Transcript Acid Rain - Downtown Magnets High School

Acid Deposition
Measuring
Acidity
• pH scale
(log scale)
• 0-6: acid,
7: neutral,
8-14: base
Normal Rain
Water
•pH of 5-6
•Due to CO2
+ H 2O 
H2CO3
(carbonic
acid)
Acid Rain pH
• pH is a 3-4
Acid Dep. from SO2
• SO2: Coal combustion from
power utilities.
• SO2 + H2O --->H2SO4
(Sulfuric acid)
Acid Dep. from NO2
• NO2: Gasoline combustion and
fertilizer application
• NO2 + H2O --->HNO3- (Nitric acid)
Terrance’s
Future
Wife…
Effects of Acid
Deposition
Destroys Limestone!
Before
After
An
extra
hole…
Fish Deaths
• Acid in lakes  declining fish
pops
• Can only tolerate certain pH
ranges.
Hmm…
Dinner!
Plant Deaths
• Acid in soils  declining agricultural
productivity
• Plants can only tolerate certain pH
ranges too!
Tree Damage
External damage to bark & leaves
Little resistance to pests
Lower rate of photosynthesis
In Rivers and Oceans
• Metals become ionic at lower pH 
taken up via ion channels of fish gills
(Hg+2 /K+)
 Metal accumulation in food web 
metal toxicity in fish
Plant Metal Toxicity
• If metals sit in ground 
taken up by plants (plant
metal toxicity)
Soil Leaching
• If it rains after acid breaks up metals
into ions, then metals leave soil (soil
leaching).  Loss of nutrients
Changes
in Rain
pH
Why
East
Coast?
Controlling Acid Deposition
Reduce SO2 and NO2
emissions  Switch to
alternative energies (solar,
hydroelectric)
• Legislation: Clean Air Act
 Set standards on how much NO2
and SO2 are allowed to be emitted
(NAAQS).