Thermal pollution refers to the degradation of water quality as a result of any process that changes the ambient water temperature.
A common cause of thermal pollution is the use of water as a coolant by power plants (thermal and nuclear) and industries.
The water used as a coolant returned to the water sources like rivers, lake, etc at a higher temperature.
So, let us see an example for power plants, the discharge of heated water, which is at least 15°C higher than the normal water into a water body.
Causes or Sources of Thermal Pollution
The various causes of thermal pollution are as follows:
Nuclear power plants
Nuclear power plants emit a large amount of unutilized heat and traces of toxic radioactive substances into the nearby streams.
Effluents from the nuclear reactors and processing installation are also responsible for increasing the temperature of water bodies.
Coal-fired power plants
Some thermal power plants use coal as fuel. Thus, Coal-fired power plants constitute the major source of the thermal pollution.
Industries like steel industry use water for cooling which when disposed of in water bodies causes thermal pollution.
Industries generating its electricity also requires a large amount of cooling water for heat removal.
Furthermore, other industries like textile, paper and pulp and sugar industry release heat in water, but to a lesser extent.
Sewage is often discharged into rivers, lakes or streams without any treatment. So, the sewage normally has a higher temperature than the receiving water.
Generation of hydroelectric power results in negative thermal loading of water bodies.
Effects of Thermal Pollution
Many organisms are killed intently by the hot water and disturb the river ecosystem.
Warm water holds less oxygen than cold water and affects the river’s flora and fauna.
With the increase in temperature of the receiving water the dissolved oxygen (DO) content decreases and the demand for oxygen increases and anaerobic conditions occur.
So, the egg of fish may hatch early or fail to hatch at all.
It may change the diurnal and seasonal behavior and metabolic response of organisms.
Thus, it may lead to unplanned migration of aquatic animals.
The rise intemperate of the atmosphere may lead to global warming and melting of polar ice caps.
Control Measures of Thermal pollution
Control of thermal pollution is necessary as it has adverse effects on the aquatic ecosystem. Thermal pollution can be controlled by passing the water through
Large shallow cooling pond: water enters into the pond form one end. So, as a large surface area of water exposed to the atmosphere, there is the dissipation of the heat and the cooler water remove from the other end.
- By using cooling towers: The heat is dissipated into the air and water can be discharged into the river or pimped back to the plant to be reused for cooling.
- By using spray ponds.
The disadvantage of all the methods that a lot of water lost in evaporation.
Role of Individual in Prevention of Pollution
There are lots of environmental problems causes from the human side in the environment. We must recognize that each of us is individually responsible for the quality of the environment we live in.
Our actions worsen or improve the quality of our environment. Several people feel that environmental problems can solve with the quick technological solution.
While most individuals want the cleaner environment, not many of them want to make the changes in their lifestyle that would contribute to the cleaner environment.
Each should change his or her lifestyle in such a way as to reduce environmental pollution. It can do with the following suggestions.
- Develop respect for all forms of life.
- Help more in pollution prevention than pollution control.
- Plant more trees and take care of them. They reduce air pollution.
- Use eco-friendly products.
- Reduce your dependency on fossil fuel especially coal or oil.
- Try to avoid asking plastic bags when you buy vegetable glossary, instead use of cloth bags.
- Avoid buying the components/things containing CFC as it destroys the ozone layer.
- Save electricity by not wasting it.
- Adopt popularize renewable sources.
- Reduce the use of wood and paper products.
- Promote reuse and recycling wherever possible and reduce production of waste.
- Use pesticides only when necessary and that too in the right amount.
- Use rechargeable batteries. Rechargeable batteries will reduce metal pollution.
- Use organic manure instead of commercial inorganic fertilizers.
- Do not put pesticides, paints solvents oils or other harmful chemicals into the drain or groundwater.
- Use only the minimum required amount of water for various activities. This will prevent fresh water from pollution.
- Check population growth so that the demand of the material is under control.