chapter ENvironment Chapter #2 Water Pollution

Chapter #22�Water Pollution

1. Chapter
#
22
Water Pollution

2. In-class Discussion Readers:
Chapter
#
1 -Me
Chapter
#
2 –David Dudley
Chapter
#
3 –Elizabeth Goodrich
Chapter
#
4 –James McLeod
Chapter
#
5 –Labecca Hampton and Jessica Vidal
Chapter
#
6 –Patrick Grennan and Scott Arnold
Chapter
#
7 –William Arnold
Chapter
#
8 –Crisy Overgard
Chapter
#
9 –Juan Rodriguez

3. Overview
oTypes of Water Pollution
•Sewage
•Disease-causing agents
•Sediment pollution
•Inorganic plant and algal nutrients
•Organic compounds
•Inorganic chemicals
•Thermal pollution
oWater Quality Today
oImproving Water Quality
oLaws Controlling Water Pollution

4. Types of Water Pollution
oWater pollution
•Any physical or chemical change in water that adversely
affects the health of humans and other organisms
•Varies in magnitude by location
oMajor water pollution issue globally
•Lack of disease-free water
oEight categories
•Sewage, disease-causing agents, sediment pollution,
inorganic plant and algal nutrients, organic compounds,
inorganic chemicals, radioactive substances, and thermal
pollution

5. Sewage
oThe release of wastewater from drains or sewers
•Includes human wastes, soaps, and detergents
oCauses 2 serious environmental problems:
•Enrichment
•Fertilization of a body of water by high levels of plant and
algal nutrients (nitrogen and phosphorus)
•Increase in Biological Oxygen Demand (BOD)
•Amount of oxygen needed by microorganisms to decompose
biological wastes
•As BOD increases Dissolve Oxygen (DO) decreases

6. Sewage

7. Sewage-Eutrophication
oOligotrophic
•Unenriched, clear water that supports small
populations of aquatic organisms

8. Sewage-Eutrophication
oEutrophic-
•Slow-flowing stream, lake or estuary enriched by
inorganic plant and algal nutrients such as
phosphorus
•Often due to fertilizer or sewage runoff

9. Disease-causing Agents
oInfectious organisms that
cause diseases
•Originate in the wastes of
infected individuals
oCommon bacterial or viral
diseases:
•Typhoid, cholera, bacterial
dysentery, polio, and
infectious hepatitis

10. Disease-causing Agents
oMonitored by testing for presence of E. coli in the
water via a fecal coliform test
•Indicates the presence of pathogenic organisms

11. Sediment Pollution
oExcessive amounts of suspended soil particles
•Originates from erosion of agricultural lands, forest soils
exposed by logging, degraded stream banks, overgrazed
rangelands, strip mines, and construction
oProblems
•Limits light penetration
•Covers aquatic animals and plants
•Brings insoluble toxins into waterways

13. Inorganic Plant and Algal
Nutrients
oChemicals such as nitrogen and phosphorus that
stimulate the growth of plants and algae
•Harmful in large concentrations
oSources:
•Human and animal wastes, plant residues, atmospheric
deposition, and fertilizer runoff
oCauses:
•Enrichment, bad odors, and a high BOD

14. Inorganic Plant and Algal Nutrient-
The Dead Zone

16. The Great Pacific
Patch of Garbage

17. Organic Compounds
oChemicals that contain carbon atoms
•Natural examples: sugars, amino acids, and oils
•Human-made examples: pesticides, solvents, industrial
chemicals, and plastics

18. Inorganic Chemicals
oContaminants that contain elements other than
carbon
•Examples: acids, salts, and heavy metals
oDo not degrade easily
oLead
•Found in old paint, industrial pollutants, leaded gasoline
oMercury
•Mercury bioaccumulates in the muscles of top predators
of the open ocean

19. Radioactive Substances
oContain atoms of unstable isotopes that
spontaneously emit radiation
oSources
•Mining
•Processing radioactive materials
•Nuclear power plants
•Natural sources

20. Thermal Pollution
oOccurs when heated water
produced during industrial
processes is released into
waterways
oOrganisms affected
•Temperature affects
reproductive cycles,
digestion rates, and
respiration rates
•Warm water holds less DO
than cold water

21. Water Quality Today
oTwo Types of Water Pollution
o-Point Source Pollution
•water pollution that can be traced to a specific origin
•Discharge via pipes, sewage, and ditches
o-Non-point Source Pollution
•Pollutants that enter bodies of water over large areas
rather than being concentrated at a single point of entry
•Diffuse, but its cumulative effect is very large
•Ex: runoff from agricultural fields or parking lots

22. Water Pollution from Agriculture
oAgriculture is leading source of water pollution in
US
•Animal wastes and plants residues have high BOD
•Chemical pesticides can leach into groundwater
oAlmost all streams and rivers are polluted with
agricultural pesticides

23. Municipal Water Pollution

24. Industrial Wastes in Water
oDifferent industries generate different pollutants
•Food processing plants-high BOD
•Paper mills-High BOD and toxic compounds
oMany industries recover toxins before they go into
the waste stream

25. Case-In-Point Green Chemistry

26. Groundwater Pollution

27. Water Pollution in Other Countries
oLake Maracaibo, Venezuela
•10,000 oil wells tap lake bottom
•Leak oil into lake
•Agricultural wastes
from local fields
•Unit recently raw
human waste
polluted the lake

28. Water Pollution in Other Countries
oPo River, Italy
•Similar to Mississippi River
•Pollutants: Sewage, industrial wastes, sediment
•>16 million Italians depend on the river for drinking
water
•Pollution is high
•Swimming and fishing prohibited
•Cleanup will require a national management plan and
may take decades

29. Water Pollution in Other Countries
oGanges River, India
•Used for bathing and washing
clothing
•Sewage and industrial waste
discharged into river
•Ganga Action Plan initiated by
government
•Construction of 29 sewage
treatment plants

30. Improving Water Quality-
Purification of Drinking Water
oIn US most municipal
water supplies are
treated
oCollected from water
or reservoir
oTreated

31. oTreated water
distributed to
customers
oSewer lines bring
sewage to treatment
plant
oSewage treated at
sewage treatment plant
Improving Water Quality-
Purification of Drinking Water

32. Purification of Drinking Water
oChlorine Dilemma
•Chlorine kills disease causing organisms
•Chlorine byproducts are linked to numerous cancers,
miscarriages and birth defects
•Peru stopped using chlorine
•1991-huge cholera epidemic that infected 300,000 people
oFluoridation
•Prevents tooth decay
•Linked to cancer, kidney disease

33. Municipal Sewage Treatment
oPrimary treatment
•Removing suspended and floating particles by mechanical
processes
oSecondary treatment
•Treating wastewater biologically to decompose suspended organic
material; reduces BOD

34. Municipal Sewage Treatment
oSewage Sludge
•Solids remaining after primary and secondary sewage
treatment has been completed
oTertiary treatment
•Advanced wastewater treatment methods that are
sometimes employed after primary and secondary
treatments
•Reduce phosphorus and nitrogen

35. Municipal Sewage Treatment

36. Individual Septic System-
Septic Tank

37. Individual Septic System-
Drain Field

38. Laws Controlling Water Pollution
oCitizen Watchdogs to Monitor Pollution
oSafe Drinking Water Act (1974)
•Set uniform federal standards for drinking water
•Maximum contaminant level
oClean Water Act (1972)
•EPA sets up and monitors National Emissions
Limitations
•Effectively improved water quality from point sources

39. Laws that Protect Groundwater
oSafe Drinking Water Act
oResource, Conservation and Recovery Act