SO2 and NO emitted from coal-fired power plants have caused serious air pollution in China.In this study,a test system for NO oxidation using O3 is established.The basic characteristics of NO oxidation and products forms are studied.A separate test system for the combined removal of SO2 and NOx is also established,and the absorption characteristics of NOx are studied.The characteristics of NO oxidation and NOx absorption were verified in a 35 t·h-1 industrial boiler wet combined desulfurization and denitrification project.The operating economy of ozone oxidation wet denitrification technology is analyzed.The results show that O3 has a high rate and strong selectivity for NO oxidation.When O3 is insufficient,the primary oxidation product is NO2.When O3 is present in excess,NO2 continues to get oxidized to N2O5 or NO3.The removal efficiency of NO2 in alkaline absorption system is low (only about 15％).NOx removal efficiency can be improved by oxidizing NOx to N2O5 or NO3 by increasing ozone ratio.When the molar ratio of O3/NO is 1.77,the NOx removal efficiency reaches 90.3％,while the operating cost of removing NOx per kilogram is 6.06 USD (NO2).