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
What pollutants are involved with the formation of photochemical smog
NOX’s
O3
Hydrocarbons
What effects to NOX’s have
- respiratory problems
- acid rain
What effects to tropospheric O3 have
- respiratory issues
- decreased lung function
What effects to Hydrocarbons have
- climate change
- breathing difficulties