Sulphur Dioxide Emissions from Thermal Power Plants

#GS-3 #Environment #Pollution #Current Events #National #Sulphur Dioxide

Why in News

A recent analysis reveals that **81%** of sulphur dioxide emissions around Delhi-NCR originate from exempted coal power plants.
These industrial units operate within a **300-km** radius of Delhi and are currently excused from installing mandated pollution control systems.

Sulphur dioxide (**SO2**) is a heavy, colorless, and poisonous gas with a sharp, suffocating odor.
It is a highly reactive chemical compound and ranks among the primary air pollutants monitored under global ambient air quality standards.

Thermal power stations burning sulphur-rich coal act as the single largest industrial driver of sulphur dioxide emissions.
Oil refining and metal processing facilities that melt mineral ores such as copper, zinc, and iron release large volumes of the gas.
Natural phenomena including volcanic eruptions, geothermal hot springs, and decomposing organic matter in wetlands contribute to baseline environmental levels.

Once emitted into the air, sulphur dioxide can travel across regional airsheds over hundreds of kilometers.
The gas chemically reacts with water vapor and atmospheric oxygen to form acidic sulfate aerosols, creating dangerous **PM2.5** particulate matter.
It easily dissolves inside cloud water droplets to turn into sulphuric acid (**H2SO4**), which eventually falls as destructive acid rain.

Inhaled sulphur dioxide gas irritates human airways, triggering severe coughing and worsening conditions like asthma and bronchitis.
By producing fine particulate matter, the gas raises body inflammation, elevating the risk of strokes, heart disease, and early death.
Direct exposure destroys plant leaves and reduces photosynthesis, while acid rain strips crucial nutrients from soil and harms aquatic life.

Installing Flue Gas Desulphurisation (**FGD**) systems in thermal plants can remove up to **95%** of emitted sulphur dioxide using limestone scrubbers.
Deploying public Continuous Emission Monitoring Systems (**CEMS**) ensures real-time emission reporting to stop data manipulation by factories.
Authorities should phase out distance-based Category C exemptions because wind carries sulphur dioxide gas across long distances.
Expanding clean energy capacity through solar, wind, and battery storage will lower national dependence on coal combustion.