Page 211 - Fundamentals of Air Pollution

Questions .177

processes of oxidation transform gases into more highly oxidized products,
e.g., NO to NO 2 to HNO 3, hydrocarbons to aldehydes, and SO 2 to sulfate
particles. The removal of material from the atmosphere involves two pro-
cesses: wet and dry deposition. The water solubility of gases influences
the extent of removal by wet versus dry deposition. Gases such as SO 2 and
NO 2 are sufficiently soluble to dissolve in water associated with in-cloud
formation of rain droplets. These soluble gases may be removed by wet
deposition of liquid droplets in the form of rain or fog. Less soluble gases
such as O 3 and hydrocarbon vapors are removed by transport to the surface
of the earth, where they diffuse to vegetation, materials, or water bodies
(see Chapter 10),

REFERENCES

1. Pitts, J. N., Jr., Winer, A. M., Darnall, K. R., Lloyd, A. C, and Doyle, G. J., in "Proceed-
ings, International Conference on Photochemical Oxidant Pollution and Its Control," Vol.
II (B. Dimitriades, ed.), EPA-600/3-77-OOlb, pp. 687-707. U.S. Environmental Protection
Agency, Research Triangle Park, NC, 1977.
2. Carter, W. P. L., "Development of Ozone Reactivity Scales for Volatile Organic Com-
pounds," EPA 600/3-91-050. U.S. Environmental Protection Agency, August 1991.
3. National Research Council, "Ozone and Other Photochemical Oxidants." National Acad-
emy of Sciences, Washington, DC, 1977.
4. Campbell, I. M., "Energy and the Atmosphere." Wiley, New York, 1977.
5. Lonneman, W. A., Seila, R. L., and Bufalini, J. J., Environ. Sci. Technol. 12,459-463 (1978).
6. Data obtained from the 1976 data file of the Regional Air Pollution Study Program. U.S.
Environmental Protection Agency, Research Triangle Park, NC, 1976.
7. Akimoto, H., Sakamaki, F., Hoshino, M., Inoue, G., and Oduda, M., Environ. Sci. Technol.
13, 53-58 (1979).
8. Graedel, T. E., Hawkins, D. T., and Claxton, L. D., "Atmospheric Chemical Compounds:
Sources, Occurrence, and Bioassay," Academic Press, Orlando, FL, 1986.
9. Atkinson, R., and Lloyd, A. C., /. Phys. Chem. Ref. Data 13, 315-444 (1984).
10. Calvert, J. G., Su, F., Bottenheim, J. W., and Strausz, O. P., Atmos. Environ. 12, 197-226
(1978).

SUGGESTED READING

National Research Council, "Rethinking the Ozone Problem in Urban and Regional Air Pollu-
tion." National Academy Press, Washington, DC, 1991.
Sloane, C. S., and Tesche, T. W., "Atmospheric Chemistry: Models and Predictions for Climate
and Air Quality." Lewis Publishers, Chelsea, MI, 1991.
Warneck, P., "Chemistry of the Natural Atmosphere." Academic Press, San Diego, 1988.

QUESTIONS

1. What wavelength band of solar radiation leads to photodissociation for nitrogen dioxide?
What determines the lower limit?