Sulfur Dioxide (SO2)
Effect
SO2 dissolves in rain to form acid rain which causes the erosion of buildings made of steel or concrete, the destruction of forests by increasing soil acidity, death of aquatic plants and animals in lakes and streams due to increasing acidity levels. SO2 causes eye irritation and breathing difficulties.
Solution
Calcium Carbonate (CaCO3) can be used to remove SO2 produced as flue gas from power stations and others. CaCO3 decomposes on strong heating. Both CaCO3 and CaO react with SO2. The CaSO3 will then oxidized in air to form unreactive CaSO4.
Source
Burning fossil fuels containing sulfur compounds, e.g) coal and petroleum. From volcanic eruptions.