Thermal pollution, causes, effects, Control Measures

2. Definition
Addition of excess of
undesirable heat to water that
makes it harmful to Man, Animal
& Aquatic Life

3. Causes
Discharge of Heated Water Or Hot Waste
Material into Water bodies from
 Nuclear Power Plants
 Industrial Effluents
 Domestic Sewage
 Hydro-Electric Power
 Coal Fired Power Plants

4. Suffocated
fish
Low
dissolved
oxygen
Decreased fish
population
Altered food web
Thermal Pollution

5. 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 9-20oC warmer

6. Red – reservoirs Yellow – Fossil Plants Purple – Nuclear Plants

7. Waste Heat from Power Plants

8. Industrial Effluents
Discharged water from steam-electric power
industry
using turbo generators will have a higher
temperature
ranging from 6 to 9˚C than the receiving water
In modern stations, producing 100 MW, nearly one
million gallons are discharged in an hour with
increase
in temperature of the cooling water passing by 8
to 10 ˚C

9. 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

10. 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

11. 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

12. 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

13. Dissolved Oxygen
vs. Temp

14. The
Future is
Now

15. CONTROL MEASURES
 Cooling towers
 Cooling ponds
 Spray ponds
 Artificial lakes