Thermal Pollution and its harmful impacts

content related to source of thermal pollution and its impacts

1. Definit i on Addition of excess of undesirable heat to water that makes it harmful to Man, Animal & Aquatic Life

2. Causes Di s c ha rg e of Hea t ed Wat e r O r H o t Waste Material into Water bodies from Nuclear Power Plants Industrial Effluents Domestic Sewage Hydro-Electric Power Coal Fired Power Plants

3. Suf f oca t ed fish Low d i ss o l v ed oxygen Decreased fish population Altered food web Thermal Pollution

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

5. Industrial Effluents Disc h arg e d wate r from industry using t u rb o g e n e rators temperature ste a m- e l e c t ri c power wil l have a hig h er ranging from 6 to 9 ˚C than the receiving water In modern stations, producing 100 MW, nearly one million g a llo n s are di s c h ar g ed i n a n hour wi t h increase in temperature of the cooling water passing by 8 to 10 ˚C

6. Domestic sewage Sewage is commonly discharged into lakes, canals or streams Municipal sewage normally has a higher temperature than the receiving water Increase in temperature of the receiving water decreases the DO of water. The foul smelling gases increased in water resulting in death of marine organisms

7. Hydro electric power generation Generation of hydroelectric power sometimes results in negative thermal loading in water systems Creates less heat on water sources less than nuclear power plant

8. Coal-fired power plants Coal is utilized as a fuel Condenser coils are cooled with water from nearby lake or river The heated effluents decrease the DO of water Damages the marine organisms

9. Effects of Increased Water Temperature Thermal 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 decreases Increases the rate of photosynthesis, which increases the amount of plant growth Increases the metabolic rate of fish, which increases their need for oxygen

10. Dissolved Oxygen vs. Temp

11. CONTROL MEASURES Cooling towers Cooling ponds Spray ponds Artificial lakes