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Thermal Pollution

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What is Thermal Pollution?

The broadest definition of thermal pollution is the degradation of water quality by any process that changes ambient water temperature. Thermal pollution is usually associated with increases of water temperatures in a stream, lake, or ocean due to the discharge of heated water from industrial processes, such as the generation of electricity. Increases in ambient water temperature also occur in streams where shading vegetation along the banks is removed or where sediments have made the water more turbid. Both of these effects allow more energy from the sun to be absorbed by the water and thereby increase its temperature.


Causes of Thermal Pollution:-

Water used as coolant & ejected back into water bodies:– Mainly, the water that is used as coolant and transferred back to natural water bodies is the chief reason for thermal pollution. This kind of activity is mostly done by production; manufacturing and power plants. These plants use water to cool down their machines and eject back the hot water into water bodies. Thus, the natural water goes through a sudden rise in temperature.

Release of cold water:– Just as we mentioned before, many industries liberate very cool water from their reservoirs. This water when mixed up with warm water rivers, lakes or ponds creates a dis balance in the flora and fauna of affected water bodies.

Chemical pollutants discharged into water:– There are copious factories that discharge their chemical waste directly into natural water bodies. This does not only causes thermal pollution but also makes the water poisonous.

Human waste, household & personal care products:– These products go into sewage water which pollutes the water in ponds, seas and other water bodies.

Deforestation & soil erosion:– Soil erosion makes natural water bodies to rise beyond their normal level. Thus, they get more exposed to sunlight. Hence, the temperature of water rises. Forests absorb much of sun rays and save water bodies from getting too much heat.

Natural Geo-thermal activities:– Natural geothermal activities can stimulate lava and can cause a rise in water temperature, making way for thermal pollution.

Unawareness among people:– Growing thermal pollution is also the result of unawareness among people. Even after knowing the hazardous effects of thermal pollution on environment, there are abundant industries which are continuously using ways that encourage this pollution.


Effects of Thermal Pollution:-

Depleted level of oxygen in natural water:– When warm water discharged by industries enters the natural water bodies, they get heated up. The warm water causes an unusual growth of plants and expansion of algae. The algae expansion in water reduces the level of oxygen in water.

Contamination of water:– Thermal pollution also results in contamination of water because various chemicals and other wastes get mixed up with the water that is disposed of back to rivers, ponds, lakes, etc., by various factories. If this contamination of water keeps on increasing, humans can suffer from shortage of water.

Reduced solubility of oxygen:– Reduced solubility of oxygen in water bodies is another disappointing effect of thermal pollution. This less solubility of oxygen in water mainly affects the metabolism of water animal.

Adverse effect on water plants and animals:– Change in temperature levels is extremely harmful for the aquatic plants. These plants cannot cope up with the sudden alteration in water temperature. Hence, more and more aquatic plants are depleting each day because of thermal pollution. The whole marine life gets disturbed because of thermal pollution. The contaminated water makes the natural water poisonous and has an adverse effect on animals living in it. Also, the reduced level of oxygen makes it difficult for water animals to survive.

Disturbance in biological activities of water animals:– Thermal pollution leads to a disturbance in quality and temperature of water in various water bodies. This altered quality and temperature directly affect all the biological activities of animals, thus disturbing the cycle of nature.

Unfavourable Effect on Water Biodiversity:– Thermal pollution largely affects the water bio diversity. The rise in temperature of water results in increased metabolic activity of some water animals. Hence, they start consuming more food in short time. This also leads to shortage of certain water resources. Some animals which are unable to stand the raised temperature start moving to other regions. Therefore, the whole natural system of water bio diversity gets disturbed.

Unexpected Migration of Water Animals:– When water animals find it difficult to survive in the changed water because of thermal pollution, they start for an unexpected migration, making way for a disturbed ecosystem.


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Thermal Pollution prevention, monitoring and solution:-

Use less electricity:– All of us know that power plants are the main reasons behind growing thermal pollution. This is so because power plants use water as a cooling agent for cooling down their machines. This used water, which is much higher in temperature, is discharged back into the rivers, seas or lakes. We can make a significant contribution in controlling thermal pollution by consuming less electricity,. The use of less electricity will lead to less workload on power plants and these plants will not have to use their machines too much, meaning controlled use of water as coolant.

Use of Better Technologies:– Science has gifted us with plentiful inventions, discoveries, techniques and knowledge. Incorporating good techniques ensure a good lifestyle for human race. Use of better technologies is strongly recommended for solving the problem of thermal pollution. There are technologies available which help in the cooling down of machines. If machines will be cooled down with the help of technologies, the use of water as coolant will come to a much reduced level. Various industries and power plants should look out for appropriate technologies that serve the purpose without encouraging the steady problem of thermal pollution.

Holding back the water for good:– If factories or plants cannot stop using water as a coolant, there is another option available for them. After using the water as coolant, they should store that water somewhere else for a temporary period. Instead of discharging back the heated water into water bodies, the temporarily collected heated water can be used for various other purposes too. Storing the heated water for a particular time will help in bringing back the high temperature of water to a normal level.

Plantation of more trees upon the banks of rivers, seas & other water bodies:– This is also a good way to control thermal pollution. The trees around sources of water help in absorbing the harsh sun rays and prevent them from falling directly upon the water. This helps in prevention of heating of water bodies. Planting more trees also helps in controlling the problem of soil erosion because the strong roots of trees hold the soil firmly and stop it from erosion. Trees do not only help in controlling thermal pollution but also aid in a better environment including fresh air and peaceful scenic views. We should also encourage our coming generations to plant more and more trees.

Artificial Lakes:– Industries, factories or plants which are serious about storing and reusing the heated water, used as coolant, can work out on artificial lakes. These are artificial lakes where the heated water can be stored easily. These lakes are very helpful for normalizing the temperature of hot water. This way, the hot water will not be disposed back to the lakes, rivers, etc., and will be used in other suitable tasks. Actually, the artificial lakes or ponds use evaporation or convection technique for cooling down the water. These artificial lakes or ponds generally contain two ends. From one end, the hot water is transferred into the lake; it is processed through evaporation or other technique and finally, when it cools down, it is taken out from the other end. The evaporated heat dissolves in the air.

Spreading awareness among people:– Environment can be made better with a united effort. Making more and more people aware about the problem of thermal pollution will be very beneficial in the long run. Groups of people can initiate a discussion with different plants and industries.

Cooling towers:– Cooling towers is also a good idea when talking about the solutions for thermal pollution. The purpose of using cooling towers is the same as artificial lakes. The cooling towers also use the hot water of industries, process it by transferring its heat and transform hot water into cold water. This cool water can be recycles and used again for different industrial purposes.


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