Thermal Pollution

 

THERMAL POLLUTION

“It is defines and the undesirable changes in the temperature of the water body”.

          The temperature change can be upwards or downwards.  Thermal pollution refers to release of warm water into the water body where desirable organisms are adversely affected or otherwise causes significant departures from the normal activities of aquatic communities in water.

 

Sources of Thermal pollution

·       Thermal power stations

·       Nuclear power plants

·       coal-fired power plants

·       Oil refineries

·       Steel factories

 

Effects of Thermal pollution

·       Concentration of dissolved oxygen decreases with increase in temperature of water.

·       The rising temperature increases the toxicity of the poison present in water.

·       Fishes move away from their natural habitat polluted by warm water.

·       Blue green algae and other plants grow more rapidly in warm water than in cold, but they also die more rapidly.

·       The dead and decaying algae make the water look, taste, and smell unpleasant.

·       It affects the biodiversity.

 

Control of Thermal pollution

          Thermal pollution may be controlled by the following methods.

Cooling ponds

          Discharge the heated water into shallow ponds or canals, allow it to cool, and reuse it as cooling water.

Cooling Towers

          A large cooling tower is designed to control the temperature of water.  Here, the hot water is allowed to run through a coiling pipe from top of the cooling tower;  The cool air is passed to flow up from the bottom of the tower.  After cooling, the water is drained into water bodies.

Spray ponds

          The hot water coming from the industries are allowed to pass through several sprayers.  Heat is dissipated through evaporation.

 

Cogeneration

          The Excess heat energy from generating electricity can be used in another manufacturing process that needs such energy.   Where homes or other buildings are located near industrial plants, waste hot waste can be used for heating the materials the require energy.