ACID RAIN
How does it form?
Where is this a problem?
What does it do to ecosystems and people?
ACID DEPOSITION FORMATION:
SECONDARY OR PRIMARY POLLUTANT?
SOURCES FOR PRECURSORS?
TRANSPORTATION? WET OR DRY DEPOSITION?
FORMULAS YOU NEED TO MEMORIZE:
SO3
+ H2O  H2SO4 (sulfuric acid)
NOx + H2O  2HNO3 (nitric acid)
These
are two forms (flavors)
of acid deposition.
Normal rain
 CO2

+ H2O  H2CO3 (carbonic acid)
Normal rain is always slightly acidic!
THIS
IS NOT ACID RAIN!!!
THIS IS NOT POLLUTION!!!!
Acid
rain < pH 5.6
OBSERVATIONS?
IS ACID RAIN A BIG PROBLEM IN HOUSTON?
WHERE IS ACID RAIN A BIG CONCERN?
GLOBAL ACID RAIN AREAS OF CONCERN
EFFECTS ON TERRESTRIAL SYSTEMS:
Direct damage to leaves
and roots
Weak trees are susceptible
to insects and disease
ACID DEPOSITION LEACHES NUTRIENTS FROM
SOIL AND MAKES TOXINS (AL3+) MORE SOLUBLE
EFFECTS ON AQUATIC ECOSYSTEMS

Loss of biodiversity
Range of tolerance
 Jelly-like fish eggs broken down
 Acidity denatures enzymes

Acid shock – sudden increase in acidity, often in
spring can cause fish kills
 Aluminum ions (Al3+) are released from lake
bed, suffocating fish
 Below pH4.5, lakes devoid of fish

CULTURAL EFFECTS OF ACID RAIN
Marble and limestone
Acid breaks down these
basic materials
MANY FAMOUS BUILDINGS ARE BEING
DAMAGED
Taj Mahal
Parthenon
Statue of liberty
Loss of artistic detail in
Acropolis
HUMAN HEALTH EFFECTS OF ACID RAIN

Contributes to bronchitis and asthma
ACID RAIN: CHECK FOR
UNDERSTANDING!
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How does acid rain form?
What is the pH of acid rain?
Why is rain normally acidic?
Why is this a bigger problem on the East Coast than
here?
Why is acid rain “like AIDS for plants”?
Why are there more significant effects on aquatic
systems than on terrestrial systems?
IF YOU’RE NOT PART OF THE
SOLUTION, YOU’RE PART OF THE
PRECIPITATE.
Solutions to Air pollution
1994
1999
2007
TWO STRATEGIES
 Pollution
prevention
(don’t create the
primary pollutants
in the first place)
 Pollution
clean up
(now that they’re in
the environment,
let’s mitigate the
effects)
LEGAL SOLUTIONS
Emissions trading policy (Cap and Trade):
stationary pollution sources can buy, sell and
trade the right to pollute.
 This policy ONLY exists in the US for SOx right
now.
 (CO2 cap and trade just started in California last
year!)

TECHNOLOGY STRATEGIES: TRAP POLLUTANTS AT THE
SOURCE
TECHNOLOGY SOLUTION:
VEHICLE EFFICIENCY



Using less gas = fewer
combustion pollutants
Hybrids use friction
from breaking to charge
electric battery
“regenerative breaking”
Computer switches
engine from gas to
electricity.
IMPROVED
CHEVY VOLT 2011 – POLLUTION
DIVERTED TO POWER PLANT
TECHNOLOGY SOLUTION:
COAL/COAL GASIFICATION
 Burn
low-sulfur coal
from Western US
 Gasification turns
solid coal to gas
before it is burned –
fewer particulates,
SOx
BURN CLEANER
“LIMING” A LAKE (POWDERED
LIMESTONE)
STREAM DOSER
 Spot
the pipe which
adds the limestone
solution to the
stream!
I=PAT
I = clean air
 P = growing
 A = options?
 T = options?
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Which of these can YOU do TODAY? 