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Water pollution


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Water pollution

  1. 1. WATER POLLUTION<br />
  2. 2. Kinds of Water Pollution<br />Inorganic Pollutants<br />Organic Pollutants<br />Biologic Pollutants<br />
  3. 3. Inorganic Pollutants<br />Examples:<br />Pb in gasoline<br />Radio nuclides<br />Phosphorus, nitrogen (Great Lakes)<br />Other heavy metals<br />
  4. 4. Radio nuclides<br />Bikini Atoll in South Pacific: > 20 tests, 1946-1958<br />Inhabitants evacuated before 1946 tests; their descendents are still exiled<br />Atmospheric testing of nuclear weapons is now banned<br />National labs…now trying to clean up (Hanford)<br />
  5. 5. Phosphates and Nitrates<br />Phosphates—mostly a result of sewage outflow and phosphate detergents<br />Additional phosphate grows excess algae…oxygen depletion, Lake Erie…1972 phosphate management plant…$7.6 billion<br />Nitrates—sewage and fertilizers<br />
  6. 6. Organic Pollutants<br />Three classes of compounds<br />Pesticides and Herbicides<br />Materials for common household and industrial use<br />Materials for industrial use<br />
  7. 7. Pesticides<br />Chlorinated hydrocarbons<br />DDT, heptachlor, etc—2-15 years<br />Organophosphates<br />Malathion, methyl parathion—1-2 weeks<br />Carbamates<br />Carbaryl, maneb, aldicarb—days to weeks<br />Pyrethroids<br />Pemethrin, decamethrin—days to weeks<br />
  8. 8. Herbicides<br />Contact<br /> Triazines—e.g. atrazine, paraquat<br /> (interfere with photosynthesis)<br />Systemic—phenoxy compounds, N compounds, Alar, glyphosate<br /> (create excess growth hormones)<br />Soil sterilants<br /> trifluralin, dalapon<br /> (kill soil microorganisms)<br />
  9. 9. Effects and Sources of Water Pollution<br /><ul><li>Point sources
  10. 10. Nonpoint sources</li></ul>Fig. 22-3 p. 494<br />
  11. 11. Point and Nonpoint Sources<br />NONPOINT SOURCES<br />Rural homes<br />Cropland<br />Urban streets<br />Animal feedlot<br />POINT SOURCES<br />Suburban development<br />Factory<br />Wastewater treatment plant<br />Fig. 22-4 p. 494<br />
  12. 12. Solutions: Preventing and Reducing Surface Water Pollution<br />Nonpoint Sources<br />Point Sources<br /><ul><li>Reduce runoff
  13. 13. Clean Water Act
  14. 14. Buffer zone vegetation
  15. 15. Water Quality Act
  16. 16. Reduce soil erosion</li></li></ul><li>Pollution of Lakes<br />Eutrophication <br />Fig. 22-7 p. 499<br />
  17. 17. Groundwater Pollution: Causes<br /><ul><li>Low flow rates
  18. 18. Few bacteria
  19. 19. Low oxygen
  20. 20. Cold temperatures</li></ul>Hazardous waste injection well<br />Pesticides<br />Coal strip mine runoff<br />De-icing road salt<br />Buried gasoline and solvent tank<br />Cesspool septic tank<br />Pumping well<br />Gasoline station<br />Waste lagoon<br />Water pumping well<br />Sewer<br />Landfill<br />Leakage from faulty casing<br />Accidental spills<br />Discharge<br />Unconfined freshwater aquifer<br />Confined aquifer<br />Confined freshwater aquifer<br />Groundwater flow<br />Fig. 22-9 p. 502<br />
  21. 21. Groundwater Pollution Prevention<br /><ul><li>Monitor aquifers
  22. 22. Find less hazardous substitutes
  23. 23. Leak detection systems
  24. 24. Strictly regulating hazardous waste disposal
  25. 25. Store hazardous materials above ground</li></li></ul><li>Ocean Pollution<br />Fig. 22-11 p. 504<br />
  26. 26. Dumping wastes in the oceans<br />Dumping industrial wastes off US coasts has stopped, but dredge products are legally dumped at 110 sites in Atlantic, Pacific, and Gulf Coasts<br />US has banned dumping sewage sludge in ocean since 1992<br />50 countries rep ~80% of world’s shipping fleet have agreed not to dump sewage and garbage<br />London Dumping Convention of 1972; 1994<br />
  27. 27. Oil Spills<br /><ul><li>Sources: offshore wells, tankers, pipelines and storage tanks
  28. 28. Effects: death of organisms, loss of animal insulation and buoyancy, smothering
  29. 29. Significant economic impacts
  30. 30. Mechanical cleanup methods: skimmers and blotters
  31. 31. Chemical cleanup methods: coagulants and dispersing agents</li></li></ul><li>Oil spills<br />
  32. 32. Oil Pollution in the Oceans<br />Oil Pollution Act of 1990<br />Only about 15% of an oil spill can now be recovered<br />Crude oil—3 years<br />Refined oil– 10-20 years<br />
  33. 33. Solutions<br />Coastal Water Pollution<br />Prevention<br />Cleanup<br />Reduce input of toxic pollutants<br />Improve oil-spill cleanup <br />capabilities<br />Separate sewage and storm lines<br />Ban dumping of wastes and sewage by maritime and cruise ships in coastal waters<br />Sprinkle nanoparticles over an oil or sewage spill to dissolve the oil or sewage without creating harmful byproducts<br />(still under development)<br />Ban ocean dumping of sludge and hazardous dredged material<br />Protect sensitive areas from development, oil drilling, and oil shipping<br />Require at least secondary <br />treatment of coastal sewage<br />Regulate coastal development<br />Use wetlands, solar-aquatic, or<br />other methods to treat sewage<br />Recycle used oil<br />Require double hulls for oil tankers<br />
  34. 34. Reducing water pollution<br />Non point source<br />Septic tanks and sewers<br />
  35. 35. Reducing agriculturally produced pollution<br />2002: feed lot ruling<br />Credit trading<br />Agricultural: soil erosion, reforestation, cover crops, reduced fertilizers and pesticides, buffer zones<br />
  36. 36. Technological Approach: Septic Systems<br /><ul><li>Require suitable soils and maintenance</li></ul>Fig. 22-15 p. 510<br />
  37. 37. Sewage Treatment<br /><ul><li>Physical and biological treatment</li></ul>Fig. 22-16 p. 511<br />
  38. 38. Technological Approach: Using Wetlands to Treat Sewage<br />Fig. 22-18 p. 513<br />
  39. 39. Solutions<br />Water Pollution<br /><ul><li>Prevent groundwater contamination
  40. 40. Greatly reduce nonpoint runoff
  41. 41. Reuse treated wastewater for irrigation
  42. 42. Find substitutes for toxic pollutants
  43. 43. Work with nature to treat sewage
  44. 44. Practice four R's of resource use (refuse, reduce, recycle, reuse)
  45. 45. Reduce resource waste
  46. 46. Reduce air pollution
  47. 47. Reduce poverty
  48. 48. Reduce birth rates</li></li></ul><li>THANK YOU<br />