance on coal and diesel at home
- mostly homes rely on gas and electricity
What is improvements to vehicles
- diesel particulate filters (diesel vehicles)
- remove up to 80% of particulates upon combustion
- move away from diesel cars
- move to electric cars
What is an electrostatic precipitator
- effluent gases from combustion of coal etc are passed through an electrostatic precipitator
- metal plates inside are charged
- plates attract particulates - waste gases continue and are released to the atmosphere
What is a cyclone separator
- like a vacuum
- air sucked into it
- rotates - things with high mass or density are forced to stick to the outside wall of the CS - they stick and collect at the bottom
- air released at the top
What is a scrubber
- water sprays
- remove particulates
What is coal treatment
- treated by heating coal
- remove tarr like substance
- tarr contains the particulates
- makes the coal smokeless
What is a bag filter
- passing waste gases through a membrane/filter
- small enough to collect particles in the bag and air passes through
- produces clean air
What is improved combustion efficiency
- incomplete combustion of fuel
- turbo charges - ^ O2 to engine, leads to full combustion of fuel
- driver educations/behaviour
> fast acceleration
What is photochemical smog
- air pollution that happens when sunlight reacts with certain pollutants like car exhausts
