Combustion Processes as the Main Air Pollution Source

Where do trace gases originate For the most part, they come from anthropogenic activities related to the combustion of fossil fuels, leading to the production of the main primary pollutants CO, NQx, VOCs, and SO2. 

The (ideal) combustion of gasoline in internal combustion engines is expressed by the following equation  

If the ratio of hydrocarbons to oxygen is not adequate, partially oxidized compounds of carbon will be emitted, together with unreacted hydrocarbons. On the other hand, an excess of oxygen favors the production of NO because of the exothermicity of the reaction and because the oxygen required comes from the air  

Effects of Pollutants on the Chemistry of the Atmosphere, Hydrosphere, and Lithosphere 

The sulfur content of the fuels generates sulfur dioxide upon burning  

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