causes of thermal pollution

Thermal Pollution

Presented byPratika Rane

Msc. Biotechnology Part 1

Introduction Thermal pollution is the degradation of water qualityby any process that changes ambient watertemperature. Many industries use high temperature furnace andboilers in their manufacturing processes. The resultinghot effluents are directly released in to a nearby watersource.

Nuclear power plant

Coal fired power plants

Domestic sewage

Industrial effluentsHydro-electric power

plantsDeforestation

Causes of Thermal Pollution

Nuclear power plant 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.

Emissions from nuclear reactor increase the temperature of water bodies.

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

Domestic sewageSewage 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.

Industrial effluentsDischarged water from steam-electric power industry using turbo generators will have a higher temperature ranging from 6 to 9˚C than the receiving waterIn 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

Hydro-electric power plantGeneration of hydroelectric power sometimes results in negative thermal loading in water systemsCreates less heat on water sources less than nuclear power plant

Deforestation Trees and plants prevent sunlight from falling directly on lakes, ponds or rivers. When deforestation takes place, these water bodies are directly exposed to sunlight, thus absorbing more heat and raising its temperature. Deforestation is also a main cause of the higher concentrations of greenhouse gases i.e. global warming in the atmosphere.