1. Acid Deposition

2. What is acid deposition?
dry deposition:
 conversion of sulphur dioxide and nitrogen oxides into sulphates and nitrates
rain containing greater amounts of acid than “normal”
conversion of sulphur dioxide and nitrogen oxides into sulphuric and nitric acid
low pH (<5.6)
sulphuric acid
carbonic acid
nitric acid

3. What causes acid rain? Natural occurrences of: sulphur dioxide
carbon dioxide
nitrogen oxides
Plant respiration, volcanic activity, atmospheric gases
 The Role of Human Activity:
Transport
Industry
Vehicle exhausts emit nitrogen oxides from their exhausts.
Power stations burning fossil fuels with high sulphur content.

5. Acids (carried by prevailing winds) can travel up to 2000km within 5 days
Acids taken into solution by cloud and rain droplets
Polluting gases react with oxygen in the atmo-sphere to produce dilute forms of sulphuric acid & nitric acid.
The acids run through rivers, into lakes and are taken into the hydrological cycle.
Acid rain falls and lands on vegetation and soaks into soil.

6. What are the impacts of acid deposition?
direct effects:
e.g. acid on coniferous woodland
Toxic effects:
e.g. aluminium ions on fish
nutrient effects:
e.g. leaching calcium
How can acid deposition be tackled?
Describe and evaluate pollution management strategies for acid deposition:
measures to reduce fossil fuel combustion
clean up measures at points of emissions
role of international agreements