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Chapter 11

Chapter 11. Water Resources & Water Pollution. Water. Hydrogen bonding – strong attractive forces Water expands when it freezes Liquid phase is 0 º C (32 ºF) to 100ºC (212ºF) High heat capacity (4.184 J/g-º C) Excellent solvent – dissolves many cmpds Self ionization of water

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Chapter 11

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  1. Chapter 11 Water Resources & Water Pollution

  2. Water • Hydrogen bonding – strong attractive forces • Water expands when it freezes • Liquid phase is 0ºC (32ºF) to 100ºC (212ºF) • High heat capacity (4.184 J/g-ºC) • Excellent solvent – dissolves many cmpds • Self ionization of water • Filters UV in aquatic systems • High surface tension • High wetting ability

  3. Water Supports All Life • Poorly managed resource • We waste it • We pollute it • Availability • 97.4% is salt water • 2.6% is usable for fresh water • Usable water

  4. Usable Fresh Water • The 2.6% is the following: • Polar caps • Deep ground water (gw) • Usable fresh water is: • Ground water • Water vapor • Streams & lakes • World supply of water • Equated to 26 gal total:2.5 teaspoons for us • Hydrologic Cycle

  5. Global Warming • Global warming can increase the rate of evaporation • Shift precipitation patterns • Disrupt water supplies • Disrupt food supplies • River & stream flow rates may change

  6. Types of Water Resources • Surface water – does not penetrate the ground • Runs off to bodies of water • Evaporates into the atmosphere • Ground water – percolates through the soil and rocks • Zones of saturation

  7. Ground Water • Zones of Saturation • Water table is the top • Aquifers lie along the bedrock • Naturally recharge • Fluctuates by elevation & pressure • Flow depends on the level of the water table, stream elevation, etc

  8. Human Influence • Data from 2002 • During the last century, the population increased 3X while the water consumption increased 7X • Use 55% of the available water • For over 500 million people, water is scarce • Projected for 2025 • Use will increase to 70% of available water • 2.4-3.4 billion people, water will be scarce

  9. Annual Precipitation • 41cm or less/year • Western US • 41-81cm/year • Middle US states • 81-122cm/year • Northeastern US • 122cm or more/year • Southeastern states • West costal land • Much of the US experience water shortages

  10. Fresh Water Supply • Dams and reservoirs stop runoffs • Reroute surface water to more needed areas • Withdraw gw from depths • Desalinate water to remove salt • Reduce waste • Reclaim fresh water

  11. Desalination • Processes • Distillation – boiling off water & purifying it • Reverse osmosis – forcing it through a membrane to remove the salt • Disadvantages • Expensive • Produces large amounts of waste salts • Example - web

  12. Flooding • Heavy rain & snow melts • Floodplains – productive wetlands • Fertile soil • Ample water • Suitable water recreation • Recharge the ground water

  13. Reduce Flooding • Channelization • Straighten streams • Deepen stream beds • Increase stream flow, you increase erosion • Build levees • Contain and speed up flow • Build dams • Contain water in reserves • Identify and manage flood prone areas

  14. Sources of Water Pollution • Change in water quality • Infectious agents • Oxygen demanding waste • Inorganic chemicals • Organic chemicals • Excess plant nutrients • Sediments • Radioactive materials • Heat (thermal pollution)

  15. Water Quality • Coli form bacteria • WHO 0/100ml drinking water • EPA 200 colonies/100 ml swimming water • Dissolved oxygen • Biological oxygen demand - BOD • Chemical analysis – chemical pollutants • Indicator species – reveal certain pollutants

  16. Sources of Water Pollution • Point Source – can identify the source of the pollution • For example – a water or sewer pipe • Non-point Source – can not be traced to any one particular site • For example – agricultural runoff (which farm?)

  17. Safe Drinking Water • 1970 – 30% of developed countries had safe drinking water • 2000 – 72% had safe drinking water • Still 1.4 billion people world wide that do not have safe drinking water • Cost would be $23 billion/year for 8-10 years to provide safe drinking water for all

  18. Pollution of Fresh Water • Flowing streams can recover fast • US Stream Data • Large amount of aquatic species die • Hudson River clean-up • Burning of Cuyahoga River (1959 & ‘69) • Lakes flow less and contain stratified layers • Pollution remains longer • Settles in the benthic layer in a concentration of pollutants • Eaten by organisms that are part of the food web

  19. Cultural Eutrophication (CE) • Nutrient rich inputs into a lake • Nutrients added by humans (nitrates & phosphates) • Hot weather promotes dense growth of weeds • Decomposition of weed produce excess nutrients • Anaerobic bacteria take over

  20. Preventing CE • Waste water treatment • Ban or limit the use of phosphate soaps • Soil conservation • Clean-up • Mechanically remove weeds • Control weeds by herbicides & algaecides • Introduce oxygen into the water

  21. Groundwater Pollution • Principle water supply • Can not recover • One or more organic chemical pollutants are found in 45% of municipal water supplies • Out of 26,000 industrial waste pond & lagoons, 1/3 are not lined to prevent toxic liquid waste from entering the groundwater

  22. Ocean Pollution • Off shore dumping • Dredge spoils • Sewage sludge – toxic mixture of chemicals and infectious agents • Coastal areas input waste directly and many are untreated • Beach pollution • Shellfish contamination • Human viruses from raw sewage • Crude oil & refined petroleum spills

  23. Oil Spill Clean-up • Mechanical methods • Vacuum • Floating booms • Absorbent agents • Chemical methods • Coagulating agents • Dispersing agents • Fire • Physical methods • Natural wave action • Biological methods • Bacteria

  24. Clean Water Acts • 1972 – Federal Water Pollution Act • 1977 – Clean Water Act • 1987 – Water Quality Act • All set standards • Allowable levels of key pollutants • Requires polluters to have permits • Discharge trade policy (buy credits from permit holders)

  25. Point Source • Water Treatment Technologies • Primary – screens debris and allows solids to settle • Secondary – biological process (aerobic bacteria degrade 90% • Port Labelle www.southerndatastream.com

  26. Slides for NSF Research Trip • Miller Brewing Company in Fulton, NY had an underground chemical tank rupture. • The next slide is a picture of the abatement tower that allowed the water to pass over a column of resin beads to remove the contaminated VOC’s. • The aquifer under the Miller plant contaminated the water supply for villages surrounding the area

  27. Miller Brewing Company

  28. Oswego City Harbor • Core samples were taken from the Oswego Harbor looking for lead, zinc and other metals in the sediment. • The next 2 slides show the sampling of the sediment in the harbor

  29. Core Sample – Lake Ontario

  30. Core Sample – Lake Ontario

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