EVS- WATER POLLUTION PRESENTATION

WATERPOLLUTION

BY: Tejaswi (D-29) Kiriti (D-36) Sandli (D-34) Saloni (D-12 )

Definition

• What is water pollution?

Contaminants

• What are the sources and causes of it?

Index

Types and measurement of water pollution

• What are the different types of water pollutions?

IMPACTS OF WATER POLLUTION ON THE ENVIRONMENT

• What are the Impacts and effects of water pollution on the environment and how does it affect people?

CONTROL AND REDUCTION MEASURES

Water Pollution

Water pollution (or aquatic pollution) is the contamination of water bodies, usually due to human activities, that negatively affect their uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses". Water is typically referred to as polluted when it is impaired by anthropogenic contaminants. Due to these contaminants, it either no longer supports a certain human use, such as drinking water, or undergoes a marked shift in its ability to support its biotic communities, such as fish.

CONTAMINANTS

There are various classifications of water pollution. The two chief sources of water pollution can be seen as Point and Non-Point. Point Sources refer to the pollutants that belong to a single source. An example of this would be emissions from factories into the water. Non Point Sources on the other hand means pollutants emitted from multiple sources. Contaminated water after rains that has travelled through several regions may also be considered as a Non-point source of pollution.

• PoinT Sources
• Non-Point sources

MAJOR CAUSES OF WATER POLLUTION

• Sewage leakages
• High population density
• oil spillage
• Industrial waste dumped into our waters
• Pollution of groundwater through drilling activities
• Flooding during the rainy season carries waste deposits into our waters.
• Building lavatories and visionaries over running water or even the sea as it the practice in some riverine areas.

• Radioisotopes
• Heavy metal Combustion

• Toxic waste disposal at sea
• Mineral processing plant (e.g. coal production)
• Eroded sediments
• Deforestation
• Mining
• Littering
• Pesticides
• herbicides and fertilizers
• Failing septic system
• Household chemicals
• Animal wastes.

MAJOR SOURCES OF WATER POLLUTION

1) Industrial waste Industries produce huge amounts of waste which contains toxic chemicals and pollutants which can cause air pollution and damage to us and our environment. They contain pollutants such as lead, mercury, sulphur, asbestos, nitrates and many other harmful chemicals. Many industries do not have proper waste management systems and drain the waste into the freshwater which goes into rivers, canals and later into the sea. The toxic chemicals have the capability to change the colour of water and increase the number of minerals, also known as Eutrophication, which changes the temperature of the water and poses a serious hazard to water organisms. 2) Sewage and wastewater The sewage and waste water that is produced by each household is chemically treated and released into the sea with fresh water. The sewage water carries harmful bacteria and chemicals that can cause serious health problems. Pathogens are known as common water pollutants. The sewers of cities house several pathogens and thereby diseases. Microorganisms in water are known to be causes of some very deadly diseases and become the breeding grounds for other creatures that act like carriers. These carriers inflict these diseases via various forms of contact with an individual. A very common example of this process would be Malaria. 3) Mining activities Mining is the process of crushing the rock and extracting coal and other minerals from underground. These elements when extracted in the raw form contain harmful chemicals and can increase the amount of toxic elements when mixed up with water which may result in health problems. Mining activities emit several metal waste and sulphides from the rocks and are harmful to the water.

CAUSES OF WATER POLLUTION

POINT AND NON-POINT SOURCES

4)Marine dumping: The garbage produced by each household in the form of paper, aluminum, rubber, glass, plastic, and food is collected and deposited into the sea in some countries. These items take from 2 weeks to 200 years to decompose. When such items enter the sea, they not only cause water pollution but also harm animals in the sea. 5) Accidental Oil leakage: Oil spills pose a huge concern as a large amount of oil enters into the sea and does not dissolve with water; thereby opening problems for local marine wildlife such as fish, birds and sea otters. For e.g.: a ship carrying a large quantity of oil may spill oil if met with an accident and can cause varying damage to species in the ocean depending on the number of oil spills, the size of the ocean, and the toxicity of pollutants. 6) Burning of fossil fuels: Fossil fuels like coal and oil when burnt produce substantial amount of ash in the atmosphere. The particles which contain toxic chemicals when mixed with water vapor result in acid rain. Also, carbon dioxide is released from the burning of fossil fuels which result in global warming. 7) Chemical fertilizers and pesticides: Chemical fertilizers and pesticides are used by farmers to protect crops from insects and bacteria. They are useful for the plant's growth. However, when these chemicals are mixed up with water produce harmful to plants and animals. Also, when it rains, the chemicals mix up with rainwater and flow down into rivers and canals which pose serious damage for aquatic animals 8) Leakage from sewer lines: A small leakage from the sewer lines can contaminate the underground water and make it unfit for people to drink. Also, when not repaired on time, the leaking water can come onto the surface and become a breeding ground for insects and mosquitoes. 9) Global warming: An increase in the earth’s temperature due to the greenhouse effect results in global warming. It increases the water temperature and results in the death of aquatic animals and marine species which later results in water pollution.

10) Radioactive waste: Nuclear energy is produced using nuclear fission or fusion. The element that is used in the production of nuclear energy is Uranium which is a highly toxic chemical. The nuclear waste that is produced by radioactive material needs to be disposed of to prevent any nuclear accidents. Nuclear waste can have serious environmental hazards if not disposed of properly. A few major accidents have already taken place in Russia and Japan. 11) Leakage from the landfills: Landfills are nothing but a huge pile of garbage that produces awful smell and can be seen across the city. When it rains, the landfills may leak and the leaking landfills can pollute the underground water with a large variety of contaminants. 12) Animal waste: The waste produce produced by animals is washed away into the rivers when it rains. It gets mixed up with other harmful chemicals and causes various waterborne diseases like cholera, diarrhoea, jaundice, dysentery and typhoid. 13) Underground storage leakage: Transportation of coal and other petroleum products through underground pipes is well known. Accidental leakage may happen anytime and may cause damage to the environment and result in soil erosion.

WATER POLLUTION LEVELS IN VARIOUS COUNTRIES

A picture DEPICTING water pollution levels in various regions around the world.

TYPES OF WATER POLLUTION

The second most prevalent kind of pollution after contaminated air, water pollution afflicts our rivers, lakes, reservoirs, groundwater and aquifers – not to mention the seas and oceans which cover the majority of our planet. However, not all kinds of water pollution come from the same source. Here’s a quick rundown of the different types of water pollution currently compromising the quality of H0 all over the globe.

1) Chemical pollution The most common type of water pollution, chemicals can infiltrate both underground water sources and those sitting on the Earth’s surface. As an integral component of the agricultural industry, it’s unsurprising that much of chemical contamination comes from the pesticides and fungicides used in farming, but metals and solvents from industrial sites are also leading contributors. 2) Groundwater pollution As mentioned above, agriculture is a key source of water pollution, especially groundwater. Fertilisers and pesticides applied to crops can seep into the ground and contaminate underwater rivers and waterbeds, thus compromising the quality of wells, boreholes and other places from which groundwater is extracted for human use. 3) Microbiological pollution Unlike most others on this list, microbiological pollution is a naturally occurring form of water contamination. Microorganisms such as bacteria, protozoa and viruses can infiltrate water supplies, causing diseases such as bilharzia and cholera. Humans are most susceptible to this kind of pollution in places where adequate water treatment systems are not yet in place.

4) Nutrient pollution While they’re vital for underwater flora and fauna to flourish, an excess of nutrients can upset the delicate imbalance of water-based ecosystems. Fertilisers contain a high concentration of nutrients which, if they contaminate rivers, lakes and coastal areas, can cause algal blooming that can block out sunlight and inhibit the growth of other organisms. 5) Oxygen-depletion pollution Another consequence of algal blooms is their consumption of oxygen supplies. This means that those species which depend upon oxygen to survive are killed off, while anaerobic ones thrive. Some anaerobic microorganisms are capable of producing ammonia, sulphides and other harmful toxins, which can make the water even more dangerous to animals (and humans, too). 6) Surface water pollution Referring to all water sources above ground, such as rivers, lakes, seas and oceans, surface water pollution can occur both naturally, accidentally and intentionally. For example, monitoring has an all-important role in natural flood management, which can lead to poor water quality, while accidental oil spills and negligent industries emptying waste into water bodies are also key contributors. 7) Suspended matter Improperly discarded waste, such as fragments of plastic, rubber or other manmade materials, can find themselves in water sources and persist for a long time. Because they are too robust to dissolve in the water and too big to mix effectively with the molecules, they simply float on their surface and prevent oxygen and sunlight from penetrating below.

Biological oxygen demand: basically involves the measurement of dissolved oxygen (DO) utilized by the microorganisms for the biochemical oxidation of organic matter. The demand for oxygen and the process of oxidation depends on the type and quantity of organic matter, temperature and type of the organism used.

MEASUREMENT OF WATER POLLUTION

BIOLOGICAL OXYGEN DEMAND

Water Pollution can be measured through various broad categories. It can be defined into three major categories:

Chemical oxygen demand: refers to the oxygen equivalents of organic matter that can be oxidized by using strong chemical oxidizing agents. Usually, potassium dichromate in the presence of a catalyst, in acidic medium is employed for this purpose.

CHEMICAL OXYGEN DEMAND

Physical: It includes the measurement of water temperature, turbidity, and total suspended particle in the water sample.

PHYSICAL MEASUREMENT

IMPACT OF WATER POLLUTION

EFFECTS OF WATER POLLUTION

Water pollution has a duel effect on nature. It has negative effects on the living and also on the environment. The effects of pollution on human beings and aquatic communities are many and varied. Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrhoea every day and so many other countries too. Nearly 500 million Chinese lack access to safe drinking water. Definitely, with all these, we can expect that there is going to be a reduction in productivity. Biomass and diversity of communities are to be expected when a large number of toxic materials are released into the streams, lakes and coastal waters in the ocean. Much of aquatic pollution involves sewage in which organic waste predominates. This waste can increase secondary productivity while altering the character of the aquatic community. Most fishes especially the species desired as food by man are among the sensitive species that disappear with the least intense pollution. Water pollution leads to damage to human health. Disease-carrying agents such as bacteria and viruses are carried into the surface and groundwater. Drinking water is affected and health hazards result. Plants' nutrients including nitrogen, phosphorus and other substances that support the growth of aquatic plant life could be in excess causing algal gloom and excessive weed growth. This makes water have an odour, taste and sometimes colour. Ultimately, the ecological balance of a body of water is altered. Sulphur dioxide and nitrogen oxides cause acid rain which lowers the pH value of soil and the emission of carbon dioxide cause ocean acidification, the ongoing decrease in the PH of the Earth’s Oceans as CO2 becomes dissolved.

Control measures for water pollution 1. Administration of water pollution control should be in the hands of the state or central government 2. Scientific techniques should be adopted for environmental control of catchment areas of rivers, ponds or streams 3. Industrial plants should be based on recycling operations as it helps prevent the disposal of wastes into natural waters but also the extraction of products from waste. 4. Plants, trees and forests control pollution as they act as natural air conditioners. 5. Trees are capable of reducing sulphur dioxide and nitric oxide pollutants and hence more trees should be planted. 6. No type of waste (treated, partially treated or untreated) should be discharged into any natural water body. Industries should develop closed-loop water supply schemes and domestic sewage must be used for irrigation. 7. Qualified and experienced people must be consulted from time to time for effective control of water pollution. 8. Public awareness must be initiated regarding the adverse effects of water pollution using the media. 9. Laws, standards and practices should be established to prevent water pollution and these laws should be modified from time to time based on current requirements and technological advancements. 10. Basic and applied research in public health engineering should be encouraged.

CONTROL AND REDUCTION MEASURES

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