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- 1. A seminar on WATER POLLUTION 1 Prepared byPreparedby MD TANZIL ALAMMD TANZIL ALAM
- 2. INTRODUCTION 2 • Waterpollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. • Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.
- 3. KEY CONCEPT 3 Types,sources, and effects of water pollutantsTypes, sources, and effects of water pollutants Major pollution problems of surface waterMajor pollution problems of surface water Major pollution problems of groundwaterMajor pollution problems of groundwater Reduction and prevention of water pollutionReduction and prevention of water pollution
- 4. Types, Effects, andSources of Water Pollution Water is polluted by infectious bacteria, inorganic and organic chemicals, and excess heat. Water pollution is any chemical, biological, or physical change in water quality that has a harmful effect on living organisms. The WHO estimates that 3.4 million people die prematurely each year from waterborne diseases. In the U.S., an estimated 1.5 million people a year become ill from infectious agents. 4
- 5. Types of waterpollution Nutrients Pollution Surface water pollution Oxygen Depleting Ground water pollution Microbiological Suspended Matter Chemical Water Pollution Oil Spillage 5
- 6. Sources of WaterPollution 6 POINT SOURCEPOINT SOURCE pollution flowing from a single and identifiablepollution flowing from a single and identifiable source such as discharge pipe from a factory,source such as discharge pipe from a factory, roadway, or leaking underground storage tankroadway, or leaking underground storage tank NON-POINT SOURCENON-POINT SOURCE pollution collected by rain falling over a largerpollution collected by rain falling over a larger watershed which is then carried by runoff to awatershed which is then carried by runoff to a nearby lake or stream, or by infiltration intonearby lake or stream, or by infiltration into the groundwaterthe groundwater
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- 9. Point and NonpointSources 9 NONPOINT SOURCES Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES
- 10. Sources of waterpollution The leading sources of water pollution are agriculture, industries, and mining. 1. Agricultural activities - are the leading cause of water pollution from erosion, overgrazing, fertilizers and pesticides, and excess salt from irrigated soils. 2. Industrial facilities - are another large source of water pollution, and mining is a third source. 10
- 11. Pollution of FreshwaterStreams Streams can recover from moderate levels of degradable water pollutants if the flows are not reduced. 1. A combination of dilution and biodegradation can allow recovery of stream pollution 2. The breakdown of pollutants by bacteria creates an oxygen sag curve. Organisms that have a high oxygen demand can’t survive in the curve. 3. Volume of the stream, volume of wastes entering, flow rate, temperature, and pH levels all affect how great a sag curve is produced. 11
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- 13. Water Pollution: Now •Most developed countries have reduced point source pollution, but toxic chemicals and pollution from non-point sources are still problems. • Stream pollution in most developing countries is a serious and growing problem. Half of the world’s 500 major rivers are heavily polluted, and most of them run through developing countries where waste treatment is minimal or nonexistent. • For example: Religious beliefs, cultural traditions, poverty, little economic development, and a large population interact to cause severe pollution of the Ganges River in India. 13
- 14. Groundwater Pollution: Causes 14 Coalstrip mine runoff Pumping well Waste lagoon Accidental spills Groundwater flow Confined aquifer Discharge Leakage from faulty casing Hazardous waste injection well Pesticides Gasoline station Buried gasoline and solvent tank Sewer Cesspool septic tank De-icing road salt Unconfined freshwater aquifer Confined freshwater aquifer Water pumping well Landfill
- 15. Pollution of Groundwater Experts rate groundwater pollution as a low-risk ecological problem; it is rated as a high-risk health problem. The extent of groundwater contamination is generally unknown Prevention is the most effective and affordable way to protect groundwater from pollutants. 15
- 16. Solutions: Preventing and ReducingSurface Water Pollution 16 Nonpoint SourcesNonpoint Sources Point SourcesPoint Sources • Reduce runoffReduce runoff • Buffer zone vegetationBuffer zone vegetation • Reduce soil erosionReduce soil erosion • Clean Water ActClean Water Act • Water Quality ActWater Quality Act
- 17. How can westop water pollution 17 Education Governments, local councils and laws Economics Our clean future
- 18. Conclusion 18 Clearly, theproblems associated with water pollution have the capabilities to disrupt life on our planet to a great extent. Congress has passed laws to try to combat water pollution thus acknowledging the fact that water pollution is, indeed, a serious issue. But the government alone cannot solve the entire problem. It is ultimately up to us, to be informed, responsible and involved when it comes to the problems we face with our water. We must become familiar with our local water resources and learn about ways for disposing harmful household wastes so they don't end up in sewage treatment plants that can't handle them or landfills not designed to receive hazardous materials
- 19. References 19 1. Gannon,RW; Osmond, DL; Humenik, FJ; Gale, JA; Spooner, J Agricultural Water Quality WATER RESOUR BULL, vol. 32, no. 3, pp. 437-450, 1996 2. U.S. ENVIRONMENTAL PROTECTION AGENCY, WASHINGTON, DC (USA), 1996, 253 pp 3. MacKenzie, SH The Ecosystem ISLAND PRESS, CA (USA), 1996, 240
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