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Water Pollution

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Title: Water Pollution


1
Chapter 14 Water Pollution
2
Water Pollution
  • Water pollution- the contamination of streams,
    rivers, lakes, oceans, or groundwater with
    substances produced through human activities and
    that negatively affect organisms.
  • Point sources- distinct locations that pump waste
    into a waterway. These are easily identified
  • Nonpoint sources- diffuse areas such as an entire
    farming region that pollutes a waterway. These
    are more expensive and difficult to clean up.

3
Can you identify which of these is point
source Pollution?
4
Categories of Water Pollution
  • Sewage
  • disease-causing agents
  • sediment pollution
  • inorganic plant and algal nutrients
  • organic compounds
  • inorganic chemicals
  • radioactive substances
  • thermal pollution
  • Noise pollution

5
Water Pollution is a Problem Worldwide
Half of the worlds major rivers are seriously
depleted and polluted They poison surrounding
ecosystems Threaten the health and livelihood of
people The invisible pollution of groundwater has
been called a covert crisis
6
Water Pollution
  • Over two-thirds of U.S. estuaries and bays are
    severely degraded because of nitrogen and
    phosphorous pollution
  • Every year almost 25 of U.S. beaches are closed
    at least once because of water pollution
  • Over 73 different kinds of pesticides have been
    found in the groundwater that we eventually use
    to drink
  • 1.2 trillion gallons of sewage, storm water and
    industrial waste are discharged into U.S. waters
    every year
  • A large number of U.S. rivers are too polluted
    for aquatic life to survive
  • Americans use over 2.2 billion pounds of
    pesticides every year, which eventually washes
    into our rivers and lakes

7
Leading causes of water pollution
  • Agriculture activities
  • Sediment eroded from the lands
  • Fertilizers and pesticides-almost all waters are
    polluted with pesticides
  • Bacteria from livestock and food processing
    wastes
  • Industrial facilities- heavy metals, corrosive
    materials organic and non-organic chemicals
  • Mining- acid drainage pollutes water by leeching
    out heavy metals

8
Agriculture major source of water pollution
  • Agriculture is leading source of water pollution
    in US
  • Animal wastes and plants residues have high BOD
  • Chemical pesticides can leach into groundwater
  • Almost all streams and rivers are polluted with
    agricultural pesticides

9
Agricultural Runoff is the main cause of the Dead
Zone in the Gulf of Mexico The U.N. documented
250 dead zones worldwide in 2005
10
Sediment runoff from farmland is the
highest Pollution from agriculture by weight.
11
Eutrophication
  • Eutrophication is an abundance of fertility to a
    body of water.
  • Eutrophication is caused by an increase in
    nutrients, such as fertilizers.
  • Eutrophication can cause a rapid growth of algae
    which eventually dies, causing the microbes to
    increase the BOD and oxygen levels to fall
    eventually may cause a die-off of all organisms.

12
Solutions to Reduce Eutrophication
  • Phosphate-free detergents
  • Planting vegetation to increase nutrient uptake
  • Treat wastewater
  • Reduce fertilizer application

13
Different industries add different pollutants
  • Food processing plants- high BOD
  • Paper mills- High BOD and toxic compounds
  • Textile industry-the World Bank estimates that
    17-20 percent of industrial pollution comes from
    textile industry with 72 toxic chemicals being
    added to water

14
According to Greenpeace, the discharge from these
factories includes heavy metals and hazardous
and persistent chemicals with hormone-disrupting
properties were found being discharged from
China s factories
15
Heavy Metals and Other Substances that can
threaten human Health and the Environment
  • Lead
  • Arsenic
  • Mercury
  • Acids
  • Synthetic compounds (pesticides, pharmaceuticals,
    and hormones)

16
More on heavy metals
  • Lead
  • Found in old paint, industrial pollutants, leaded
    gasoline
  • Mercury
  • Mercury bioaccumulates in the muscles of top
    predators of the open ocean

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18
Arsenic found naturally in rocks and water
  • When arsenic is found in water, it may be from
    natural causes
  • Highest levels of arsenic in U.S. found in upper
    Midwest and West
  • Individual wells dug in Southeast Asia-many are
    contaminated by arsenic causing arsenic posioning

19
World Mercury Production from Human Activities
20
Pharmaceuticals and Hormones Found in Water
21
Industrial Compounds
  • Chemicals used in manufacturing
  • Local examples include PCBs in Hudson River from
    General Electric Co. and cadmium from foundry in
    Cold Spring
  • PCBs cause brain damage, are lethal and
    carcinogenic

22
Oil Pollution
23
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24
Marine pollution threatens resources
  • Even into the mid-20th century, coastal U.S.
    cities dumped trash and untreated sewage along
    their shores
  • Oil, plastic, chemicals, excess nutrients make
    their way from land into oceans
  • Raw sewage and trash from cruise ships
  • Abandoned fishing gear from fishing boats

In 2006, 359,000 Ocean Conservancy volunteers
from 66 nations picked up 3.2 million kg (7
million lbs.) of trash
25
Ways to Remediate Oil Pollution
  • Containment using booms to keep the floating oil
    from spreading.
  • Chemicals that help break up the oil, making it
    disperse before it hits the shoreline.
  • Bacteria that are genetically engineered to
    consume oil

26
Water Pollution from Mining
  • Acid Mine Drainage-low pH of water causes iron to
    precipitate from pyrite and cause a rusty red
    color
  • Heavy metal contamination and leeching
  • Mine waste and tailings
  • Processing chemicals pollution
  • Sedimentation of waters and erosion

27
Mining often pollutes waters
28
Other Water Pollutants
  • Solid waste pollution (garbage)
  • Sediment pollution (sand, silt and clay)
  • Thermal pollution
  • Radioactive pollution
  • Noise pollution

29
Solid Waste Pollution
  • Much solid waste is garbage
  • North Pacific Gyre-Great Pacific Garbage Patch
  • Plastic waste is dangerous to marine animals and
    humans
  • Found in the stomachs of dead baby sea birds as
    parent birds think the small pieces of plastic is
    phytoplankton.

30
Plastic rubbish deposits
31
Plastic Pollution of Water
  • Plastics can release harmful chemicals into the
    water
  • Plastic is a synthesized organic compound
    (carbon-hydrogen bonds) that does not decompose
  • Plastic breaks up into extremely tiny pieces that
    is mistaken for food by many organisms.

32
Sediment Pollution
  • Excessive 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
  • Problems
  • Limits light penetration
  • Covers aquatic animals and plants
  • Brings insoluble toxins into waterways

33
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34
Land disturbance results in poor water quality
Clear-cutting, mining, poor cultivation
practices Dramatically changes aquatic habitats,
and fish may not survive Solutions better
management of farms and forests avoid
large-scale disturbance of vegetation
35
Radioactive Substances
  • Contain atoms of unstable isotopes that
    spontaneously emit radiation
  • Sources
  • Mining
  • Processing radioactive materials
  • Nuclear power plants
  • Natural sources

36
Thermal Pollution
  • Occurs when heated water produced during
    industrial processes is released into waterways
  • Temperature affects digestive rates, heart rates,
    and respiration rates
  • Warmer water holds less dissolved oxygen
  • Removing streamside cover also raises water
    temperature

37
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38
Noise Pollution
  • Sounds from ships and submarines
  • Sonar equipment could negatively affect whales,
    causing them to be beached
  • U. S. Military exempt from environmental laws
    related to sonar use

39
Organic Compounds found in Polluted Water
40
Human Wastewater
  • Water produced by human activities such as human
    sewage from toilets and gray water from bathing
    and washing clothes or dishes.

41
Why human and animal waste water needs to be
treated
Pathogens and toxins enter water supply via
inadequately treated human waste and animal waste
via feedlots Causes more human health problems
than any other type of water pollution
42
Three reasons scientists are concerned about
human wastewater
  • Oxygen-demanding wastes like bacteria that put a
    large demand for oxygen in the water
  • Nutrients that are released from wastewater
    decomposition can make the water more fertile
    causing eutrophication
  • Wastewater can carry a wide variety of
    disease-causing organisms.

43
Biochemical Oxygen Demand (BOD)
  • BOD- the amount of oxygen a quantity of water
    uses over a period of time at a specific
    temperature.
  • As BOD increases Dissolved Oxygen (DO) decreases
  • Lower BOD values indicate the water is less
    polluted and higher BOD values indicate it is
    more polluted by wastewater.

44
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45
Sewage and pollutants in drinking water
Currently, 1.1 billion people are without safe
drinking water 2.4 billion have no sewer or
sanitary facilities Mostly rural Asians and
Africans An estimated 1.6 to 5 million people
die per year from unsafe drinking water
46
Common Diseases from Human Wastewater
47
Major Water Pollutants and Their Sources
Table 20-1, p. 532
48
Solutions
  • Treat sewage
  • Disinfect drinking water
  • Public education to encourage personal hygiene
  • Government enforcement of regulations

49
Treatments for Human and Animal Wastewater
  • Septic systems- a large container that receives
    wastewater from the house.

50
Treatments for Human and Animal Wastewater
  • Sewage Treatment Plants- centralized plants in
    areas with large populations that receive
    wastewater via a network of underground pipes.
  • Test for human and animal waste using fecal
    coliform bacteria test

51
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52
Levels of Treatment and Success
  • Primary treatment Some pathogenic bacteria and
    some solids removed
  • Secondary treatment some viruses, more waste
    solids, more pathogenic bacteria, and some
    dissolved organics removed, BOD lowered
  • Tertiary treatment Phosphorous and nitrogen
    levels lowered, dissolved organics and pathogenic
    bacteria lowered, waste solids completely removed
  • Chlorination treatment Pathogenic bacteria
    completely removed, nitrogen amounts lowered
    further, viruses lowered further

53
Tertiary treatment of waste water often includes
Chlorine treatment
  • Chlorine Dilemma
  • Chlorine byproducts are linked to numerous
    cancers, miscarriages and birth defects
  • Peru stopped using chlorine
  • 1991 huge cholera epidemic that infected 300,000
    people
  • Fluoridation
  • Prevents tooth decay
  • Linked to cancer, kidney disease

54
Treatments for Human and Animal Wastewater
  • Manure lagoons- large, human-made ponds line with
    rubber to prevent the manure from leaking into
    the groundwater. After the manure is broken down
    by bacteria, it is spread onto fields as
    fertilizers.

55
Problems with Manure Lagoons
  • Containment of lagoons may burst if containment
    walls break.
  • During high precipitation events lagoons may
    overflow bringing pathogenic bacteria to water
    supply

56
We have better methods- We can improve
traditional sewage treatment
  • Use of natural wetlands
  • Remove toxic wastes before sewage enters
    treatment plants
  • Use composting toilets
  • Reduce use of toxic materials

57
Using Nature to Purify our waste water and sewage
water
  • Natural water purification system
  • Sewage flows into anaerobic digester
  • Cleaner water then passes through artificial
    marsh to remove some nutrients
  • water flows into a passive greenhouse
  • Solar energy and natural processes remove and
    recycle nutrients
  • Diversity of organisms used

58
Use of a Living Machine to purify waste water
Omega Center in Rhinebeck NY
59
Water Laws
  • Clean Water Act- (1972) supports the protection
    and propagation of fish, shellfish, and wildlife
    and recreation in and on the water.
  • Issued water quality standards that defined
    acceptable limits of various pollutants in U.S.
    waterways.
  • Effectively improved water quality from point
    sources

60
Water Laws
  • Safe Drinking Water Act- (1974, 1986, 1996) sets
    the national standards for safe drinking water.
  • It is responsible for establishing maximum
    contaminant levels (MCL) for 77 different
    elements or substances in both surface water and
    groundwater.

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63
Indicators of water quality
  • Scientists measure properties of water to
    characterize its quality
  • Biological indicators presence of fecal coliform
    bacteria and other disease-causing organisms
  • Chemical indicators pH, nutrient concentration,
    taste, odor, hardness, dissolved oxygen
  • Physical indicators turbidity, color,
    temperature

64
Streams Can Cleanse Themselves If We Do Not
Overload Them
  • Dilution of pollutants does help
  • Biodegrading of wastes by bacteria (takes time)
    Some substances are not biodegradable
  • Higher human population stresses natural system
    of cleansing
  • Prevention is less costly and more effective and
    cleanup

65
Dilution and Decay of Degradable,
Oxygen-Demanding Wastes in a Stream
Fig. 20-7, p. 534
66
Solutions Methods for Preventing and Reducing
Water Pollution
67
What Can You Do? Reducing Water Pollution
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