Effects of pH Change in Precipitation

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Effects of pH Change in Precipitation

• Acid Deposition
• http//www.natgeoeducationvideo.com/film/1233/acid
  -rain

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Acid Deposition

• Air pollution is one of several interacting
  stresses that can damage, weaken, or kill trees
  and pollute surface and groundwater.
• Acid deposition consists of rain, snow, dust, or
  gas with a pH lower than 5.6.
• As of 2010, the most acidic rain falling in the
  US has a pH of about 4.3

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Emissions
SO2
NOx
Acid deposition
H2O2
O3
Others
PANs
Susceptibility to drought, extreme cold, insects,
mosses, disease organisms
Reduced photo-synthesis and growth
Direct damage to leaves bark
Soil acidification
Tree death
Root damage
Reduced nutrient water uptake
Leaching of soil nutrients
Release of toxic metal ions
Acids
Lake
Groundwater
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Acid Deposition

• Sulfur dioxides, nitrogen oxides, and
  particulates can react in the atmosphere to
  produce acidic chemicals that can travel long
  distances before returning to the earths
  surface.
• Tall smokestacks reduce local air pollution but
  can increase regional air pollution.

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Acid Deposition

• Two main contributors to acid deposition
• Sulfur Dioxide (SO2)
• Nitrogen Oxides (NOx)
• 66 of all sulfur dioxides and 25 of all
  nitrogen oxides comes from electric power
  generation that produces energy by burning fossil
  fuels.

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Acid Deposition

• Acidic water flows over and through the ground
  which affects a variety of plants and animals
• Dry deposition refers to acidic gases and
  particles.
• About half of the acidity in the atmosphere falls
  back to earth through dry deposition.
• The wind blows these acidic particles and gases
  onto/into buildings, cars, homes, and trees

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Acid Deposition

• Acidic water dissolves the nutrients and helpful
  minerals in the soil
• It washes nutrients away before plants can use
  them to grow
• Acid rain also causes the release of substances,
  such as aluminum, that are toxic to plants

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Acid Deposition
Germany

• Acid rain does not usually kill trees directly
• Weakens trees
• Damages leaves
• Limits nutrients available
• Toxic substances are slowly released from the
  soil.

South Carolina
Mongolia
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Acid Deposition

• Acid Deposition can release aluminum from lake
  sediments which, in turn, adversely affects the
  gills of fish.
• Generally, the young of most species are more
  sensitive to environmental conditions than
  adults.
• At pH 5, most fish eggs cannot hatch.
• At lower pH levels, some adult fish die.
• Chronic stress leads to lower body weight and
  smaller size
• Some acid lakes have no fish.

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Acid Deposition

• During the 1970s and 1980s, many lakes in
  Canada and the Northeastern U.S. lost all of
  their fish due to lowered pH levels

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Acid Deposition
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Acid Deposition

• pH measurements in relation to major coal-burning
  and industrial plants.

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Acid Deposition
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Acid Deposition

• Antiquities can be destroyed by acid deposition

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Acid Deposition

• Lime (calcium carbonate) can be deposited into a
  lake to increase the pH

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Hubbard Brook Experimental Forest
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ACID DEPOSITION

• Acid deposition contributes to chronic
  respiratory disease and can leach toxic metals
  (such as lead and mercury) from soils and rocks
  into acidic lakes used as sources for drinking
  water.

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Solutions
Acid Deposition
Prevention
Cleanup
Reduce air pollution by improving energy
efficiency
Add lime to neutralize acidified lakes
Reduce coal use
Add phosphate fertilizer to neutralize acidified
lakes
Increase natural gas use
Increase use of renewable energy resources
Burn low-sulfur coal
Remove SO2 particulates NOx from smokestack
gases
Remove NOx from motor vehicular exhaust
Tax emissions of SO2