Nitrogen Oxides NOx

Nitrogen oxides and their products occur as the result of the natural influences or human activities. Natural sources of NOx are lightning, as well as biological and non-biological processes in the soil. Biggest anthropogenic sources of NO2 are the combustion processes at high temperatures (as the ones occurring in automobiles), coal, oil and diesel combustion, home fireboxes and waste incineration.

NO is a colorless gas under standard conditions and forms with a reaction between N2 and O2 at a high temperature. Main source of NO are the exhaust vapors from the automobile engines. NO2 is brown-red, it forms during incineration processes in polluted air in the main urban centers, and is highly reactive gas formed by oxidizing nitrogen monoxide (NO). High concentrations of this pollutant have sharp scent, while low concentrations have a scent similar to hydrogen.

High levels of nitrous oxides can have a negative effect on the vegetation, such as damage and hindered growth. So called “acid rain” forms as a reaction with other substances in the atmosphere causing dispersion of fog, snow and particulate matter, and have a harmful effect on the environment.

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