Impact of Technologies on Hydrosphere and Lithosphere

1
Impact of Technologies on Hydrosphere and
Lithosphere

• Agrichemicals, Acid Mine Drainage, Oil Spills,
  Solid Waste Disposal, Landfills, Soil Erosion,
  and Desertification

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Distribution of Water on Earth
Nebel/Wright, Environmental Science, 7th,
Prentice Hall, NJ, 2000, 415
3
Water Cycle
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 90
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http//library.thinkquest.org/C0111040/Types/water
.php
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http//library.thinkquest.org/C0111040/Types/water
.php
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http//library.thinkquest.org/C0111040/Types/water
.php
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http//library.thinkquest.org/C0111040/Types/water
.php
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http//library.thinkquest.org/C0111040/Types/water
.php
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Agrichemicals

• Pesticides and fertilizers can contaminate
  drinking water supplies
  
• Pesticides are frequently non-polar molecules
  which are not water soluble, but can contaminate
  surface waters
  
• Fertilizers are water soluble ionic substances
  that can contaminate ground waters - blue babies
  from NO3-

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Acid Mine Drainage

• Acid Mine Drainage (AMD) is the number one
  environmental problem facing the mining industry
  
  
• Devastates fish and aquatic habitat
• Is virtually impossible to reverse with existing
  technology and once started, costs millions of
  dollars annually to treat and can continue for
  centuries

http//emcbc.miningwatch.org/emcbc/primer/acid_min
e_drainage.htm
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Continued...

• Ore is mineralized rock containing a valued
  substance such as gold, or coal
  
• Open-pit mining involves the excavation of large
  quantities of waste rock (material not containing
  the target mineral) in order to extract the
  desired mineral ore

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Continued...

• The ore is then crushed into finely ground
  tailings for processing with various chemicals
  and separating processes to extract the final
  product
• Canadian mineral industry generates one million
  tonnes of waste rock and 950,000 tonnes of
  tailings per day, or 650 million tonnes of waste
  per year

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Continued...

• After being removed, waste rock, which often
  contains acid-generating sulfides, heavy metals,
  and other contaminants, is usually stored above
  ground in large free-draining piles
• Sulfide ores undergo reaction with air to produce
  acid mine drainage (AMD)

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Acid Mine Drainage - "Yellow Boy"
FeS2 15/4 O2 7/2 H2O -- 2H2SO4 Fe(OH) 3
http//www.science.uwaterloo.ca/research/ggr/MineW
asteGeochemistry/AcidMineDrainage.html
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Continued...

• After the waste rock is removed and ore is
  extracted, ore is processed to separate the
  target mineral
  
• Mine tailings often contain the same toxic heavy
  metals and acid-forming minerals that waste rock
  does plus chemical agents used to process the
  ores, such as cyanide or sulphuric acid

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Continued...

• If improperly secured, contaminants in mine waste
  can leach out into surface and groundwater
  resulting in long-term pollution
  
• Roman mine sites in Great Britain continue to
  generate acid drainage 2,000 years after mining
  ceased

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Heap Leaching in Gold Mining

• Allows gold production from ore bodies once
  considered too meager to mine
  
• Crushed ore or gold-mine tailings are piled up
  (150 ft high) on top of a synthetic liner and
  then sprayed repeatedly with a cyanide solution
  (75 gallons/day/ ft2)

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Continued...

• The cyanide solution trickles through the ore,
  bonding to the gold and other metals, and then
  sinks to the bottom of the heap
  
• There it flows into collection ponds, after which
  the gold is recovered from the solution by
  adsorption onto carbon

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Continued...

• the resulting pools of cyanide kill thousands of
  migratory birds that drink from them
  
• Leaks from these pools also contam-inate
  groundwater and exposes humans
  
• Sub-lethal exposure to CN over time causes
  problems with breathing, nervous system, and the
  digestive tract

http//www.miningwatch.org/emcbc/publications/amd_
water.htmHeap
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Oil Spills

• The United States uses about 700 million gallons
  of oil every day and the world uses nearly 3
  billion gallons each day
  
• Oil spills into rivers, bays, or oceans are
  usually caused by accidents involving tankers,
  barges, pipelines, refineries, and storage
  facilities

http//response.restoration.noaa.gov/kids/spills.h
tml
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Continued...

• Oil floats on salt water (the ocean) and usually
  floats on fresh water (rivers and lakes)
  
• Oil usually spreads out rapidly across the water
  surface to form a thin layer (oil slick)
  
• Oil spills are very harmful to marine birds and
  mammals, fish and shellfish

http//response.restoration.noaa.gov/kids/spills.h
tml
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http//library.thinkquest.org/C0111040/Types/land.
php
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Solid Waste Disposal

• One of the major problems associated with
  urbanization is the disposal of solid waste
  
• Waste disposal generally falls into two
  categories (a) throwaway methods, like
  incineration, landfilling, and ocean dumping, and
  (b) low-waste methods, like recycling and
  composting

http//www.globalchange.umich.edu/globalchange2/cu
rrent/lectures/urban2/urban_indust.htmlsolid_wast
e
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Continued...

• Incineration produces air pollution, while
  landfills give off gases that contribute to
  global warming, and pollute ground water
  supplies
• Landfills provide a ready dumping ground for
  non-hazardous waste, but these spaces are running
  out

http//www.globalchange.umich.edu/globalchange2/cu
rrent/lectures/urban2/urban_indust.htmlsolid_wast
e
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Continued...

• Each year 5.2 million people die from diseases
  caused by improper disposal of sewage and solid
  waste
  
• It is projected that by the year 2025 quantities
  of urban waste will increase four to five fold

http//www.globalchange.umich.edu/globalchange2/cu
rrent/lectures/urban2/urban_indust.htmlsolid_wast
e
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http//people.howstuffworks.com/landfill2.htm
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Landfill

• Landfill - carefully designed structure built
  into or on top of the ground in which trash is
  isolated with a bottom liner (clay or plastic)
  and daily covering of soil, from the surrounding
  environment (groundwater, air, rain)
• Landfills are not designed to break down trash,
  merely to bury it

http//people.howstuffworks.com/landfill3.htm
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http//people.howstuffworks.com/landfill1.htm
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Landfills in the Long-term
When a landfill closes, the site, especially the
groundwater, must be monitored and maintained for
up to 30 years!
http//people.howstuffworks.com/landfill7.htm
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Soil Erosion and Desertification

• Soil erosion - farming techniques allow wind and
  rain to carry away about 25 billion tons of top
  soil/yr - estimated all top soil will be lost by
  2050. Loss of productivity is currently being
  compensated by fertilizers/pesticides
• Desertification-overgrazing/overfarming change
  marginal lands into deserts