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On Tonight’s News Channel…On Tonight’s News Channel…

At School…

Hey guys, don’t you

ever wonder why the air’s so bad now?

Must be all the CO Mr Chiu keeps going on

about

No! It’s the NOx!

You girls are so dumb

It’s the SOx

It’s the VOCs

Or the Particulates

…

Actually…

…THEY’RE ALL RIGHT

Sharon

Composition of Air

Air is composed of around 78% Nitrogen, 21% Oxygen, 1% Argon and 0.03% CO2.

An excess of any of these gases or the presence of

unwanted gases, which may harm the environment or our health, are AIR POLLUTANTS!

The Main Pollutants Are…

Carbon Monoxide

Particulates

Sulfur Oxides (SOx)

Nitrogen Oxides (NOx)

Volatile Organic Compounds (VOCs)

Sammy

Carbon MonoxideOne of the sources of CO is the incomplete combustion of methane, or CH4.

CH4 (g) + 1.5O2(g)  CO(g) + 2H2O(g)

Another source is from the combustion of fossil fuels, such as coal.

C8H18(g) + 8.5O2(g) 8CO(g) + 9H2O(g)

2CH4(g) + 3O2(g) 2CO(g) + 4H2O(g)

One of the sources of CO is the incomplete combustion of methane, or CH4.

CH4 (g) + 1.5O2(g)  CO(g) + 2H2O(g)

Another source is from the combustion of fossil fuels, such as coal.

C8H18(g) + 8.5O2(g) 8CO(g) + 9H2O(g)

2CH4(g) + 3O2(g) 2CO(g) + 4H2O(g)

Nitrogen Oxides

Nitrogen naturally comes from thunder storms and biological processes.

Combustion engines in jets or cars also produce NO

N2(g) + O2(g) 2NO(g) 

2NO(g) + O2(g) 2NO2(g)

Nitrogen naturally comes from thunder storms and biological processes.

Combustion engines in jets or cars also produce NO

N2(g) + O2(g) 2NO(g) 

2NO(g) + O2(g) 2NO2(g)

Sulfur OxidesThe combustion of coal is a man-made source of SO2 and SO3.

S(g) + O2(g) SO2(g)

2S(g) + O2(g) 2SO3(g)

Volcanoes also emit SO2.

2H2S(g) + 3O2(g) 2SO2(g) + 2H2O(g)

The combustion of coal is a man-made source of SO2 and SO3.

S(g) + O2(g) SO2(g)

2S(g) + O2(g) 2SO3(g)

Volcanoes also emit SO2.

2H2S(g) + 3O2(g) 2SO2(g) + 2H2O(g)

Volatile Organic CompoundsPartially burned fuels such as gasoline produce VOCs.

The usage of  solvents, paints, wax and some cosmetic products wax will also produce VOCs.

Plants naturally emit these pollutants in the form of terpenes (hydrocarbons with the formula C10H16)

Partially burned fuels such as gasoline produce VOCs.

The usage of  solvents, paints, wax and some cosmetic products wax will also produce VOCs.

Plants naturally emit these pollutants in the form of terpenes (hydrocarbons with the formula C10H16)

Particulates

Particulates are naturally found in the atmosphere in the form of dust, soot, sand, smoke, pollen, and ash.

The combustion of fossil fuel also emits particulates.

Particulates are naturally found in the atmosphere in the form of dust, soot, sand, smoke, pollen, and ash.

The combustion of fossil fuel also emits particulates.

Test Yourself!

Which 2 pollutants will burning fossil

fuels produce?

What pollutant is the car

producing?

What compound will the electrical

storm generate?

What gas will the volcano

emit?

What gas arises from the decay of organic matter?

Phew finally some fresh air!

How do we keep it this way though?

Methods of Reduction…Reduce CO, NOx and VOCs by using a catalytic converter, which converts these compounds into

CO2 and water.

Use lean burn engines to reduce CO and NOx, which increase efficiency of engines

by reducing throttling losses.

Removing sulfur from fossil fuels such as coal and using in power plants will decrease SO2

emissions.

The level of particulates can be greatly reduced by using sedimentation chambers, which purifies the air, and electrostatic precipitation, which also

removes particulates from flowing gases.

THE END!