However, thermal pollution is a real and persistent problem in our modern society. In layman’s terms, thermal pollution is when an industry or other human-made organization takes in water from a natural source and either cools it down or heats it up. Wanted Water Quality Board Actions1. The Water Quality Board requests TDEC conduct a study of the cumulative water quality impacts of the thermal pollution caused by existing and proposed power generating plants on the Tennessee River, including the climatic scenarios of prolonged drought and warmer temperatures.2. Thermal pollution is defined as the addition of undesirable excess heat to water, making it harmful to human, animal or aquatic life. Thermal pollution can also lead to significant deviations from the activities of aquatic communities.
The Brayton Point Power Station in Massachusetts discharged heated water to Mount Hope Bay.[1] The plant was shut down in June 2017.[2]
Thermal pollution is the degradation of water quality by any process that changes ambient water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Other causes of thermal pollution include soil erosion. This will elevate water and expose it to sunlight. When water used as a coolant is returned to the natural environment at a higher temperature, the sudden change in temperature decreases oxygen supply and affects ecosystem composition. Fish and other organisms adapted to particular temperature range can be killed by an abrupt change in water temperature (either a rapid increase or decrease) known as 'Thermal shock.'
Urban runoff—stormwater discharged to surface waters from roads and parking lots—can also be a source of elevated water temperatures.
- 1Ecological effects
- 2Sources and control of thermal pollution
Ecological effects[edit]
Potrero Generating Station discharged heated water into San Francisco Bay.[3] The plant was closed in 2011.[4]
Warm water effects[edit]
Elevated temperature typically decreases the level of dissolved oxygen and of water, as gases are less soluble in hotter liquids. This can harm aquatic animals such as fish, amphibians and other aquatic organisms. Thermal pollution may also increase the metabolic rate of aquatic animals, as enzyme activity, resulting in these organisms consuming more food in a shorter time than if their environment were not changed.[5]:179 An increased metabolic rate may result in fewer resources; the more adapted organisms moving in may have an advantage over organisms that are not used to the warmer temperature. As a result, food chains of the old and new environments may be compromised. Some fish species will avoid stream segments or coastal areas adjacent to a thermal discharge. Biodiversity can be decreased as a result.[6]:415–17[7]:340
High temperature limits oxygen dispersion into deeper waters, contributing to anaerobic conditions. This can lead to increased bacteria levels when there is ample food supply. Many aquatic species will fail to reproduce at elevated temperatures.[5]:179–80
Primary producers (e.g. plants, cyanobacteria) are affected by warm water because higher water temperature increases plant growth rates, resulting in a shorter lifespan and species overpopulation. The increased temperature can also change the balance of microbial growth, including the rate of algae blooms which reduce dissolved oxygen concentrations.[8]
Temperature 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 enzymemetabolism. These cellular level effects can adversely affect mortality and reproduction.
A large increase in temperature can lead to the denaturing of life-supporting enzymes by breaking down hydrogen- and disulphide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as the inability to break down lipids, which leads to malnutrition. Increased water temperature can also increase the solubility and kinetics of metals, which can increase the uptake of heavy metals by aquatic organisms. This can lead to toxic outcomes for these species, as well as build up of heavy metals in higher trophic levels in the food chain, increasing human exposures via dietary ingestion. [8]
In limited cases, warm water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is seen especially in seasonal waters and is known as thermal enrichment. An extreme case is derived from the aggregational habits of the manatee, which often uses power plant discharge sites during winter. Projections suggest that manatee populations would decline upon the removal of these discharges.
Cold water[edit]
Thermal Pollution Experiment
Releases of unnaturally cold water from reservoirs can dramatically change the fish and macroinvertebrate fauna of rivers, and reduce river productivity. In Australia, where many rivers have warmer temperature regimes, native fish species have been eliminated, and macroinvertebrate fauna have been drastically altered. This may be mitigated by designing the dam to release warmer surface waters instead of the colder water at the bottom of the reservoir.[9]
Thermal shock[edit]
When a power plant first opens or shuts down for repair or other causes, fish and other organisms adapted to particular temperature range can be killed by the abrupt change in water temperature, either an increase or decrease, known as 'thermal shock'.[7]:208[10]:478
Sources and control of thermal pollution[edit]
Cooling tower at Gustav Knepper Power Station, Dortmund, Germany
Industrial wastewater[edit]
In the United States, about 75 to 82 percent of thermal pollution is generated by power plants.[7]:335 The remainder is from industrial sources such as petroleum refineries, pulp and paper mills, chemical plants, steel mills and smelters.[11][12] Heated water from these sources may be controlled with:
- cooling ponds, man-made bodies of water designed for cooling by evaporation, convection, and radiation
- cooling towers, which transfer waste heat to the atmosphere through evaporation and/or heat transfer
- cogeneration, a process where waste heat is recycled for domestic and/or industrial heating purposes.[13]
Some facilities use once-through cooling (OTC) systems which do not reduce temperature as effectively as the above systems. For example, the Potrero Generating Station in San Francisco (closed in 2011), used OTC and discharged water to San Francisco Bay approximately 10 °C (20 °F) above the ambient bay temperature.[14]
A bioretention cell for treating urban runoff in California
Urban runoff[edit]
During warm weather, urban runoff can have significant thermal impacts on small streams, as storm water passes over hot parking lots, roads and sidewalks. Storm water management facilities that absorb runoff or direct it into groundwater, such as bioretention systems and infiltration basins, can reduce these thermal effects. These related systems for managing runoff are components of an expanding urban design approach commonly called green infrastructure.[15]
Retention basins (stormwater ponds) tend to be less effective at reducing runoff temperature, as the water may be heated by the sun before being discharged to a receiving stream.[16]
See also[edit]
References[edit]
- ^'Brayton Point Station: Final NPDES Permit'. NPDES Permits in New England. U.S. Environmental Protection Agency (EPA), Boston, MA. 2014. Retrieved 2015-04-13.
- ^Finucane, Martin (2017-06-01). 'Mass. says goodbye to coal power generation'. Boston Globe.
- ^Selna, Robert (2009). 'Power plant has no plans to stop killing fish.'San Francisco Chronicle, January 2, 2009.
- ^Pacific Gas & Electric Co. 'Potrero Power Plant: Site Overview.' Accessed 2012-07-17.
- ^ abGoel, P.K. (2006). Water Pollution - Causes, Effects and Control. New Delhi: New Age International. ISBN978-81-224-1839-2.
- ^Kennish, Michael J. (1992). Ecology of Estuaries: Anthropogenic Effects. Marine Science Series. Boca Raton, Florida: CRC Press. ISBN978-0-8493-8041-9.
- ^ abcLaws, Edward A. (2000). Aquatic Pollution: An Introductory Text. New York: John Wiley and Sons. ISBN978-0-471-34875-7.
- ^ abVallero, D.A. in (2019). Letcher, T.M.; Vallero, D.A. (eds.). ”Thermal Pollution” pp. 381-388 in Waste: A Handbook for Management. Amsterdam, Netherlands and Boston MA, Print Book: Elsevier Academic Press. ISBN9780128150603. 804 pages.}}
- ^Mollyo, Fran (15 September 2015). 'A happier environment for fish'. Phys.org. Retrieved 15 September 2015.
- ^Chiras, Daniel D. (2012). Environmental Science. Burlington, MA: Jones & Bartlett. ISBN9781449614867.
- ^EPA, Washington, D.C. (May 2014). 'Technical Development Document for the Final Section 316(b) Existing Facilities Rule.' Document No. EPA 821-R-14-002. p 4-2.
- ^EPA (June 2006). 'Technical Development Document for the Final Section 316(b) Phase III Rule.' Document No. EPA 821-R-06-003. Chapter 2.
- ^EPA (1997). 'Profile of the Fossil Fuel Electric Power Generation Industry'(PDF). Office of Compliance, Sector Notebook Project. p. 24. Archived from the original on 2011-02-03. Document No. EPA/310-R-97-007.
- ^California Environmental Protection Agency. San Francisco Bay Regional Water Quality Control Board. 'Waste Discharge Requirements for Mirant Potrero, LLC, Potrero Power Plant.'Archived 2011-06-16 at the Wayback Machine Order No. R2-2006-0032; NPDES Permit No. CA0005657. May 10, 2006.
- ^'What is Green Infrastructure?'. EPA. 2015-11-02.
- ^EPA (August 1999). 'Preliminary Data Summary of Urban Storm Water Best Management Practices.' Document No. EPA-821-R-99-012. p. 5-58.
- Langford, Terry E.L. (1990). Ecological effects of thermal discharges. Pollution Monitoring Series. London: Elsevier Applied Science. ISBN1-85166-451-3.
- Hogan, Michael; Patmore, Leda C.; Seidman, Harry (August 1973). Statistical Prediction of Dynamic Thermal Equilibrium Temperatures using Standard Meteorological Data Bases. Washington, D.C.: EPA. EPA-660/2-73-003.
- Thackston, E.L.; Parker, F.L. (March 1971). Effect of Geographical Location on Cooling Pond Requirements. Water Pollution Control Research Series. Washington, D.C.: EPA. EPA-830-R-71-001.
- Edinger, J.E.; Geyer, J.C (1965). 'Heat Exchange in the Environment'. New York: Edison Electric Institute.
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Thermal_pollution&oldid=900182242'
When someone thinks of pollution, the idea of thermal pollution often doesn’t come to mind. People will first think of things like carbon emissions, personal pollution and waste, and a variety of other changing factors. However, thermal pollution is a real and persistent problem in our modern society. In layman’s terms, thermal pollution is when an industry or other human-made organization takes in water from a natural source and either cools it down or heats it up. They then eject that water back into the natural resource, which changes the oxygen levels and can have disastrous effects on local ecosystems and communities.
Thermal pollution is defined as sudden increase or decrease in temperature of a natural body of water which may be ocean, lake, river or pond by human influence. This normally occurs when a plant or facility takes in water from a natural resource and puts it back with an altered temperature. Usually, these facilities use it as a cooling method for their machinery or to help better produce their products.
Plants that produce different products or waste water facilities are often the culprits of this massive exodus of thermal pollution. In order to properly control and maintain thermal pollution, humans and governments have been taking many steps to effectively manage how plants are able to use the water. However, the effects are still lasting today.
Causes of Thermal Pollution
Ppt On Thermal Pollution
1. Water as Cooling Agent in Power, Manufacturing and Industrial plants: Production and Manufacturing plants are biggest source of thermal pollution. These plants draw water from nearby source to keep machines cool and then release back to the source with higher temperature. When heated water returns to the river or ocean, the water temperature rises sharply. When oxygen levels are altered in the water, this can also degrade the quality and longevity of life in wildlife that lives underwater. This process can also wipe away streamside vegetation, which constantly depends on constant levels of oxygen and temperature. By altering these natural environments, industries are essentially helping decrease the quality of life for these marines based life forms and can ultimately destroy habitats if they are not controlled and careful about their practices.
2. Soil Erosion: Soil erosion is another major factor that causes thermal pollution. Consistent soil erosion causes water bodies to rise, making them more exposed to sunlight. The high temperature could prove fatal for aquatic biomes as it may give rise to anaerobic conditions.
3. 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.
4. Runoff from Paved Surfaces: Urban runoff discharged to surface waters from paved surfaces like roads and parking lots can make water warmer. During summer seasons, the pavement gets quite hot, which creates warm runoff that gets into the sewer systems and water bodies.
5. Natural Causes: Natural causes like volcanoes and geothermal activity under the oceans and seas can trigger warm lava to raise the temperature of water bodies. Lightening can also introduce massive amount of heat into the oceans. This means that the overall temperature of the water source will rise, having significant impacts on the environment.
Effects of Thermal Pollution
Among recognized scientists and scholars, there are generally two schools of thought when it comes to the effects of thermal pollution. Some lean on the side of the negatives of this pollution on marine ecosystems and how it is detrimental to positive environmental practices. However, some lean towards the side that without these industries operating the way they do, then some of the most basic parts of human life would be completely obsolete. Waste water would not be able to be properly maintained, we would have no industries that could produce the goods we need, and so on. The effects of thermal pollution on ecosystems, however, greatly outweigh the benefits that industries have by participating in the act.
1. Decrease in DO (Dissolved Oxygen) Levels: The warm temperature reduces the levels of DO (Dissolved Oxygen) in water. The warm water holds relatively less oxygen than cold water. The decrease in DO can create suffocation for plants and animals such as fish, amphibians and copepods, which may give rise to anaerobic conditions. Warmer water allows algae to flourish on surface of water and over the long term growing algae can decrease oxygen levels in the water.
2. Increase in Toxins: With the constant flow of high temperature discharge from industries, there is a huge increase in toxins that are being regurgitated into the natural body of water. These toxins may contain chemicals or radiation that may have harsh impact on the local ecology and make them susceptible to various diseases.
3. Loss of Biodiversity: A dent in the biological activity in the water may cause significant loss of biodiversity. Changes in the environment may cause certain species of organisms to shift their base to some other place while their could be significant number of species that may shift in because of warmer waters. Organisms that can adapt easily may have an advantage over organisms that are not used to the warmer temperatures.
4. Ecological Impact: A sudden thermal shock can result in mass killings of fish, insects, plants or amphibians. Hotter water may prove favorable for some species while it could be lethal for other species. Small water temperature increases the level of activity while higher temperature decreases the level of activity. Many aquatic species are sensitive to small temperature changes such as one degree Celsius that can cause significant changes in organism metabolism and other adverse cellular biology effects.
5. Affects Reproductive Systems: A significant halt in the reproduction of marine wildlife (although this may be true, reproduction can still occur between fish – but the likelihood of defects in newborns is significantly higher) can happen due to increasing temperatures as reproduction can happen with in certain range of temperature. Excessive temperature can cause the release of immature eggs or can prevent normal development of certain eggs.
6. Increases Metabolic Rate: Thermal pollution increases the metabolic rate of organisms as increasing enzyme activity occurs that causes organisms to consume more food than what is normally required, if their environment were not changed. It disrupts the stability of food chain and alter the balance of species composition.
7. Migration: The warm water can also cause particular species of organisms to migrate to suitable environment that would cater to its requirements for survival. This can result in loss for those species that depend on them for their daily food as their food chain is interrupted.
Above all else, the most important thing to consider is that the effects of thermal pollution greatly outweighs the human need for it to be done. Plants and industries have been able to find successful ways around thermal pollution, but many of them are not practicing it because it’s simply easier to work from the traditional model. If we want to promote the thriving environment that surrounds marine biology, then the attitude around thermal pollution needs to take a drastic turn. By being aware of the causes and effects, you can have a significant impact on how these plants choose to operate and you can opt to make change.
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Rinkesh
A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.
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