Acid rain

Acid Rain

The branch on the left is from a tree in the Black Forest in Germany.What has caused it to change colour and shape?

The Formation of Acid Rain

Burn fossil fuels in

Transport, Industry, Homes, power

stations

The rest reacts with sunlight and ozone in the atmosphere; nitric (HNO3), and sulphuric acid (H2SO4) are produced

Gas, Oil, Coal

Some falls back to Earth close to the source as dry particles, gas and aerosols (NOx and SO2) (dry deposition)

NO2CO, CO2, SO2

It is dissolved in the moisture in the atmosphere making

2H+ and SO42_

and can be carried large distances before falling as rain or snow (wet deposition)

TRANSBOUNDARY POLLUTION

H2O

H+ NO3

_ SO4

2_

Transboundary deposition

• The countries that are producing the majority of the Pollution that causes acid rain (Britain, Germany, USA) aren’t that badly affected by acid rain.

• Instead, the wind direction means the acid rain falls elsewhere (in Europe this affect Scandinavia; USA affects Canada).

The Result

Acids activate aluminium from the soil which leaches into water and fish die. Drinking water is contaminated

This stand of trees near Most, Czech Republic, has completely died.

Buildings and precious stone objects are weathered away as the stone reacts with the acid

When soil is contaminated, planting production drops

How might the effects of acid rain be reduced?

Burning coal which contains less sulphur

Remove sulphur from coal before it is used

Remove sulphur from waste gases after it is used (Flue gas desulphurisation)

Using unleaded petrol

But …

It costs

Tales a long time to phase out thermal power stations

Impact on coal mining industry as demand falls

International agreements to reduce sulphur dioxide emissions

Add lime to lakes affected by acidification

Switch to alternative energy supplies

Energy conservation methods