Unit 6.4 Acid Deposition

Question 1

What are the effects of acid deposition on soil, water, and living organisms?

Answer 1

• weaken tree growth
• decrease the pH of water bodies affecting aquatic life
• increase the solubility of toxic metals
• lead to the leaching of soil nutrients.

Question 2

What are the anthropogenic sources for air pollutants?

Answer 2

CO2 = burning fossil fuels and deforestation
CH4 = biofuels, livestock farming and landfills
NOx = motor vehicle exhausts and burning fossil fuels

Question 3

What causes acid deposition?

Answer 3

Main primary pollutants
- sulphur dioxide (S02)
- Nitrogen oxides (NOx)
react with water to form strong acids (sulphuric and nitric acids).

Question 4

What are natural sources of pollutants?

Answer 4

Volcanic eruptions (SO2)
Lightning (NOx)

Question 5

How does acid deposition affect human-made structures?

Answer 5

Acid deposition can damage limestone buildings and statues, including those of archaeological and historical value, by causing them to dissolve.

Question 6

Strategies for altering the human activity that produces pollution

Answer 6

• Replace fossil fuels with alternatives like ethanol for cars and renewable energy sources for electricity.
• Reduce overall demand for electricity through education campaigns to turn lights off, insulate houses, etc.
• Encourage the use of less private transport by carpooling, using public transport, walking, or cycling.
• Use low-sulfur fuels, remove sulfur before burning, or burn mixed with limestone.

Question 7

Evaluation on the strategies for altering human activity to reduce pollution?

Answer 7

• Reducing CO2 emissions is important, but economies are currently reliant on fossil fuels.
• The power demand is increasing, especially in industrializing countries like India and China.

Question 8

Strategies for regulating and reducing pollutants at the point of emission

Answer 8

• Implement clean-up technologies such as scrubbing in chimneys to remove sulfur dioxide.
• Use catalytic converters to convert nitrous oxides back to nitrogen gas.

Question 9

Considerations when evaluating strategies for regulating and reducing emissions

Answer 9

• Technologies can be expensive and the costs are often passed on to the consumer
• Catalytic converters are cost-effective if well maintained but are expensive to purchase.

Question 10

Cleanup and restoration strategies for damaged environments

Answer 10

• Lime-acidified lakes and rivers.
• Recolonize damaged areas and lime forestry plantations, as trees can acidify soils as they remove nutrients.
• Establish international agreements for environmental protection.

Question 11

Considerations when evaluating cleanup and restoration strategies

Answer 11

• Liming is effective in restoring pH but must be repeated regularly, which can be costly.
• Recolonization can affect biodiversity in other ways.
• International agreements are challenging to establish and monitor.