Atmosphere and photochemical smogs

Question 1

Atmospheric pollution different behaviour because;

Answer 1

• rapid dispersal

- interaction with EM radiation i.e.UV —> secondary pollutant

Question 2

Smoke and smoke smogs

Answer 2

Atmospheric particulates produced by incomplete combustion of C-based materials:
P10 - particulate matter less than 10 microns diameter
P5
P1
Smaller = atmosphere longer increase likelihood up inhalation

Question 3

Smoke and smoke – main sources

Answer 3

• Urban areas –Combustion of coal diesel general and bustable wastes
• Rurel areas – Combustion of Crop waist, wood fuel, grassland, forests

Question 4

Smoke and smoke pollution Effects

Answer 4

• humans – respiratory disease - Chems kill cilia in brochioles, increase difficult exhale wastes - ^ infection risk , chems may be carcinogenic
• Decrease photosynthesis
  Damage buildings - acids + organic solvents, cleaning expensive
• decrease temperature albedo
  – Small particles atmosphere long time especially in stratosphere
• stratospheric smoke depletes the ozone

Question 5

Smoke smogs

Answer 5

Smoke and fog = smog
Fog form when my circles to dew point - water vapour condensed to airborne droplets- Temp inversions make fog more likely
smoke more easily inhaled as smog
Temp inversions make smog last longer, high albedo pollutants rise

Question 6

Smoke pollution - controls

Answer 6

• legislation - clean air act 1956
• domestic sources - ^ use non smoke fuel
• transport sources - dispersal particulate filter in exhausts
  -industrial sources
  + electrostatic precipitation - effluent gases passed through charged electrical wires/ plates attract smoke particles - accumulate and fall as ash
  + Cyclone separator – gases. In cylindrical chamber, gases rotate, suspended particles on outside collect and fall.
  + scrubber - fine waste spray washes out suspended solid particles and dissolved soluble matter
  + coal treatment- heating allow tar to be drained off smokeless coal
  + bag filter - Remove smoke particles trapped in fabric filter and increase efficiency combustion tech
  + Turbo charger is allowed what are so more oxygen to combustion chamber increase and combustion efficiency

Question 7

Photochemical smogs

Two main components

Answer 7

NOx ( car engine and fertilisers)
Hydrocarbons - Partly burnt fuel, hydrocarbon extraction - natural gas often burnt and aerosols, solvents – evaporate/escape into atmosphere

Question 8

Photochemical smog – impacts of nitrous oxides

Answer 8

Increase risk respiratory infection ie. colds, flu, brochitus. Heart disease and asthma worse

Question 9

Photochemical smog – and packs of hydrocarbons

PANs

Answer 9

• bad 4 Health and respiratory
• formsmog
• PANs - toxic at much lower conc. then NOx - eye irritation, breathing difficulties, asthma, emphysema, heart attacks

Question 10

Photochemical smog is chemical reactions

Answer 10

See textbook

Question 11

Photochemical smog is – controll

Of NOx

Answer 11

NOX and hydrocarbons controlled using exhaust pipe catalytic converters - platinum and palladium.
NOx chemically reduced in catalytic converter is to reform oxygen and nitrogen gases
Catalytic converter is used and exhaust system

Question 12

Photochemical smog control of unburnt hydrocarbons

Answer 12

• catalytic converter is oxidised hydrocarbons to carbon dioxide and water
• Vapours at filling stations can be collected, condense, and return to the main fuel tank
• papers can be collected and passed through and activated carbon filter where the hydrocarbons absorb onto the carbon particles