CO2 & SO2 are primary pollutant reach into the atmosphere from the sources then it react with other substances in the atmosphere to convert particulate matter through chemical bonding and reaction you see this attached file

Hence the transformation of NOx and SO2 to PM is mater of rather complex atmospheric chemistry, depending from the meteorological conditions, there is no such 'formulae'.

There is not specific formula for converting NO2 and SO2 into particulate matter. It depends on many environmental conditions like humidity, temperature, other primary pollutants present in atmosphere and their reactivity.

Regards,

Birendra Rajan

PhD - IIT Bombay

Dear Mohammad Rastegari thank you for your interesting and important technical question. Besides carbon monoxide (CO), carbon dioxide (CO2), ozone (O3), VOCs (= volatile organic compounds), unburned hydrocarbons, and diverse particulate matters, nitrogen oxides (mainly NO2) and sulfur oxides (mainly SO2) are among the most important air pollutants. There is no simple equation to convert both of them simultaneously into particulate matter. However, this is possible for the individual gases. SO2 can be converted into sulfate particulate matter, and NO2 can be converted into nitrate particulate matter. The problem is that both salts are considered air pollutants themselves. For more detailed information, please have a look at the following potentially useful article dealing with both dioxides:

Atmospheric conversion of sulfur dioxide to particulate sulfate and nitrogen dioxide to particulate nitrate and gaseous nitric acid in an urban area

Article Atmospheric conversion of sulfur dioxide to particulate sulf...

This article can be downloaded as free public full text from RG. Yet another very useful link is the following:

Particle formation from homogeneous reactions of sulphur dioxide and nitrogen dioxide

Article Particle formation from homogeneous reactions of sulphur dio...

Good luck with your research and please stay safe and healthy! 👍

Redox reactions of NO2 and SO2 may produce nitrate and sulphate ion particulates respectively. We can write the following equations:

2 NO2 + H2O -> HONO + NO3− + H+

SO2 + NO2 + 2H2O -> HONO + SO4-2 + 3H+