Typpioksidit

Typpioksidit, or nitrogen oxides (NOx), is a collective term for a group of inorganic chemical compounds that contain oxygen and nitrogen. The most common and significant forms are nitric oxide (NO) and nitrogen dioxide (NO2). Other less common oxides include nitrous oxide (N2O), dinitrogen trioxide (N2O3), dinitrogen tetroxide (N2O4), and dinitrogen pentoxide (N2O5).

NOx are primarily produced during high-temperature combustion processes, such as those found in internal combustion engines of vehicles, power plants, and industrial boilers. Natural sources include lightning strikes and volcanic activity. Nitrous oxide is also a significant byproduct of agricultural activities, particularly the use of fertilizers, and is a potent greenhouse gas.

In the atmosphere, NO is rapidly oxidized to NO2. Nitrogen dioxide is a reddish-brown gas that contributes to air pollution. It plays a crucial role in the formation of ground-level ozone, a major component of smog, through photochemical reactions. Ground-level ozone can cause respiratory problems, damage vegetation, and degrade materials. NOx also contributes to acid rain when they react with water, oxygen, and other chemicals in the atmosphere.

The environmental and health impacts of NOx emissions have led to regulations aimed at reducing their release. These regulations have spurred the development of technologies like catalytic converters in vehicles and low-NOx burners in industrial facilities to mitigate their formation and release.