Desulfurization and denitrification refer to the removal of SO2 (sulfur dioxide) and NOx (nitrogen oxides) from flue gas, as these gases can form acid rain when released into the atmosphere, posing significant harm to humans. The process of desulfurization and denitrification involves reducing NOx to N2, thereby eliminating NOx from the flue gas. It can be categorized into wet denitrification and dry denitrification based on the treatment process. It mainly includes methods such as acid absorption, alkali absorption, selective catalytic reduction, non-selective catalytic reduction, adsorption, and plasma activation.