Acid rain is causing the Taj Mahal, originally white, to turn yellow due to the corrosive effects of pollution. Sulphur dioxide in the atmosphere reacts with water molecules to form sulphuric acid, which slowly dissolves the outer layer of the marble structure.
Detailed Explanation:
The primary effect of acid rain on the Taj Mahal is the gradual erosion and discoloration of its marble surface. This happens through a chemical reaction:
- Formation of Sulphuric Acid: Pollutants like sulphur dioxide (SO2), primarily from industrial emissions and vehicle exhaust, react with water vapor in the atmosphere to form sulphuric acid (H2SO4).
- Reaction with Marble: The Taj Mahal is made of marble, which is primarily calcium carbonate (CaCO3). Sulphuric acid reacts with calcium carbonate in a neutralization reaction, dissolving the marble. The reaction produces calcium sulfate, water, and carbon dioxide.
- Yellowing and Erosion: The calcium sulfate, a salt, can be washed away by rain, leading to gradual erosion of the marble. Additionally, the accumulation of particulate matter and the chemical reactions can cause a yellowing discoloration of the marble's surface.
Contributing Factors:
Several factors contribute to the impact of acid rain on the Taj Mahal:
- Industrial Pollution: Industries in the Agra region release significant amounts of sulphur dioxide and other pollutants.
- Vehicle Emissions: Increased vehicular traffic contributes to air pollution.
- Nearby Refineries: Oil refineries in the vicinity are significant sources of sulphur dioxide.
Mitigation Efforts:
Various measures are being implemented to protect the Taj Mahal from the effects of acid rain:
- Taj Trapezium Zone (TTZ): The establishment of the TTZ, a designated area around the Taj Mahal, restricts polluting industries and promotes cleaner fuel usage.
- Air Pollution Control Measures: Implementation of stricter emission standards for vehicles and industries.
- Relocation of Industries: Shifting polluting industries away from the TTZ.
- Marble Restoration and Cleaning: Regular cleaning and restoration efforts to remove discoloration and repair damage.
In summary, acid rain, caused by atmospheric pollution, significantly damages the Taj Mahal by eroding and discoloring its marble surface. Efforts are underway to mitigate the effects of pollution and preserve this iconic monument.
