Essay, Pages 10 (2494 words)
More than 75 percent of the earth’s surface is covered by hydrosphere either as oceans or fresh water. Hydrosphere covers ground water also. Evaporation of water from oceans, cloud formation and precipitation are responsible for worldwide water supply through hydrological cycles. Water is essential to all life. Life was first originated in water.Water bodies include for example lakes, rivers, oceans, aquifers and groundwater. The contamination of these water bodies usually as a result of human activities is termed as water pollution.
Water pollution can also be understood as the presence of foreign organic, inorganic, biological or physical substances in the water bodies. It results when contaminants are released into the natural environment. An example of water pollution is when wastewater from the industries is inadequately released into the water bodies and which ultimately leads to the degradation of the aquatic bodies and also can cause health problems to people living nearby. They may use the same water for various activities like drinking or bathing or irrigation.
Surveys have claimed that water pollution is the leading worldwide cause of deaths and diseases. Water pollution adversely affects not only aquatic plants and animals but it also affects human beings and ecosystems.Some of the chemicals are useful for improving the quality of water, but if the same chemicals are used in higher concentration, then they degrade the quality and make the water unfit for various uses like in recreation, domestic and industries. On the other hand, there are some substances which degrade the quality of water even if used at lower concentrations.
There are various signs which can help in determining whether the water body is polluted or not. Some could be as follows:1. An unusual taste of water, basically a bad taste 2. Unusual and offensive odors from the water bodies which are very different from the very usual odors of water bodies3. Decrease in number of aquatic animals or unchecked growth of weeds which has been caused by the contamination of water bodies due to the inadequate release of harmful chemicals or toxins which are generally released from the industries with fresh water4. Unusual and inadequate substances being present in the water bodies like glass, plastic, aluminum, steel, etc.Causes of water pollution:Some of the major causes of water pollution are as follows:a. Sewage and waste water: The waste from households, sewage and garbage, agricultural lands and factories is released into the lakes and rivers. Sewage consists of the excreta (faeces and nitrogenous wastes) of animals. It is rich in organic matter and nitrogen compounds. These contain harmful chemicals which are poisonous for the aquatic animals and plants and also for inadequate to be used for various activities like bathing, drinking, etc.b. Dumping: Various products like glass, plastic or any sort of metal take different amount of time to degrade and again affect the aquatic plants and animals. And thus, dumping of such products causes huge problems.c. Industrial waste: Industrial waste contains a lot of pollutants which are extremely harmful to the environment and also to the people. The industries that cause pollution are printing, electroplating, soap manufacture, food products, rubber and plastics, chemicals, textiles, steel, sugar factories, glass manufacture etc. Discharging the industrial waste thus result in polluting the water bodies.d. Oil pollution: The larger water bodies get polluted due to the spilling of oil from the ships and tankers. The oil is thick and thus remains insoluble in water thus, contaminating the water bodies.e. Acid rain: Acid rain causes water pollution by air pollution. When the acidic particles present in the atmosphere mix with water vapor, it causes acid rain. f. Global warming: Global warming causes an increase in the temperature of water. Thereby increasing the metabolic rate and oxygen consumption of microorganisms. Such an increase in the water temperature results in the death of aquatic plants and animals, which is the contamination of water bodies.g. Fertilizer Pollution: Adding large amount of inorganic fertilizers to crop fields result in the nutrient enrichment of streams, rivers and lakes. A major part of fertilizer becomes available for excessive algal growth. This is truer for nitrogenous fertilizers (which are readily soluble) than phosphate. Nitrate in agricultural drainage contaminate drinking water. Nitrite poisoning occurs in infants and farm animals by ingesting water or food containing high level of nitrite. Bacteria normally found in the water are able to convert nitrate ions fertilizers and organic wastes to nitrite. The concentration of nitrates and nitrites are reduced naturally by the action of the denitrifying bacteria in water and soil.h. Radioactive Wastes: Many radioactive isotopes escape to water reservoirs, rivers and seas from nuclear power reactors. They enter the food chain in ecosystem. These wastes may accumulate in the bodies of aquatic animals like fishes causing harm to them as well as animals which eat them.The water pollutants also cause effects on different parameters associated with water bodies. We are well aware of the fact that water is colorless. The colorless pure water travels through nature and becomes by the addition of various impurities. The contaminated water also tastes bitter and saline again due to the impurities present in the water bodies. The unpleasant taste and odor is aesthetically unacceptable even though it may not pose any serious threat to health.Examples of water pollution:Collecting information of the facts regarding water pollution in India:(i) The Ganga Basin:The Ganga basin is the largest river basin in India, with geographical area of 9,00,000 sq. km. and a stretch of 2525 km. It may be compared to the river Nile (6,650 km) and Amazon (6500 km) but it carries the heaviest sediment load (2.4 billion metric tonnes per year).This huge sediment load is due to (a) high erosion rate of Himalayan rocks (birthplace of Ganga), (b) large size of drainage basin with steep angle of elevation in the Himalayan region, (c) numerous tributaries transporting soil to the main stream, (d) dense population in most part of the basin with their intense agricultural practices.Each year about 1,15,000 tonnes of fertilizers are washed away with agricultural waste water into the Ganga-they include 88,600 tons of N, 17,000 tons of P and 9,200 tonnes of K. The water holding capacity of the Ganga and its tributaries are getting reduced due to high rate of siltation, leading to devastating floods at regular intervals during the current century.The Ganga basin in the home of about 37% of the total population of the country. About 84% of the people live in rural areas while 16% are distributed in 692 cities and towns of the basin.The overall density of population is 300 persons per sq. km., compared to 200 for the whole of India. The highest density of rural population is found in the lower Gangetic plain e.g. in W.B. with 475 persons per sq. km. It has increased to 20,000 persons per sq. km in the industrial belts of Hooghly and 24 paragraph.The high intensity of cultivation in the rural sectors, high population density and high concentration of factories in towns and cities account for generation of huge amounts of organic and inorganic pollutants in the basin most of which finally find their way into the main stream.Taking the basin as a whole, the average amount of BOD load comes to 24 g. per person per day in the rural sector and 64 g. per person per day in the urban.Monitoring of the water quality in terms of the standard parameters reveals that the upper stretch (Rishikesh upstream of Kanpur) is the best clean range (D.O. 8-9; B .O.D. < 2) while Kanpur ” 50 km. downstream (45 tanneries, 10 textile mills, 2 jute mills and many chemical and pharmaceutical units) is polluted (D.O. 4-6; B.O.D. 10-50); Varanasi is the second polluted zone (D.O. 8-9; B.O.D. 4-24) while Hoogly near Calcutta is the most polluted zone (D.O. 4-7; B.O.D. 4-50).The Hooghly river near Calcutta is contaminated with waste effluents from about 150 industries (including 87 jute mills, 12 textile mills, 7 tanneies, 5 paper mills and 4 distilleries) as well as domestic sewage from 360 out falls on both sides of the river.Hooghly estuarine water does not show any significant pollution level of inorganic but has considerable organics (pesticides) while the sediment is quite rich in toxic metal levels (Diamond Harbour, Cd 6.6, Cr 26.5, Pb 516 mg/kg) and organochlorine pesticides (B.H.C. 25-125 ppb; D.D.T. 0.25-4.5 ppb).This has adverse impact on the health status of the population residing in the estuarine areas. The population showed higher levels of heavy metals and pesticides in their hair (cd 3-5 ppm, Cr 2 ppm, Pb 50 ppm) respectively.(ii) The Damodar Valley: Durgapur Asansol Profile:The river Damodar originates from Chhotanagpur plateau in Bihar, crosses about 500 km through Bihar and W. Bengal and joins the Hooghly river opposite Falta at a distance of 58 km. South of Calcutta. The Damodar valley from Durgapur to Asansol forms the largest industrial complex in W. Bengal and the eastern region. This area is known as the River of India.Its high record of pollution is due to indiscriminate discharge of huge quantities of pollutants generated by industries, mining and mineral processing industries which are concentrated on both sides or in the proximity of the river.Besides mining, transport and trade, there are some 50 large, 100 medium and 200 small industries units extending from Giddi in Hibar to Durgapur in W.B. along the mid-river stretch of 300 km. The river segments upstream of Giddi and downstream of Bardhaman are much less significant in terms of water pollution.Indian Iron and Steel Co., Cycle Corporation of India, Carew and Co., Bengal Paper Mill and Durgapur steel plant discharge various types of pollutant (some are non-degradable and persistent) which accumulate in Durgapur barrage water.The concentration of these toxic pollutants in barrage water is above the permissible limits for surface water. Thus tannin ” lignin (0.9 ppm), NH3 (0.5-6 ppm), phenol (0.002 ppm) are found in barrage water, exceeding their respective tolerance limits.It should be noted that the barrage water remains the sources of domestic water supply for Durgapur city. The conventional water treatment methods fail to remove organic matter, phenol and toxic metals so that these find their way into domestic water supply.Furthermore, in the process of water treatment, chlorination enhances toxicity of water by formation of toxic chloramines and chlorophenols through reactions with NH3 and phenol respectively. Thus the residents of the city are constantly exposed to these toxic pollutants in their domestic water supply.On the other hand, the downstream river (beyond Durgapur barrage) is contaminated by Tamla Nalah and HFC drain. The Tamla Nalah delivers a heavy pollution load to the river-phenol (0.02 ” 2.0 ppm), NH3 (10-40 ppm), C.O.D. (80-350 mg/I), sulphide (1.5-15 ppm), Hg (0.01-0.05 ppm) which are deposited in the river bed. The sediments containing these parameters in 10 to 100 fold excess act as storehouse of these pollutants and supply these pollutants continuously by leaching action throughout the river course in the region.People in the industrial belt are constantly exposed to health hazards due to synergic effect of water pollution and industrial air pollution. The incidences of liver diseases such as hepatitis, jaundice, dysentery etc. and respiratory diseases such as bronchitis, bronchial asthma, pulmonary tuberculosis etc. are quite high in the INDUSTRIAL BELT.Effects of water pollutionWater is a basic necessity. It is required by all the living organisms for performing various functions. It also is a habitat for many organisms. Humans use water for drinking, bathing, washing, irrigation, navigation, recreation, construction work, power generation and waste disposal.A different level of purity is required for different types of water and the highest level of purity is required for water used for drinking. Presence of pollutants brings many physical and chemical changes in the true state of water.Death of aquatic animalsThe main problem caused by water pollution is that it kills organisms that depend on these water bodies. Dead fish, crabs, birds and sea gulls, dolphins, and many other animals often wind up on beaches, killed by pollutants in their habitat.Disruption of food-chainsPollution disrupts the natural food chain as well. Pollutants such as lead and cadmium are eaten by tiny animals. Later, these animals are consumed by fish and shellfish, and the food chain continues to be disrupted at all higher levels.DiseasesEventually, humans are affected by this process as well. People can get diseases by eating seafood that has been poisoned. In many poor nations, there is always outbreak of cholera and diseases as a result of poor drinking water treatment from contaminated waters.Destruction of ecosystemsEcosystems (the interaction of living things in a place, depending on each other for life) can be severely changed or destroyed by water pollution. Controlling and managing water pollution:Clean water is essential for healthy environment to support life systems on this planet. The task of delicately balancing the ratio of available and exploitable water resources and sustaining their quality is most relevant in India where rainfall distribution is uneven and confined to 3-4 months in a year.1. Never throw rubbish away anyhow. Always look for the correct waste bin. If there is none around, please take it home and put it in your trash can. This includes places like the beach, riverside and water bodies.2. Use water wisely. Do not keep the tap running when not in use. Also, you can reduce the amount of water you use in washing and bathing. If we all do this, we can significantly prevent water shortages and reduce the amount of dirty water that needs treatment.3. Do not throw chemicals, oils, paints and medicines down the sink drain, or the toilet. In many cities, your local environment office can help with the disposal of medicines and chemicals. Check with your local authorities if there is a chemical disposal plan for local residents.4. Buy more environmentally safe cleaning liquids for use at home and other public places. They are less dangerous to the environment.5. If you use chemicals and pesticides for your gardens and farms, be mindful not to overuse pesticides and fertilizers. This will reduce runoffs of the chemical into nearby water sources. Start looking at options of composting and using organic manure instead.6. If you live close to a water body, try to plant lots of trees and flowers around your home, so that when it rains, chemicals from your home does not easily drain into the water.Life is ultimately about choices and so is pollution. We can live with sewage-strewn beaches, dead rivers, and fish that are too poisonous to eat. Or we can work together to keep the environment clean so the plants, animals, and people who depend on it remain healthy. We can take community action too, by helping out on beach cleans or litter picks to keep our rivers and seas that little bit cleaner. And we can take action as countries and continents to pass laws that will make pollution harder and the world less polluted. Working together, we can make pollution less of a problem and the world a better place.