Acid rain is caused due to air pollution by?

Acid rain is primarily caused by air pollution from emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx). Here’s how these pollutants lead to the formation of acid rain:

1. Sulfur Dioxide (SO2):
– SO2 is emitted into the atmosphere mainly from burning fossil fuels containing sulfur, such as coal and oil in power plants, industrial facilities, and vehicles.
– In the atmosphere, SO2 reacts with oxygen and water to form sulfuric acid (H2SO4):
\[
\text{SO}_2 + \frac{1}{2}\text{O}_2 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{SO}_4
\]
– Sulfuric acid is a strong acid that contributes to the acidity of rainwater.

2. Nitrogen Oxides (NOx):
– NOx are produced during combustion processes, particularly in vehicles and industrial facilities.
– In the atmosphere, NOx reacts with oxygen and water to form nitric acid (HNO3):
\[
\text{NO}_x + \text{O}_2 + \text{H}_2\text{O} \rightarrow \text{HNO}_3
\]
– Nitric acid is also a strong acid that contributes to acid rain.

3. Formation of Acid Rain:
– When sulfuric acid and nitric acid dissolve in rainwater, they lower its pH, making it more acidic than normal rainwater (which has a pH around 5.6 due to carbonic acid from carbon dioxide in the atmosphere).
– Acid rain can also deposit as dry particles (dry deposition) or in fog or snow, affecting ecosystems, buildings, and infrastructure.

Acid rain can have detrimental effects on aquatic ecosystems, forests, soil quality, and human health. Efforts to reduce emissions of sulfur dioxide and nitrogen oxides, such as through stricter emission controls and the use of cleaner technologies, are crucial in mitigating the impacts of acid rain.