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DO NOW. Download ch.17 notes. Dead Zone in the Gulf of Mexico. for every $1 spent on conservation program, $500 spent on subsidies for farmers (fertilizer use). Pollution.

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  1. DO NOW Download ch.17 notes

  2. Dead Zone in the Gulf of Mexico

  3. for every $1 spent on conservation program, $500 spent on subsidies for farmers (fertilizer use)

  4. Pollution • Pollution: “the presence of a substance in the environment that because of its chemical composition or quantity prevents the functioning of natural processes and produces undesirable environmental and health effects.”

  5. Categories of Pollution

  6. Pollution Categories • Air • Particulates • Acid-forming compounds • Photochemical smog • CO2 • CFCs

  7. Pollution Categories • Water and land • Nutrient oversupply • Solid wastes • Toxic chemicals • Pesticides/herbicides • Nuclear waste

  8. Water Pollution: Point Source: dischargeNonpoint Sources: runoff

  9. Water Pollution Types • Pathogens: disease causing microorganisms • Organic wastes • Chemical • Sediments • Nutrients: P and N

  10. Chemical Pollutants • Inorganic chemicals • Heavy metals, acids, road salts • Organic chemicals • Petroleum, pesticides, detergents

  11. Acid Mine Drainage

  12. Development of Wastewater Collection and Treatment Systems • Storm drains for collecting runoff from precipitation • Sanitary sewers to receive all the wastewater from sinks, tubs, and toilets

  13. Development of Sewage Collection and Treatment Systems • Through the 1970s sewage was discharged directly into waterways • Clean Water Act of 1972

  14. Pollutants in Raw Wastewater • 99.9% water to 0.1% waste • Pollutants in sewage are: • Debris and grit • Particulate organic material • Colloidal and dissolved organic material • Dissolved inorganic material

  15. http://www.youtube.com/watch?v=GV-DoisLwm0

  16. http://www.youtube.com/watch?v=f6Uu8CpOn-0 • http://www.youtube.com/watch?v=v_aJWYfm4I4&feature=fvw

  17. Trickling Filters for Secondary Treatment

  18. Trickling Filters for Secondary Treatment

  19. Biological Nutrient Removal • Conversion of NH4 to NO3 • NO3 converted to N gas and released • PO4 taken up by bacteria and released with excess sludge

  20. Treatment of Sludge • Anaerobic digestion • Composting

  21. Anaerobic Sludge Digesters Methane from humus

  22. Dewatering Treated Sludge

  23. Alternative Treatment Systems • On-site wastewater treatment systems – septic tanks • Using effluents for irrigation • Reconstructed wetland systems • Page 453

  24. Septic Tank Treatment • Aerobic digestion of solids in septic tank. • Flow of liquids into drain field for evaporation, infiltration, or irrigation.

  25. Eutrophication • Different kinds of aquatic plants • The impacts of nutrient enrichment • Combating eutrophication

  26. Eutrophication in Shallow Lakes and Ponds • As nutrients are added from pollution, an oligotrophic condition rapidly becomes eutrophic. Oligotrophic Eutrophic

  27. Natural and Cultural Eutrophication • Natural eutrophication • aquatic succession • occurs over several hundreds of years • Cultural eutrophication • driven by human activities • occurs rapidly

  28. Combating Eutrophication • Attack the symptoms • Chemical treatment • Aeration • Harvesting aquatic weeds • Drawing water down

  29. Combating Eutrophication • Getting at root cause • Controlling point sources • Controlling nonpoint sources

  30. Controlling Point Sources • Point Source: effluent from a pipe • Ban phosphate detergents • Sewage-treatment improvements

  31. Controlling Nonpoint Sources • Difficult to address runoff pollutants • Urban • Agricultural fields • Deforested woodlands • Overgrazed pastures

  32. Controlling Nonpoint Sources • Best Management Practices (BMP): Table 17-2 • Agriculture • Construction • Urban

  33. Collecting Pond for Dairy-Barn Washings

  34. Lesson Activity • In some States, bio-solids are dried, bagged, and sold commercially for garden use, similar to cow manure or compost (Milorganite in Milwaukee for example) How is milorganite used? http://www.milorganite.com/

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