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Water: Resources and Water Pollution

Water: Resources and Water Pollution. Chapter 11. Planet Earth: the water planet. http:// sealevel.jpl.nasa.gov /images/videos/The_Water_Planet_264.mov. Ocean Currents. NASA Visualization of Ocean Currents. The Hydrologic Cycle. The Hydrologic Cycle Constantly Redistributes Water.

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Water: Resources and Water Pollution

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  1. Water: Resources and Water Pollution Chapter 11

  2. Planet Earth: the water planet http://sealevel.jpl.nasa.gov/images/videos/The_Water_Planet_264.mov

  3. Ocean Currents NASA Visualization of Ocean Currents

  4. The Hydrologic Cycle

  5. The Hydrologic Cycle ConstantlyRedistributes Water • Water cycles through environment • Describe cycle: • evaporation from moist surfaces/water • precipitation • run-off (rivers/lakes); soil percolation (ground water) • through living organisms • solar energy drives the hydrologic cycle • water and sunlight are unevenly distributed around the globe, thus water resources are very uneven

  6. Mean Annual Precipitation

  7. Water in the World water covers 71% of earth’s surface

  8. - - - - O O O O H H H H H H H H + + + + + + + + Unique Properties of Water due to molecular structure a polar molecule - excellent solvent hydrogen bonding between water molecules cohesion tensile strength between water and other molecules adhesion capillarity - from cohesion and adhesion

  9. Case Study: Ch 11, When will Lake Mead go dry?

  10. Case Study: Ch 11, When will Lake Mead go dry? Reasons for dams? • flood control • electricity generation • water source • recreation

  11. Case Study: Ch 11, When will Lake Mead go dry? I tell you gentlemen; you are piling up a heritage of conflict and litigationof water rights, for there is not sufficient water to supply the land. –John Wesley Powell (1893)

  12. Case Study: When will Lake Mead go dry? 11-13

  13. The Colorado River System LAKE MEAD, Nev. — The sinuous Colorado River and its slew of man-made reservoirs from the Rockies to southern Arizona are being sapped by 14 years of drought nearly unrivaled in 1,250 years. • Colorado River Drought Forces a Painful Reckoning for States, New York Times, MICHAEL WINES JAN. 5, 2014 11-14

  14. Unique Properties of Water 1. liquid over wide range of temperatures due to cohesion boiling = 100°C (212°F) freezing = 0°C (32°F) 2. high heat capacity (slowly changes temperature) • stores heat well and can resists temperatures changes • coastal areas have less temperature fluctuations than continental areas • moderates earth temperature 3. requires much energy to evaporate skin furnishes heat and thus cools body

  15. Unique Properties of Water 4. great solvent (of polar compounds) • polarity of water molecule keeps ions apart • salt (NaCl) ionizes in water

  16. as water evaporates from the leaf surface, a column of water is pulled upward from the soil water Unique Properties of Water 5. surface tension and high wetting ability cohesion and adhesion cause water to rise in plants

  17. Unique Properties of Water 6. Expands when freezes ice floats (insulates) 7. Density increases as temperature decreases: most dense at 4°C • bodies of water (lakes and streams) remain liquid in winter • turnover can occur in lakes in spring and fall

  18. Surface Water • water that remains on earth’s surface as a result of precipitation • water in streams, lakes, wetlands, reservoirs • watershed • land region draining into a body of water • Stagecoach Lake • in lab we determined that lake’s watershed • Impact of Rachel Carson’s Silent Spring

  19. Biological Amplificaiton Rachel Carson, 1962 Silent Spring 10,000,000X increase in concentration

  20. Biomagnification cont’d • Clear Lake, California (90 mi N San Francisco) • copious numbers of gnats (not a mosquito) • 1949 - DDD (DDT relative) applied to lake • 1 part DDD : 70,000,000 parts water • 1/70 parts per million • 1954 - control repeated (now not as affective) • 1 part DDD : 50,000,000 parts water • 1/50 parts per million • 1955 Western Grebes starting to die • 1957 - 3rd wave of DDD application • more Western Grebes die; analysis of bird tissue: • 1600 parts DDD per million • 112,000 X increase in concentration

  21. Ground Water • water that percolates downward through spaces in soil and rock • zone of aeration • upper soil layers that hold both air and water • zone of saturation • region of rock and soil that always maintains water in the spaces • water table begins at the zone of saturation • aquifer • water-saturated layers of rock, sand, gravel through which groundwater flows • relatively impermeable layers (rock & clay) keep water contained in aquifer • recharge area - land area that has water percolating downward into the aquifer

  22. Groundwater System

  23. Groundwater Problems • Two kinds of problems reduce groundwater’s utility: • Discharge problems • Groundwater pollution • Withdrawal problems • Depletion • Land subsidence • Salt water intrusion • Groundwater is very vulnerable to pollution, which is costly and time-consuming to clean up. • Withdrawal problems occur because human pumping can remove water from aquifers much faster than they recharge.

  24. McCook, NE

  25. Ogallala Aquifer • world’s largest know aquifer • irrigation increases yields 2X to 3X • central pivot irrigation removes much water from the aquifer • essentially nonrenewable (slow recharge rate) • pumped 8-10X times faster than recharge rate • expect 25% reduction by 2020 • What are solutions?

  26. Areas with Groundwater Problems

  27. Groundwater Pollution

  28. Water Quality Today

  29. Pollution of Water Sources • turn to neighbor and think of as many kinds of water pollution as possible • I’ll give you a short time to do this (minute or less) • The group with the most, of course, wins

  30. Schistosomiasis occurrence Giardia Classes of Water Pollution 1. disease-causing agents (pathogens) • bacteria (causing dysentery, enteritis) • coliform bacteria (Escherischia coli = E. coli) • normally live in intestinal tract of animals • indicators of fecal contamination if present in water • 0 bacteria/100ml water for drinking - WHO recommendation • 200 bacteria/100ml water for swimming - EPA recommendation • viruses • infectious hepatitis • parasites • protozoans (Giardia) • worms (Schistosomiasis)

  31. Classes of Water Pollution 2. Oxygen-demanding wastes • wastes that decompose (organic) by oxygen requiring (aerobic) bacteria • the bacteria thus reduce DO in water • this impacts all aquatic life - food chain (web)

  32. Classes of Water Pollution 2. Oxygen-demanding wastes • Biological Oxygen Demand is the amount of oxygen required for microbial metabolism of organic compounds in water • high organic compounds increases BOD, leading to low quality water microorganisms feed on organic compounds in water restricts biodiversity in water larger organisms with gills have inadequate oxygen to breath feeding depletes oxygen in water more organic compounds = greater feeding reduces oxygen in water greatly

  33. Classes of Water Pollution 3. water-soluble inorganic chemicals • acids, salts, compounds of toxic metals (mercury & lead)

  34. Classes of Water Pollution 4. Inorganic plant nutrients • water-soluble nitrates, phosphates • from where do these originate?

  35. Classes of Water Pollution 5. organic chemicals • oil, gasoline, plastics, pesticides, cleaning solvents, detergents • Jan 9, 2014: Elk River (Charleston, WV) • MCHM (4-methylcyclohexanemethanol), a chemical foam used to wash coal to reduce pollution; 7500 gal • upstream from drinking water intake and distribution center • Pipeland oil leaks – many each year, most with no attention • (Arkansas – Mar 29, 2013, Missouri – Apr 30; North Dakota – Sep 29) • BP Deepwater Horizon oil spill (Apr 20, 2010) • Exxon Valdez oil spill – tanker, Mar 24, 1989)

  36. Classes of Water Pollution 6. sediment or suspended matter soil erosion 7. water-soluble radioactive isotopes 8. thermal pollution • cooling of industrial and power plants • coal, nuclear & oil fired electric plants create steam to drive turbines

  37. Classes of Water Pollution 9. genetic pollution introduction of non-native species Water hyacinth has been called the worst aquatic plant in the world! It is native to South America, but has been naturalized in most of the southern United States and in many of the world's subtropical and tropical climates. It has a tremendous growth and reproductive rate and its free-floating mats cause substantial problems when it grows outside of its native range. Millions of dollars are spent each year in the United States for its management. Water hyacinth has been widely distributed because of the beauty of its large, purple to violet flowers.

  38. Sewage Treatment • Rationale • More than 500 pathogenic bacteria, viruses, and parasites can travel from human or animal excrement through water. • Natural Processes • In many areas, outdoor urination and defecation is the norm. • When population densities are low, natural processes can quickly eliminate waste. • Artificial Wetlands Are a Low Cost Method • Natural water purification • Effluent can be used to irrigate crops or raise fish for human consumption.

  39. Lincoln Wastewater Facilities Underneath and throughout Lincoln are over 1,000 miles of sanitary sewer lines and 16 pumping stations 114 employees at solid waste and wastewater facilities Theresa Street Facility 27th & Cornhusker 20 million gallons of water daily Northeast Facility 5 million gallons of water daily Combined this would fill Holmes Lake in 3.5 days

  40. Lincoln Northeast Treatment Facility 7. solids dewatering 6. solids digestion 5. disinfection 4. secondary clarifiers 1. screening and grit basin 2. primary clarifiers 3. aeration basin

  41. Municipal Sewage Treatment 1. Primary Treatment - Physical separation of large solids from the waste stream • screening, pumping, grit removal • get the big stuff out • material collected hauled to landfill • primary clarification • removes settleable solids • removes floatable materials like grease • 2-4 hrs primary clarifier

  42. Municipal Sewage Treatment 2. Secondary Treatment - Biological degradation of dissolved organic compounds • Biological Treatment • Aeration basin • removes pollutants with bacteria and protozoans • must be aerated • 8 hrs • Secondary clarification • separates treated wastewater from microorganism (from aeration basin) • Disinfection • chlorination or UV light

  43. Municipal Sewage Treatment Anaerobic Digesters 2. Solids processing - Biological degradation of dissolved organic compounds • solids digestion • anaerobic digesters to stabilize organic solids • produce methane gas (CH4) which can power turbine to generate electricity • 18-20 days • solids dewatering • removes excess water • solids (organ rich material) Belt Filter Press Dewatering

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