Air pollution by nitrogen oxides

Air Pollution by Nitrogen Oxides edited by T. Schneider and L. Grant... 

A.E.R.Budd and M. Wyatt Air Pollution by Nitrogen Oxides, Eds. T.Sneider and L. Grant, Elsevier, Amsterdam, 871... 

Atmospheric Pollution 1982 edited by M.M. Benarie Air Pollution by Nitrogen Oxides edited by T. Schneider and L. Grant Environmental Radioanalysis by H.A. Das, A. Faanhof and H.A. van der Sloot Chemistry for Protection of the Environment edited by L. Pawlowski, A.J. Verdier and W.J. Lacy... 

The absorption of nitrogen oxides (NO, NO2, N2O4, N2O5, N2O, etc.) into water is employed to control air pollution by nitrogen oxides as well as to produce nitric acid. Of these oxides, NO, NO2 and N2O4 are much more important than the others. In the gas phase, the equilibrium constant Kp for the gas phase reaction... 

Detection of specific stable radicals in plants by EPR can be considered as a sensitive method of air pollution monitoring. The stable radicals are associated with products of free radical reactions initiated by various air pollutants, particularly nitrogen oxides. 

When a combustion engine converts fuel into energy, the reactions of the combustion process are incomplete. Incomplete combustion results in the production of poisonous carbon monoxide and undesirable nitrogen oxides. Since 1975, catalytic converters have reduced the exhaust emissions that contribute to air pollution by approximately 90%. 

In photochemical smog episodes, secondary air pollutants such as ozone, nitrogen dioxide, aldehydes, and peroxyacetyl nitrate are formed as a result of the chemical interaction of the primary air pollutants, principally nitric oxide and hydrocarbon vapors, with sunlight and air (Fig. 2.6) [49]. This interpretation of the processes involved has been verified by smog chamber experiments (Fig. 2.7), and has since been confirmed by field measurements as the sensitivity of ambient air instrumentation has improved [50, 51]. In photochemical smog episodes, it is the secondary pollutants that cause severe eye irritation and upper respiratory effects felt by people and at the same time causes serious damage to plants. 

Photochemical Smog Form of air pollution caused by nitrogen oxides and hydrocarbons in the air that react to form other pollutants because of catalysis by sunlight. 

To predict the stability of fluorinated polymers in the atmosphere polluted with nitrogen oxides, the ratio of rates of peroxynitrates in polytetrafluoroethylene (PTFE) by two mechanisms has been determined [19]. Chain peroxide radicals R 02 were obtained by photolysis of PTFE powder in a vacuum with the subsequent oxidation of fluoroalkyl macroradicals. The end peroxide radicals R 02 were generated by photolysis of the R 02 containing PTFE in the air. The exposure of PTFE samples containing chain or end peroxide macroradicals to NO2 results in decay of these radicals. The kinetics of the decay of peroxide radicals of both types is practically identical, and is likely to be determined by the rate of diffusion of NO into the... 

Nilrogi-n oxides are common by-products of fossil fuel combustion and are one of the most important types of air pollution. The nitric oxides react with UV radiation to form oxides of nitrogen, ozones and acids. The nitrogen oxides can have considerable impact ol Ibe lile ol polymers in the environment and can be responsible for failure of polymer pmdiKls, so il is important to know how these effects will be manifest. 

This reaction is the most important primary photochemical process involved in smog formation. The roles played by nitrogen oxides in smog formation and other forms of air pollution are discussed in Chapter 7. 

Pure ricin could be dispersed through the air, but ozone, nitrogen oxides and other pollutants would oxidise it within a few hours, rendering it harmless. Ricin is also inactivated by hypochlorite (bleach)... 

Air pollution can be considered to have three components sources, transport and transformations in the atmosphere, and receptors. The source emits airborne substances that, when released, are transported through the atmosphere. Some of the substances interact with sunlight or chemical species in the atmosphere and are transformed. Pollutants that are emitted directiy to the atmosphere are called primary pollutants pollutants that are formed in the atmosphere as a result of transformations are called secondary pollutants. The reactants that undergo transformation are referred to as precursors. An example of a secondary pollutant is O, and its precursors are NMHC and nitrogen oxides, NO, a combination of nitric oxide [10102-43-9] NO, and NO2. The receptor is the person, animal, plant, material, or ecosystem affected by the emissions. 

Air Pollution. Particulates and sulfur dioxide emissions from commercial oil shale operations would require proper control technology. Compliance monitoring carried out at the Unocal Parachute Creek Project for respirable particulates, oxides of nitrogen, and sulfur dioxide from 1986 to 1990 indicate a +99% reduction in sulfur emissions at the retort and shale oil upgrading faciUties. No violations for unauthorized air emissions were issued by the U.S. Environmental Protection Agency during this time (62). 

National Ambient Air Quality Standards. Under the Clean Air Act, six criterion pollutants, ie, pollutants of special concern, have been estabhshed by the EPA sulfur oxides (SO ), particulates, carbon monoxide (CO), nitrogen oxides (NO ), o2one (photochemical oxidants), and lead. National Ambient Air QuaUty Standards (NAAQS) were developed by EPA based on threshold levels of air pollution below which no adverse effects could be experienced on human health or the environment. 

Air pollution (qv) problems are characteri2ed by their scale and the types of pollutants involved. Pollutants are classified as being either primary, that is emitted direcdy, or secondary, ie, formed in the atmosphere through chemical or physical processes. Examples of primary pollutants are carbon monoxide [630-08-0] (qv), CO, lead [7439-92-1] (qv), Pb, chlorofluorocarbons, and many toxic compounds. Notable secondary pollutants include o2one [10028-15-6] (qv), O, which is formed in the troposphere by reactions of nitrogen oxides (NO ) and reactive organic gases (ROG), and sulfuric and nitric acids. 

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