Acid rain is one of the consequences of air pollution. It occurs when emissions from factories, cars or heating boilers contact with the water in the atmosphere. These emissions contain nitrogen oxides, sulphur dioxide and sulphur trioxide, which when mixed with water become sulphurous acid, nitric acid and sulphuric acid. This process also occurs naturally through volcanic eruptions.
Causes of acid rain
Acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulphur dioxide (SO2) and nitrogen oxides (NOx) resulting from fossil fuel combustion. The burning of fossil fuels (coal and oil) by power-production companies and industries releases sulphur into the air that combines with oxygen to form sulfur dioxide (SO2).
Effects to environment
Acid rain can harm the environment. Some fish and animals, such as frogs, have a hard time adapting to and reproducing in an acidic environment. Many plants, such as evergreen trees, are damaged by acid rain. Acid-rain damage to the evergreen forests in the Black Forest of Germany. Many of our historic buildings and monuments are located in the areas of highest acidity. Acid precipitation affects stone primarily in two ways: dissolution and alteration. When sulfurous, sulfuric, and nitric acids in polluted air react with the calcite in marble and limestone, the calcite dissolves.
How to control acid rain?
- Use less energy (hence less fuel burnt)
- Use cleaner fuels
- Remove oxides of sulphur and oxides of nitrogen before releasing
- Use other sources of electricity (i.e. nuclear power, hydro-electricity, wind energy, geothermal energy, and solar energy)
- Powdered limestone/limewater added to water and soil to neutralize acid