Thursday, December 8, 2011

Thermal pollution and Effects of Thermal pollution

Number of industrial processes may utilize water for cooling From cooling process, resultant warm water has been discharged into water bodies.Generators which run on fuel like coal or oil and automatic energy plants causes waste heat on large scale which is carried away as hot water that causes thermal pollution.

Thermal pollution can be defined as Presence of large amount of waste heat in the receivig water which cause: harmful effects in natural environment's Most often the term thermal pollution is used for detrimental effect of heated discharges. It do not involve the impairment of purity neither heat is pollutant. Raising or lowering of temperature leads the impairment of environmental air or water quality. Abut 80% of total water with drawn for industrial orations is used for cooling only. The industrial plants that contribute the thermal loading of surface water with prime concern are : 1) Thermal plants ii) Nuclear plants. Steam electric power plants alone with its discharge in water increases 6* to 100 temperature of receiving water. Some times negative thermal loading also takes place during hydel power generation. About 18 percent more heat is required to cooling water nuclear power plants than fossil fuelplants.


Municipal sewage, steel plants. cement factories are also the constrictors of thermal pollution, sewage without treatment discharges into canal or steams. Domestic sewage normally has higher temperature than the receiving water which raises stream temperature to a measurable extent. Increase intemperately of receiving water decreases the dissolved oxygen level of the same hence anaerobic conditions please foul gases. The aquatic organisms which depend on the dogtrot the water will die Heated industrial effluents when discharged into river, lake. ponds or sink also have similar effects and chats instability to aquatic ecosystem.


Effects of Thermal pollution :
Life process involves many reactions, which varies accordingly temperature changes. It also influences on physiology,digestion, Rate of respiration and reproduction is condoned by
temperature.
1) Aquatic animals are affected on large scale by thermal Pollution Particularlyfish population and fish species due to Potential  hazards
2) Surface watery are the habitat for wider variety of flora and fauna of which. existence and survival depend on aquatic environment.
3) Concentration of dissolved oxygen depend on temperature of surface water. Increase in surface water temperature decreases dissolved oxygen. eg. DO.
4) The rate of biochemical reaction and PH is determined by temperature of water.
5) sharp and sudden changes in surface water temperature have destructive effects on aquatic ecosystem. D.O. Concentration at 0.C is 14.6 ppm which at 35% is 7.1 ppm.
6) Increase in temperature leads metabolic and respiration inference in biotic. Sometimes death due to failure of nervous system take place.
7) Reproductive mechanism gets affected and duranal seasonal behaviour of organisms gets changed. 
8) Higher the temperature of surface water.

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