THERMAL POLLUTION By: NIKHIL PAKWANNE

What is Thermal Pollution?Increase in the normal temperatures of natural waters caused by intervention of human activities.Temperature is a physical characteristic of water which is characteristic of water which is regulated under the Clean Water Act.

Thermal Pollution

Major CausesNuclear power plantsDeforestationSoil erosion

Nuclear Power PlantsNuclear power plants use water as a cooling agent.After the water is used, it is put back into a water supply at 9-20oC warmer

This 1988 thermal image of the Hudson River highlights temperature changes caused by discharge of 2.5 billion gallons of water each day from the Indian Point power plant. The plant sits in the upper right of the photo hot water in the discharge canal is visible in yellow and red, spreading and cooling across the entire width of the river. Two additional outflows from the Lovett coal-fired power plant are also clearly visible against the natural temperature of the water, in green and blue.

Waste Heat from Power Plants

DeforestationThe decrease in vegetation increases the amount of light that hits the water, which increases the temperature of the waterDeforestation also increases erosion

Soil ErosionErosion makes the water muddy, which increases the light absorbed

Effects of Increased Water TemperatureThermal shock aquatic life adapted to a certain water temperature can go into shock when the temp is changed even 1 or 2 degrees.Oxygen dissolved in water decreasesIncreases the rate of photosynthesis, which increases the amount of plant growthIncreases the metabolic rate of fish, which increases their need for oxygen

Changes in the environment may also result in amigration of organisms to another, more suitable environment, and to in-migration of organisms that normally only live in warmer waters elsewhere. As a result one has the problem of compromising food chains of the old and new environments. Biodiversity can be decreased as a result.Biotic Effects of Thermal Pollution

Changes of even one to two degrees Celsius can cause significant changes in organism metabolism and other adverse cellular biology effects. Principal adverse changes can include rendering cell walls less permeable to necessary osmosis, coagulation of cell proteins, and alteration of enzyme metabolism. These cellular level effects can adversely affect mortality and reproduction.

Dissolved Oxygen

vs

Temp

Control of thermal pollution

Cooling ponds, man-made bodies of water designed for cooling byevaporation,convection, and radiationCooling towers, which transfer waste heat to theatmospherethrough evaporation and/orheat transferCogeneration, a process where waste heat is recycled for domestic and/or industrial heating purposes

References: http://thermal.unl.edu/dmwww.thermaleffects.comwww.google.com http://thermalpollution.usda.edu/dt