Nitrogen oxide treatment refers to the control, recovery or utilization of nitrogen oxides (NOx) in waste gas or harmless treatment of NOx by improving combustion processes and equipment or by using catalytic reduction, absorption, adsorption and other methods of flue gas denitrification. NOx mainly includes nitric oxide (no) and nitrogen dioxide (NO2), which was recognized as one of the main pollutants in the atmosphere in the 1960s. The first way is to remove nitrogen from flue gas and the second is to control the generation of NOx