Water pollution 123


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Water pollution 123

  1. 1. Prepared By- Aks hay … Abhi m an yu… 1
  2. 2. Key Concepts  Types, sources, and effects of water pollutants  Major pollution problems of surface water  Major pollution problems of groundwater  Reduction and prevention of water pollution  Drinking water quality 2
  3. 3. Types, Effects, and Sources 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. 3
  4. 4. • Scientists monitor water quality by using bacterial counts, chemical analysis, and indicator organisms. • One method of measuring water quality involves measuring the number of colonies of fecal coliform bacteria present in a water sample . • Drinking water should not contain any colonies/100 milliliters, • Chemical analysis includes checking inorganic and and organic chemicals present, sediment content, turbidity of water. • Indicator species are living organisms that are monitored to determine levels of pollution. 4
  5. 5. Sources of Water Pollution Point sources Nonpoint sources Water quality 5
  6. 6. Point and Non-point Sources NONPOINT SOURCES Rural homes Cropland Urban streets Animal feedlot Suburban development POINT SOURCES Factory Wastewater treatment plant 6
  7. 7. Sources of water pollution 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. 7
  8. 8. • One of every five people in the world lacks access to safe drinking water. • Ninety-five percent of people in developed countries and 74% of people in developing countries have access to clean drinking water. • In a warmer world, too much rain and too little rain can increase water pollution. 8
  9. 9. Pollution of Freshwater Streams 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 entering, flow rate, temperature, wastes and pH levels 9
  10. 10. Oxygen Sag Curve 10
  11. 11. Water Pollution: Now countries have reduced point Most developed 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 . 11
  12. 12. Pollution of Lakes 12
  13. 13. Groundwater Pollution: Causes  Few bacteria  Low flow rates  Low oxygen  Cold temperatures Hazardous waste injection well Coal strip mine runoff Pesticides De-icing road salt Pumping well Waste lagoon Buried gasoline and solvent tank Cesspool septic tank Gasoline station Water pumping well Landfill Accidental spills aq u Sewer ifer Leakage from faulty casing Discharge r ate s hw ifer Confined aquifer fre a qu d ter ine a nf hw n co Groundwater r es U f flow n ed fi on C 13
  14. 14. 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. 14
  15. 15. Ocean Pollution Fig. 22-11 p. 504 15
  16. 16. Case Study: Chesapeake Bay  Largest US estuary  Relatively shallow  Slow “flushing” action to Atlantic  Major problems with dissolved O2 16
  17. 17. Oil Spills Sources: offshore wells, tankers, pipelines and storage tanks Effects: death of organisms, loss of animal insulation and buoyancy, smothering Significant economic impacts Mechanical cleanup methods: skimmers and blotters Chemical cleanup methods: coagulants and dispersing agents 17
  18. 18. Solutions: Preventing and Reducing Surface Water Pollution Non-point S ources Reduce runoff Buffer zone vegetation Point Sources Clean Water Act Water Quality Act Reduce soil erosion 18
  19. 19. Technological Approach: Septic Systems Require suitable soils and maintenance 19
  20. 20. Technological Approach: Advanced (Tertiary) Sewage Treatment Uses physical and chemical processes Removes nitrate and phosphate Expensive Not widely used 20
  21. 21. Drinking Water Quality urban drinking Purification of water Protection from terrorism Purification of rural drinking water Safe Drinking Water -Act Maximum contaminant levels (MCLs) Bottled water 21
  22. 22. Sustaining Biodiversity 22
  23. 23. O ur M tto … o 23
  24. 24. Special Credits – Our Team Members, Our Teachers For Guiding Us in Our Preoject 24
  25. 25. For More PPT’s ContactAkshay (9420832370) 25