Data Bases • Custom Term Papers • Free Term Papers • Free Research Papers • Free Essays • Free Book Reports • Plagiarism? Links • Top 100 Term Paper Sites • Top 25 Essay Sites • Top 50 Essay Sites • Search 97,000 Papers @ DirectEssays.com • Search 101,000 Papers @ ExampleEssays.com • Search 90,000 Papers @ MegaEssays.com Free Essays • Term Paper Sites • Chuck III's Free Essays • Free College Essays • TermPaperSites.com • Free Essays • My Term Papers • Essay World • Planet Papers	Search Lots of Essays Back to Subjects - Physics Thermal pollution Thermal pollution Recently we've allowed our planet to begin overheating. With the introduction of CFC's and Carbon Dioxide into the atmosphere we've managed to raise the temperature of this vast resource. Even more ignorant is our failure to learn from our mistakes. Now, through thermal pollution (the introducton of waste heat into water), we've began destroying the womb of all life-the earth's vast water network. There are three major causes of thermal pollution. the use of water as a cooling agent The foremost cause being the use of water as a cooling agent in nuclear power plants and other industrial facilities. After the water has absorbed the excess heat of nuclear rods or other machinery it is returned to the environment (usually a river or lake) at 9 to 20 degrees warmer a temperature. More stringent regulations are imposeed in the U.S. , but this doesn't help much because most of the world's nuclear power plants are located in France and other European nations. Less obvious is how shoreline deforestation and soil erosion contribute to the problem. The soil erosion makes the water muddy, which in turn increases the light absorbed. Thus, the water temperature is raised. Deforestation of shorelines further contributes to the problem in two ways. First, it increases soil erosion. Secondly, it increases the amount of light that strikes the water. Both of which increase the water's temperature. By increasing the water's temperature we affect many other aspects of the ecosystem. Most importantly, the amount of oxygen dissolved in the water is decreased. Remember that fact for later. Also, the rates of photosynthesis and plant growth are increased. An increase in plant growth may seem to be a good thing at first. It isn't! More live plants means more dead plants later on. The pile up of dead plants leads to an increase of bacteria, bacteria that consume oxygen along with dead plants. Therein lies the problem. There is now less oxygen and a greater demand for it. The warmer water also increases the metabolic rate of fish, which leads to a sharp decrease in the life expectancy of aquatic insects. The fish have an increasing the need for oxygen due to a rise in their metabolism and population. With the lack of aquatic insects animals other than fish face a shortage of food. Also affected by thermal pollution is an animal's sensitivity to toxic waste, parasites, and other diseases. Water pollution involves the release into lakes, streams, rivers, and oceans of substances that become dissolved or suspended in the water or deposited upon the bottom and accumulate to the extent that they interfere with the functioning of aquatic ecosystems. It may also include the release of energy in the form of radioactivity or heat, as in the case of thermal pollution. Any body of water has the capacity to absorb, break down, or recycle introduced materials. Under normal circumstances, inorganic substances are widely dispersed and have little or no effect on life within the bodies of water into which they are released; organic materials are broken down by bacteria or other organisms and converted into a form in which they are useful to aquatic life. But, if the capacity of a body of water to dissolve, disperse, or recycle is exceeded, all additional substances or forms of energy become pollutants. Thus, thermal pollution, which is usually caused by the discharge of water that has been used as a coolant in fossil-fueled or nuclear-power plants, can favour a diversity of aquatic life in waters that would otherwise be too cold. In a warmer body of water, however, the addition of heat changes its characteristics and may make it less suited to species that are Pollution may begin as water moves through the air, if the air is polluted. Soil erosion adds silt as a pollutant. The use of chemical fertilizers, pesticides, or other materials on watershed lands is an additional factor contributing to water pollution. The runoff from septic tanks and the outflow of manures from livestock feedlots along the watershed are sources of organic pollutants. Industries located along waterways downstream contribute a number of chemical pollutants, some of which are toxic if present in any concentration. Finally, cities and towns contribute their loads of sewage and other urban wastes. Thus, a community far upstream in a watershed may receive relatively clean water, whereas one farther downstream receives a partly diluted mixture of urban, industrial, and rural wastes. The cost of cleaning and purifying this water for community use may be high, and the process may be only partially effective. To add to the problem, the cities and towns in the lower, or downstream, regions of the river basin contribute additional wastes that flow into estuaries, creating new pollution The output of industries, agriculture, and urban communities generally exceeds the biologic capacities of aquatic systems, causing waters to become choked with an excess of organic substances and organisms to be poisoned by toxic materials. When organic matter exceeds the capacity of those microorganisms in water that break it down and recycle it, the excess of nutrients in such matter encourages rapid growth, or blooms, of algae. When they die, the remains of the dead algae add further to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then attack the organic wastes, releasing gases such as methane and hydrogen sulfide, which are harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled body of water, a situation that has already occurred in such places as Lake Erie and the Baltic Sea and is a growing problem in freshwater lakes of Europe and North America. The process by which a lake or any other body of water changes from a clean, clear condition--with a relatively low concentration of dissolved nutrients and a balanced aquatic community--to a nutrient-rich, algae-filled body and thence to an oxygen-deficient, waste-filled condition is known as accelerated eutrophication. Bibliography: some web sites world book encyc Word Count: 1017
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