What is Thermal Pollution?
Thermal pollution occurs due to a sudden change in the temperature of water bodies, mostly by human activities. 'Thermal' means heat, so it is mainly caused due to heating up of water bodies.
Causes of Thermal Pollution
The use of water as a coolant for power plants and factories is a common reason behind thermal pollution. Human activities like water disposal from power plants, domestic sewage, industrial effluents are the chief contributors to thermal pollution. Natural sources like volcanoes and hot springs also cause thermal pollution but of a lesser effect.
What are the Effects of Thermal Pollution?
Thermal pollution affects aquatic life by causing thermal shock (a sudden increase or decrease in water temperature). Some aquatic organisms are not able to adapt to the temperature change, and as a result, they die. Oxygen is not soluble in warm water, causing some organisms to die due to anoxia (lack of oxygen supply to the body).
The water released from power plants contains chemicals like nitrogen and phosphorus. The algae and bacteria in water bodies feed on them and grow uncontrollably on the water surface, which is known as algae bloom. This hampers the supply of oxygen and sunlight into the water body, resulting in the death of useful aquatic organisms. This process is known as eutrophication.
How can Thermal Pollution be Reduced?
Thermal pollution can be controlled by:
- Treating the disposed water to remove any harmful chemicals
- By reusing the disposed water from the industries
- By installing artificial lakes for industrial uses