ppt on water pollution(for lpu students especially)
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ppt on water pollution(for lpu students especially)
- 3. Fig. 15-2 p. 307 Freshwater Readily accessible freshwater Biota 0.0001% Rivers 0.0001% Atmospheric water vapor 0.0001% Lakes 0.0007% Soil moisture 0.0005% Groundwater 0.592% Ice caps and glaciers 0.592% 0.014%
- 4. Humans use about 54% of reliable runoff Agriculture Industry Domestic Power plants Fig. 15-4 p. 309 United States Industry 11% Public 10% Power cooling 38% Agriculture 38%
- 5. Two types of water subject to pollution •Surface water – rivers, lakes, oceans • Uses: drinking, recreational [fishing, boating, swimming], irrigation. •Groundwater- occurs beneath a water table in soils or rocks; subject to pollution from toxic chemicals. • Uses: drinking, irrigation, etc
- 6. • Water pollution • Point sources • Located at specific places • Easy to identify, monitor, and regulate • Examples
- 7. Nonpoint sources ◦ Broad, diffuse areas ◦ Difficult to identify and control ◦ Expensive to clean up ◦ Examples
- 8. Other sources of water pollution ◦ Parking lots ◦ Human-made materials E.g., plastics ◦ Climate change due to global warming
- 11. Fig. 20-A, p. 535 Good 8–9 Water Quality DO (ppm) at 20°C Slightly polluted 6.7–8 Moderately polluted 4.5–6.7 Heavily polluted Gravely polluted Below 4 4–4.5
- 12. Fig. 20-5, p. 536 Point source Pollution- tolerant fishes (carp, gar)Types of organisms Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Fish absent, fungi, sludge worms, bacteria (anaerobic) Pollution- tolerant fishes (carp, gar) 8 ppm Normal clean water organisms (Trout, perch, bass, mayfly, stonefly) Dissolved oxygen (ppm) 8 ppm Biochemical oxygen demand Clean Zone Recovery ZoneSeptic Zone Decomposition Zone Clean Zone
- 15. Low flow rates Few bacteria Cold temperatures Low oxygen
- 16. Sources of contamination ◦ For Surface water Rivers and lakes Point source: -sewage [municipal or private] - industrial wastes Non-point source: Agricultural activity [e.g. pesticides, fertilizers]. urban and highway water runoff. Ocean [oil spills, dumping, land-based sources] Oil spills – during transportation, either accidentally or intentionally Dumping –sewage, chemical disposal, radioactive materials Land-based sources –migration of chemical substances.
- 17. I) Fund pollutants ◦ -Environment has some assimilative capacity. If capacity for absorption higher than rate of injection, they may not accumulate. a) Degradable ◦ degrades/break into component parts within water. Are normally organic residuals attacked and broken down by bacteria and become less harmful. b) Thermal pollution ◦ caused by injection of heat into watercourses by an industrial plant or electric utility using surface water as a coolant, and returning the heated water to the watercourse.
- 18. Fig. 20-12, p. 543 Leaking tank Aquifer Bedrock Water table Groundwater flow Gasoline leakage plume (liquid phase) Free gasoline dissolves in groundwater (dissolved phase) Migrating vapor phase Contaminant plume moves with the groundwater Water well
- 19. c) Plant nutrients [nitrogen and phosphorus] [eutrophic/ eutrophication =excess supply of nutrients in a lake] ◦ stimulate growth of aquatic plant life, e.g. algae and water weeds. ◦ can produce odor if in excess. d) Infectious organisms [e.g. bacteria and viruses] ◦ carried into both ground and surface water by domestic and animal wastes; industrial wastes e.g. tanning and meat packaging ◦ Are live organisms that may thrive and multiply in water or decline.
- 20. Fig. 20-15, p. 548 Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries. Cities Toxic metals and oil from streets and parking lots pollute waters; sewage adds nitrogen and phosphorus. Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilizer from lawns adds nitrogen and phosphorus. Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight. Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus. Red tides Excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals. Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat. Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish. Closed shellfish bedsClosed beach Oxygen-depleted zone
- 21. I) Oil spills – covered under the Clean Water Act: ◦ prohibits discharges of harmful quantities of oil into navigable waters ◦ industry assume responsibility for any damage [clean up; compensation for environmental restoration. II) Dumping ◦ Marine Protection Research and Sanctuaries Act, 1972. address discharges of waste within U.S. territorial limits by U.S. vessels or persons in any ocean waters.
- 22. Unlike point source, is largely state responsibility ◦ Federal grants for state-initiated plans for waste treatment management. ◦ Federal programs for aiding control of non-point sources e.g. Conservation Reserve Program aimed at removing 40-45 million acres of erodible land from cultivation.
- 25. Fig. 20-13, p. 545 SOLUTIONS Groundwater Pollution Prevention Cleanup Find substitutes for toxic chemicals Pump to surface, clean, and return to aquifer (very expensive) Keep toxic chemicals out of the environment Install monitoring wells near landfills and underground tanks Inject microorganisms to clean up contamination (less expensive but still costly) Require leak detectors on underground tanks Ban hazardous waste disposal in landfills and injection wells Store harmful liquids in aboveground tanks with leak detection and collection systems Pump nanoparticles of inorganic compounds to remove pollutants (still being developed)
- 26. Fig. 20-17, p. 551 SOLUTIONS Coastal Water Pollution Prevention Cleanup Reduce input of toxic pollutants Improve oil-spill cleanup capabilities Separate sewage and storm lines Use nanoparticles on sewage and oil spills to dissolve the oil or sewage (still under development) Ban dumping of wastes and sewage by ships in coastal waters Ban ocean dumping of sludge and hazardous dredged material Require secondary treatment of coastal sewageRegulate coastal development, oil drilling, and oil shipping Use wetlands, solar- aquatic, or other methods to treat sewage Require double hulls for oil tankers
- 30. Reservoirs and purification plants Process sewer water to drinking water Expose clear plastic containers to sunlight (UV) Nanofilters The LifeStraw
- 32. Non-point source control is the least developed of water pollution control programs/policies.
Editor's Notes
- Figure 20.A Water quality as measured by dissolved oxygen (DO) content in parts per million (ppm) at 20 °C (68 °F). Only a few fish species can survive in water with less than 4 ppm of dissolved oxygen at this temperature. Some warmer water species have evolved ways to tolerate low DO levels better than cold water species can. Question: Would you expect the dissolved oxygen content of polluted water to increase or decrease if the water is heated? Explain.
- Figure 20.5 Natural capital: dilution and decay of degradable, oxygen-demanding wastes (or heated water) in a stream, showing the oxygen sag curve (blue) and the curve of oxygen demand (red). Depending on flow rates and the amount of biodegradable pollutants, streams recover from oxygen-demanding wastes and from injection of heated water if they are given enough time and are not overloaded (Concept 20-2A). See an animation based on this figure at CengageNOW™. Question: What would be the effect of putting another biodegradable waste discharge pipe to the right of the one in this picture?
- Figure 20.12 Natural capital degradation: groundwater contamination from a leaking gasoline tank. As the contaminated water spreads from its source in a widening plume, it can be extracted by wells used to provide water for drinking and irrigation.
- Figure 20.15 Natural capital degradation: residential areas, factories, and farms all contribute to the pollution of coastal waters and bays. According to the U.N. Environment Programme, coastal water pollution costs the world $16 billion annually—more than $30,000 a minute—due to ill health and premature death. Question: What are three changes you could make in your lifestyle that might help to prevent this pollution?
- Figure 20.13 Methods for preventing and cleaning up contamination of groundwater (Concept 20-3B). Question: Which two of the preventive solutions (left) do you think are the most important? Why?
- Figure 20.17 Methods for preventing and cleaning up excessive pollution of coastal waters (Concept 20-4B). Question: Which two of these solutions do you think are the most important? Why?