Saturday, August 6, 2011

What are the sources and effects of water pollutants?

 fungus. The oxygen to the sewage flora and fauna is given by the algae. There are other plants present in the sewage which provides the oxygen. There are many protozoa’s in the sewage which eat the bacteria. The algal component also supports the fungal and bacterial count. If there is decrease in the algal component the fungal and bacterial count also reduces. It affects the overall population except the blood and sludge worms. There is a foul odor from the sewage. It makes the sewage to look oily and water brown. A scum and sludge is formed from the organic waste and makes the water unfit for recreational and industrial purposes. The blooms are formed by the algae which decreases the level of oxygen. It adds more organic matter and cause the fouling of water. There are new detergents used these days which provide white and bright color to the clothes. These degrade slowly and aggregate making the water unfit for human consumption. There are phosphates present in them which allow the algae to grow and increase the overall organic content. There are many secondary pollutants which are formed by the process of anaerobiosis. It includes the hydrogen disulphide, ammonia and methane. The hydrogen disulphide has the ability to combine with the other elements and form a black color sulphide that can float.

There are certain pollutants which are present on the surface of land and they are passed into the water reservoirs during rains. The fertilizers are added to it to increase the yield of crop which is also passed to the water reservoirs. This fertilizer rich water goes into the streams and lakes leading to the eutrophication. It leads to the increase growth of blooms and aquatic plants. The plants which give rise to the bloom occur on the surface. The submerged plants do not produce the oxygen and cut of the light. The oxygen produced by the bloom goes into the atmosphere. The respiration of plants and animals during the night further decreases the level of oxygen. When the plant dies it increases the organic matter and it further decreases the level of oxygen. It causes the death of aquatic animals. It leads to the formation of unfit water for recreational and industrial processes. So, the excess of fertilizers must not be used. However, the small doses of fertilizers and manure must be used. They are helpful in the minimizing of surface run off. The ammonium sulphate and urea are considered the best fertilizers for the paddy. Some research institutes have recommended the use of urea along with the mud to form mud balls. They are situated below the soil surface. The ammonium sulphate also replaces the nitrates in tea plantations.

The unethical agriculture and forest practices lead to the soil erosion. It may also occur due to rain. It helps to make water muddy. It does not support the growth of plant as it cuts off the light. So, the animal population also gets affected. They also decrease the water ways as the mud and silt are deposited. The industrial wastes are moved into the water. They contain the mercury, lead, cadmium and other metals. The mercury is liberated as the result of combustion of coal. It is also produced by the smelting of ores and in the paper and paint industries. It is persistent and in the water it changes into the water soluble form which is known as the dimethyl. It has the ability to enter the food chain. It also causes the biological and ecological amplification. It kills the fishes and contaminates the rest of fauna. If the human beings feed on these fauna it leads to the condition known as a minamata disease which shows a crippling deformity which is accompanied by the numbness of lips along with the limbs, it affects the vision, hearing, taste, speech and ultimately leads to the death of an individual. The genetic changes are brought by the mercury also. It was supported by the Ramel in 1974. The lead occurs from the smelters, battery, industry, paint and the automobile exhausts. It causes mutations and may lead to the anemia, headache, discoloration in the gums, loss of muscle power, and irritation. The cadmium occurs from the industries, electroplating, phosphates and the pesticide industry. It also causes the biological amplification. It has the ability to accumulate inside the kidneys, liver and pancreas. It may cause the renal damage, hypertension, anemia, necrosis of the testes and an injury to the placenta. It can enter through the food chain and is entered via wheat and rice. It was supported by the Nath in 1986. The other metals involved are copper, zinc, nickel and titanium. They alter the function of enzymes. The liquid effluents are moved into the water which consists of the acids, bases and toxic substances. They kill the fish and other aquatic animals. They also cause an adverse effect on the human beings. They also involve many rivers like Gomati, Yamuna, Gang and Hooghly. They are present in the different parts of India. The continental shelf is a good source of oil. It is transported from one part of the country to other by the use of sea. The tankers which carry the fuel are washed after unloading in the sea. They are filled with the water. So, oil spills are very common in the sea. They occur near the ports and shore lines. During transportation accidents may happen which can spread the oil over few hundred kilometers. Nearly, 10 million tons of oil is spilled into the ocean per year. The other source of spillage of oil in the river is the refineries. They discharge in the form of effluents. There was a Barauni refinery which has an adverse effect on the flora and fauna of the river Ganges in the late 20th century. It leads to the spreading of oil on the surface of water which leads to the prevention of oxygenation. It also depletes the oxygen present in the water and leads to the degradation. It does not allow the growth of plankton and inhibits the photosynthetic activity of the other organisms in water. The decreased availability of food, oxygen leads to the destruction of animal life. The oil present on the surface of water may catch fire and can kill the organic matter present in water. The sea birds which are smeared with the oil get sick and die. The detergents which are used to clean the spill oil are also harmful and it was established in the Torrey Canyon accident along the British coast. There are hot bodies and effluents which may lead to the thermal pollution. The water which is warm contains less amount of oxygen as compared to the cold water. As the water is warmer the rate of decomposition is less. There are many animals which fail to divide and the green alga is replaced by the blue green algae. The trot fails to hatch the eggs at higher temperature and the salmon does not spawn. There are industries which are present in the coastal area which dump their wastes directly into the oceans and rivers. There are certain inland waters in some areas which are rich in the insecticides and pesticides. The sewage in the coastal cities does reach the sea directly. The products from the ship like garbage, sewage, detergents also pollute the water. Around one fourth of the people living in south Asia survive on this contaminated water and their products. There are people in the south pacific region which survive on sea food. They suffer from cholera and hepatitis frequently. There are certain segments of the people in Nigeria which use beaches as the place of toilet. The population becomes prone to water borne diseases along with the viruses and parasites. In the coastal waters the oxygen level becomes so dim that it is difficult for the flora and fauna to survive.

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