Acid Rain
Case Study # 6
Presented by: Anna Turo and Dara Barker, November 3, 2006
CHEM 301, Aqueous Environmental Chemistry
Materials Included in Reading Package:
1. Max-Planck Institute of Chemistry, `Compilation of Henry`s Law Constants for
Inorganic and Organic Species of Potential Importance in Environmental Chemistry`,
By Ralph Sander
http://www.mpch-mainz.mpg.de/~sander/res/henry.html
Accessed 02/11/06
2. Parliamentary Research Branch, ‘Acid Rain’, by Alan Nixon and Thomas Curran,
http://dsp-psd.communication.gc.ca/Collection-R/LoPBdP/CIR/7937-e.htm
Accessed 31/10/06
3. Elmhurst College, ‘Acid Rain Effects’, C. Ophardt
http://www.elmhurst.edu/~chm/vchembook/195lakeeffects.html
Accessed 30/10/06
4. Duffy, Stephen J., and vanLoon, Gary W., Environmental Chemistry: A Global
Perspective, 2e, Oxford University Press, New York, 2005 pp. 234, 378
5. Canada.com, Where Perspectives Connect, ‘Acid rain damaging a third of China’,
http://www.canada.com/index.html
Accessed 01/11/06.
Further Resources:
1. Spiro, T. G., and Stigliani, W. M.; Chemistry of the Environment, 2e, Prentice Hall,
New Jersey, 2003
2. Environment Canada, ‘Acid Rain Facts’,
http://www.ec.gc.ca/acidrain/acidfact.html
Accessed 29/10/06
3. Science Clarified, ‘Acid Rain’
http://www.scienceclarified.com/A-Al/Acid-Rain.html
Accessed 30/10/06
4. New Scientist, April 2006, ‘Diversity hotspots face fatal dousing with acid’, by Fred
Pearce,
http://www.newscientistom/channel/earth/mg19025464.100-diversity-hotspots-facefatal-dousing-with-acid.html
Accessed 31/10/06
5.
Rodhe, H., Dentener, F., Schulz, M.; The Global Distribution of Acidifying Wet
Deposition; Environ. Sci. Technol. 2002, 36, 4382-4388.
6. Environmental Education, Kristianstad University
http://www.mna.hkr.se/ene410/
Accessed 01/11/06
7. ‘Partners in Air’
www.partnersinair.org
Accessed 31/10/06
8. The Gazette, June 2006, ‘Acid Rain Levels to Rise’, by Allan Woods.
http://www.canada.com/montrealgazette/news/story.html
Accessed 31/10/06
Figure 1. The Acid Rain Cycle, Causes and Effects.
1.
2.
3.
4.
5.
Emission of toxic gasses.
Transformation to acidic compounds in water droplets and wet deposition.
Acidification of water receiving the acid precipitation.
Direct and indirect damage to vegetation.
Leaching of nutrient cations from topsoils, causing stunted growth and death of
plants.
6. Effects speciation of metals, which can be converted to toxic forms.
Did you know…?
One of the most acidic rainfalls yet recorded fell in Scotland in 1974 and was measured at
2.4 on the pH scale -- roughly the pH of vinegar and over one thousand times as acidic as
natural rain. In December 1982, a sample of fog taken at Corona del Mar in Southern
California had a pH of 1.69.
Table 1. Henry’s Law constants for gases that contribute to acid rain.
KH (M atm-1) at 298 K
Species
NO
1.9 x 10-3
NO2
1.0 x 10-2
HNO2
49
HNO3
2.1 x 105
SO2
1.23
SO3
∞
Table 2. Acid rain species and their pKas
Acidic compound
pKa1
H2SO4
-10
HNO3
-1.5
H2SO3
1.76
HNO2
3.34
H2CO3
6.35
pKa2
1.92
n/a
7.00
n/a
10.31
Table 3. pH Limits for Life in Aquatic Plants and Animals
Animal
pH
Small mouth Bass
6.0-6.5
Lake Trout
5.0-4.5
Brown Trout
5.5-5.0
Yellow Perch
5.0-4.5
Salamander
5.5-5.0
Mussel
6.5-6.0
May Fly
6.0-5.5
Zooplankton
5.0-4.0
Frogs
4.5-4.0
Figure 2. pH/pe Speciation Diagram of Iron. Iron hydroxides dissolve to free iron ions as
pH decreases.
Figure 3. Solubility Speciation Diagram of Aluminum. Total aluminum in solution is
lowest around pH 6 -7.
Figure 4. Mean five year pH of rain from 1980-1984
Figure 5. Mean five year pH of rain from 1996-2000
Acid rain damaging a third of China
Acid rain caused by sulphur dioxide spewed from factories and power plants affected a
third of China's vast land mass last year, posing a threat to public health and food safety.
BEIJING -- One-third of China's vast landmass is suffering from acid rain caused by its rapid
industrial growth, while local leaders are failing to enforce environmental standards for fear of
hurting business, said officials quoted Sunday by state media.
China's factories spewed out 25.5 million tons of sulphur dioxide -- the chemical that causes acid
rain -- last year, up 27 percent from 2000, said Sheng Huaren, deputy chairman of the Standing
Committee of parliament.
Sheng released a report Saturday that found pollution from factories and power plants was rising
by 9 percent a year -- an embarrassment for a government that promised this year to clean up
China's air. The report said sulphur dioxide emissions were double safe levels.
"Increased sulphur dioxide emissions meant that one-third of China's territory was affected by
acid rain, posing a major threat to soil and food safety," Sheng said, according to the governmentowned Xinhua News Agency and newspapers.
Environmental protection has become a prominent issue in China following a string of industrial
accidents that poisoned major rivers, forcing several cities to shut down their water systems.
Chinese cities are among the world's smoggiest following two decades of breakneck economic
growth. The Chinese government says all of China's major rivers are dangerously polluted.
Millions of people lack access to clean drinking water.
Premier Wen Jiabao publicly criticized officials in April after the government revealed it failed to
meet most of its targets over the past five years in environmental areas ranging from containing
pollution to stopping the loss of farmland. Wen said officials would be held personally
responsible for future environmental disasters.
The government pledged this year to cut air pollution emissions by 10 percent by 2010.
Beijing plans to spend $175 billion on environmental protection over the next five years, up 60
percent from the previous five years, according to Mao Rupai, chairman of the parliament's
environmental committee.
Lawmakers are considering raising fines for environmental violators in order to encourage
companies to spend more on clean technology, Mao said at a news conference on Saturday.
Mao complained that local officials fail to enforce standards for fear of hurting businesses. He
said some areas comply with as few as 30 percent of environmental regulations.
"It is true that in some areas, local governments focus more on economic development than on the
environment," he said. "In the future, officials will be judged not just by their economic growth
but by environmental protection as well."
© Associated Press 2006