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WATER POLLUTION. WATER. Water is a ubiquitous chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life.
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WATER • Water is a ubiquitous chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life. • In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. • Water on Earth moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land, evaporation and transpiration contribute to the precipitation over land.
USES OF WATER • Water is used for drinking, washing , bathing , etc. • It is also used for irrigation purpose. • A lot of water is used to make food. • Almost every food contains water
SCARCE OF DRINKING WATER • This natural resource is becoming scarcer in certain places, and its availability is a major social and economic concern. Currently, about a billion people around the world routinely drink unhealthy water. • Poor water quality and bad sanitation are deadly; some five million deaths a year are caused by polluted drinking water. The World Health Organization estimates that safe water could prevent 1.4 million child deaths from diarrhea each year. • It is, rather, the distribution of potable and irrigation water which is scarce, rather than the actual amount of it that exists on the earth.
WATER POLLUTION • Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, groundwater). • Water pollution affects plants and organisms living in these bodies of water and in almost all cases the effect is damaging either to individual species and populations, but also to the natural biological communities. • Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.
SOURCES OF WATER POLLUTION. 1) INDUSTRY • Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment. • Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans. • Pollutants from industrial sources include: • Asbestos – This pollutant is a serious health hazard . Asbestos fibres can be inhaled and cause illnesses such as asbestosis, lung cancer, intestinal cancer and liver cancer. • Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
2) OIL POLLUTION IN WATER • Oceans are polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping. • Oil spills make up about 12% of the oil that enters the ocean. The rest come from shipping travel, drains and dumping. • An oil spill from a tanker is a severe problem because there is such a huge quantity of oil being spilt into one place. • Oil cannot dissolve in water and forms a thick sludge in the water. This suffocates fish, gets caught in the feathers of marine birds stopping them from flying and blocks light from photosynthetic aquatic plants.
3) RADIO ACTIVE WASTE • Nuclear waste is produced from industrial, medical and scientific processes that use radioactive material. Nuclear waste can have deterimental effects on marine habitats. Nuclear waste comes from a number of sources: • Operations conducted by nuclear power stations produce radioactive waste. Nuclear-fuel reprocessing plants in northern Europe are the biggest sources of man-made nuclear waste in the surrounding ocean. Radioactive traces from these plants have been found as far away as Greenland. • Mining and refining of uranium and thorium are also causes of marine nuclear waste.
4.Mining and Agricultural Wastes Mines, especially gold and coal mines, are responsible for large quantities of acid water. Agricultural pesticides, fertilizers and herbicides may wash into rivers and stagnant water bodies. 5. Sewage Disposal and Domestic Wastes Sewage as well as domestic and farm wastes were often allowed to pollute rivers and dams. 6.Human activities: Human activities such as bathing , washing clothes etc in towns and villages lead to water pollution 7.Customs and Traditions: Disposal of dead bodies and immersion of idols of gods and goddess into water bodies during various festivals in India degrade the quality of water.Plaster of Paris which is used generally used to make the idols contain gypsum , sulphur and magnesium and idols are decorated using chemical paints that contain magnesium , cadimiumand lead. All these increase the acidity of water and concentration of heavy metals in it. Such water pollution can damage the ecosystem by killing aquatic plants and organism and other living creatures dependent on water.
Garbage Polluted Stream Water Pollution by Mining Water Pollution by Slums
Water Quality Standards: • Water is usually colourless, tasteless and odourless in its pure form. Due to addition of a number of substances due to natural or artificial reasons it loses its pure character and quality. Therefore several impurities are always associated with it. • Water quality standards are the foundation of the water quality based pollution control programs mandated by the clean water act. • Water quality standards define the goals for a water body by designating its uses, setting criteria to protect those uses and establishing provisions such as anti degradation policies to protect water bodies from pollutants.
Impurities in water • Physical Impurities: These impurities are mainly caused due to soil erosion including soil particles, pollens microorganisms etc. Generally these impurities are separated by filtration. • Minerals Impurities: These are mainly the minerals present in soil which get dissolved in ground water or surface water. These are also known as total dissolved solid (TDS) .In many parts of India water gets contaminated due to the presence of fluorides , arsenic and iron which causes fatal diseases. • Organic Impurities: Surface water is subjected to these organic impurities comprising both plant and animal residuals and microorganisms, which are found on the surface of earth. Fertilizers and pesticides are the chief organic contaminants found in water.
Mandatory Requirements for water testing • Testing water samples of ground water is a mandatory requirement to keep a check on its quality. Most of the authorities which supply drinking water are equipped with water testing facilities. The strict enforcement of pollution control laws has resulted in an increase in demand for lab facilities for the proper testing of water quality standards. • There are many private agencies which provide wide spectrum of water testing services. The results of labs. Accredited Board for testing and calibration laboratories are accepted by the Pollution Control Board and other government authorities.
EFFECTS OF WATER POLLUTION • Virtually all types of water pollution are harmful to the health of humans and animals. Water pollution may not damage our health immediately but can be harmful after long term exposure. Different forms of pollutants affect the health of animals in different ways: • Heavy metals from industrial processes can accumulate in nearby lakes and rivers. These are toxic to marine life such as fish and shellfish, and subsequently to the humans who eat them. • Industrial waste often contains many toxic compounds that damage the health of aquatic animals and those who eat them. Some of the toxins in industrial waste may only have a mild effect whereas other can be fatal. They can cause immune suppression, acute poisoning. • Microbial pollutants from sewage often result in infectious diseases that infect aquatic life and terrestrial life through drinking water. Microbial water pollution is a major problem in the developing world, with diseases such as cholera and typhoid fever being the primary cause of infant mortality.
EFFECTS OF WATER POLLUTION---- • Organic matter and nutrients causes an increase in aerobic algae and depletes oxygen from the water column. This causes the suffocation of fish and other aquatic organisms. • Sulphate particles from acid rain can cause harm to the health of marine life in the rivers and lakes it contaminates, and can result in mortality. • Suspended particles in freshwater reduces the quality of drinking water for humans and the aquatic environment for marine life. Suspended particles can often reduce the amount of sunlight penetrating the water, disrupting the growth of photosynthetic plants and micro-organisms.
Definition • Eutrophication is a process whereby water bodies, such as lakes, or slow-moving streams receive excess nutrients that stimulate excessive plant growth (algae, periphyton attached algae, and nuisance plants weeds). • This enhanced plant growth, often called an algal bloom, reduces dissolved oxygen in the water when dead plant material decomposes and can cause other organisms to die. Nutrients can come from many sources, such as fertilizers applied to agricultural fields, golf courses, and lawns; deposition of nitrogen from the atmosphere; erosion of soil containing nutrients; and sewage treatment plant discharges. Water with a low concentration of dissolved oxygen is called hypoxic.
Eutrophication is a natural process! However, humans in their everyday activities can exacerbate the process: Point sources (can locate the cause) • Sewage treatment plant discharges • Storm sewer discharges • Industrial discharges Non-point sources (can’t locate the cause, it’s everywhere) • Atmospheric deposition • Agricultural runoff (fertilizer, soil erosion) • Septic systems
Eutrophication process in 6 stages ADDITION OF NITRATES GROWTH OF PLANTS DEATH OF PLANTS GROWTH OF BACTERIA LACK OF OXYGEN SUFFOCATION
Lake Biwa, the largest lake in Japan during summer time showing overgrowth of aquatic plants.
Impact of Eutrophication • Include death of aerobic organisms, • increased turbidity, • reduction in length of food chains and loss of species diversity.
Biomagnification • Definition: • Biomagnification, also known as bioamplification, or biological magnification is the increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain
Effects of Water Pollution on Animals: • The organisms that live in aquatic habitats are directly affected by water pollution. The presence of harmful chemicals and pollutants in water makes the survival of aquatic organisms extremely difficult. Owing to the increasing amounts of pollutants in water a large no. of known and unknown aquatic plant and animal species become extinct. • Drinking polluted water causes the toxins present in the water to enter the body of the organisms , this poisoning may lead to serious health disorders and may even cause death.
Control of Water Pollution • Judicious use of agrochemicals like pesticides and fertilizers which will reduce surface run off .Avoid their usaage of these on slope lands. • Use of nitrogen fixing plants to supplement the use of fertilizers. • Adopting integrated pest management to reduce reliance on pesticides. • Prevent run off manure. Divert such run off to basin for settlement .
Control of Water Pollution • Separate drainage of sewage and rain water should be provided to prevent overflow of sewage with rain water. • Planting trees would reduce pollution by sediments and will also prevent soil erosion. • Waste water should be treated by primary and secondary treatment to reduce BOD,COD levels upto permissible levels of discharge. • Industrial effluents and wastes must be treated in order to reduce their toxity. • Non biodegradable waste materials such as plastics should not be dumped in water bodies .These not only increase the levels of toxins in water but also choke the aquatic organisms to death.
Control of Water Pollution • Human activities such as bathing and washing in the rivers , ponds and lakes , washing animals, immersing of idols must be stopped.
The contamination of the marine environment due to the presence of various undesirable materials that have been added directly or indirectly by humans is known as marine pollution. This pollution has adversely affects biological resources and human health.
Marine pollution: Another definition The introduction by man of substances or energy into the marine environment, which results in harm to marine life, hazards to human health, hindrance to marine activities, including fishing and other legitimate uses of the sea, impairment of quality for use of sea water and reduction of amenities.
Causes of Marine Pollution: • Oil and petroleum spillage: It includes leakage of oil from oil tankers, accidental discharge in the sea. South Africa is greatly threatened as it lies on one of the busiest shipping routes.
Toxic Chemicals: Industrial wastes containing toxic chemicals and heavy metals pollute marine ecosystem and hence are considered to be the most lethal pollutants causing marine pollution. A part from heavy metals substances such as petrol and grease, oil, pesticides, herbicides and solvents on marine ecosystem
Hazardous Wastes: Wastes discharged through nuclear testing, nuclear power plants, defence explosions are categorised as hazardous wastes. These substances poison the ecosystem and cause a serious form of marine pollution
Raw Sewage: Oceans receive huge amount of sewage from costal cities all over the World. Of over 60 licensed pipe lines that discharge effluents along the South African coast, about 66 million litres per day, half discharge industrial wastes and mixed effluents.
