Nitrogen Oxides in the Atmosphere

Since the chemiluminescence detector system depends on the reaction of O3 with NO, it is necessary to convert NO2 to NO in the sample prior to analysis. This is accomplished by passing 

This analysis techniqne is illnstrative of chemiluminescence analysis in general. Chemiluminescence is an inherently desirable technique for the analysis of atmospheric pollutants because it avoids wet chemistry, is basically simple, and lends itself well to continuous monitoring and instrumental methods. Another chemiluminescence method, which is employed for the analysis of ozone, is described Section 18.20.5. 

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Figure 7.2 Acid rain occurs when water comes into contact with sulfur and nitrogen oxides in the atmosphere, which can come from natural sources or from man-made sources like cars or power plants. These acid rain-damaged coniferous trees live in the Karkonosze National Park in Silesia, Poland.

The best way to prevent these problems is to prevent acid rain at the start. Reducing emissions from automobiles and power plants would help reduce acid-rain levels. This means conserving energy and driving less. The less energy people use, the less coal needs to be burned to produce electricity. These measures help decrease the sulfur and nitrogen oxides in the atmosphere and, therefore, decrease the amount of acid rain. 

Ambient Air. Hanst, et al (42) showed that dimethylamine could react with nitrogen oxides in the atmosphere to form N-nitrosodimethylamine. Fine, et al (39) in studies in New York City, Boston and upstate New Jersey, found little evidence to suggest that NDMA or other N-nitroso comf>ounds were being formed in the atmosphere, even in the neighborhood of amine factories. NDMA was found sporadically, in only 3 out of 40 sites. 

Calvert, J. G., and W. R. Stockwell, Mechanism and Rates of the Gas Phase Oxidations of Sulfur Dioxide and Nitrogen Oxides in the Atmosphere, in S02, NO and N02 Oxidation Mechanisms Atmospheric Considerations (J. G. Calvert, Ed.), Acid Precipitation Series, Vol. 3, pp. 1-62 (J. I. Teasley, Series Editor), Butterworth, Stoneham, MA, 1984. 

Calvert, J. G. Stockwell, W. R. Mechanism and rates of the gas-phase oxidations of sulfur dioxide and nitrogen oxides in the atmosphere. In S02> NO and NO2 Oxidation Mechanisms Atmospheric Considerations Calvert, J. G., Ed. Butterworth Boston, 1984 pp. 1-62. 

When organic fuels are burned, carbon dioxide and water vapor are released along with various amounts of sulfur dioxide and nitrogen oxides. The sulfur and nitrogen oxides in the atmosphere are then further oxidized with the assistance of ultraviolet solar radiation when these gases are scrubbed from the air by precipitation, a dilute solution of sulfuric acid and nitric acid forms. Carbon dioxide itself hydrolyzes to carbonic acid and is important in the marine carbonate buffer system however, it is a weak organic acid and atmospheric concentrations typically lower the pH of distilled water only to about 5.7 (5-6). 

Figure 5. Pattern of possible transformations and migration of sulphur and nitrogen oxides in the atmosphere of the region investigated.

The major source of nitrogen oxides in the atmosphere is automobiles. 

Dignon, J., and Penner, J. E., Biomass burning A source of nitrogen oxides in the atmosphere. In Global Biomass Burning (J. Levine, ed.), p. 370. MIT Press, Cambridge, MA, 1991. 

Nitrogen oxides in the atmosphere may acidify rainwater. Write the equilibrium expression for the following reaction, in which gaseous nitrous acid forms in the atmosphere ... 

Acids other than sulfuric acid can also be involved in the modification of sea-salt particles. The most common such acid is nitric acid formed by reactions of nitrogen oxides in the atmosphere. Traces of nitrate salts may be found among sea-salt particles. 

The emission of sulfur and nitrogen oxides and particulates from coal combustion has become a problem of increasing concern and regulation. The combustion of coal contributes about 25 percent of the particulate matter, 25 percent of the sulfur oxides, and 5 percent of the nitrogen oxides in the atmosphere. A major concern about the particulate matter, most of which is inorganic matter derived from the mineral content of... 

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