Water Temperature Of The Water example essay topic

What is thermal pollution? One of the most serious ways that humans change the temperature of waters is through thermal pollution. The raising of the air or water temperature by artificial means is called thermal pollution. Thermally polluted water often undergoes biological changes that make it less valuable for drinking, recreational, habitat and industrial uses. What causes Thermal pollution? o Industries, such as nuclear power plants, may cause thermal pollution by discharging water used to cool machinery. The water is taken from the water to cool down the machines and when it is too warm to cool them down anymore, it is returned to the water.

This raises the temperature of the water causing thermal pollution. o Stormwater running off warmed surfaces, such as streets, sidewalks and parking lots causes thermal pollution. When the warmed water goes down the stormwater drain, it is released directly into the stream or dam causing thermal pollution. o Trees and other plants are very important to water temperature. Vegetation naturally occurs along streams, rivers and lakes. Their presence is very important as they shade the water to help keep it cool. If the trees are not there, there is no shade.

Tree roots also serve to hold soil in place. Without the trees, soil erosion adds its impact to thermal pollution. One of the side effects of soil entering streams, rivers and lakes is that it makes the water cloudy. Cloudy water absorbs more sunlight, which heats up the water. Another thermal impact of soil is that eroded soil fills in stream beds causing the channels to widen, become shallower and slow the current. Shallower channels are more easily heated up by the sun than deeper water.

Specific heat Specific heat is the amount of heat needed to raise the temperature of 1 gram of a substance by 1 degree celcius. The specific heats of a few common substances are shown below: Substance Formula Specific Heat (Jg K) Water (L) H O 4.184 Ethanol CH CH OH 2.46 Ethylene Glycol (Anti-freeze) (CH OH) 2.42 Carbon tetrachloride CCl 0.681 Oxygen Solubility An adequate supply of dissolved oxygen gas is essential for the survival of aquatic organisms. When the water temperature of the water is raised, the amount of oxygen dissolved in the water decreases. From the following graph we can see the rate oxygen is dissolved at in specific heats of water. Effect of heated water on aquatic organisms As water temperature rises, the rate of photosynthesis and plant growth also increases. More plants grow and die.

As plants die, they are decomposed by bacteria that consume oxygen. Therefore, when the rate of photosynthesis is increased, the need for oxygen in the water increases. The metabolic rate of organisms also rises with increasing water temperatures, resulting in an even greater oxygen demand. The life cycles of aquatic insects tend to speed up in warm water. Animals that feed on these insects can be negatively affected. For example, the stage of the insects' life cycle may not be in sync with the needs of birds that depend on insects emerging at specific times.

Most aquatic organisms have adapted to survive within a range of water temperatures. Some species prefer cooler water, such as trout, while others thrive under warmer conditions, such as carp. As the temperature of a river increases, cool water species will be replaced by warm water species. Few species can tolerate extremes of heat or cold. Temperature also affects aquatic life's sensitivity to toxic wastes, parasites, and disease.

For example, thermal pollution may cause fish to become more vulnerable to disease, either due to the stress of rising water temperatures or the resulting decrease in dissolved oxygen. Effects of thermal pollution The effects of thermal pollution are of two types; thermal shock and thermal enrichment. Change in water temperature above its normal level, due to hot wastewater, can harm fish and organisms adapted to a particular water temperature regime from thermal shock. For example, warmer water may interfere with fish growth, reproduction, and food supply. In some cases, fish may be killed due to the sudden and rapid rise in temperature. However, some argue that heated water may be used for beneficial purposes, calling it thermal enrichment.

For example warm water from power plants may be used for irrigation to extend plant growing season in frost-prone areas, speed the growth of fish and shellfish for commercial production, melt snow on sidewalks and desalinate ocean water. Unfortunately, the harmful effects of thermal pollution seem to outweigh the beneficial effects. Ways to control.