The ammonia/urea solution wet desulfurization and denitrification technology has low denitration efficiency in industrial application. In this study

the performance of simultaneous removal of SO

2

and NO

x

by the aqueous urea/ammonium ion/additive solution in a bubbling reactor was investigated

and the ions concentration and pH values of the solution after absorption was analyzed. The results show that the oxidation of NO by O

2

in the gas phase is the dominant mechanism of NO

x

removal by the aqueous urea/ammonium ion solution. The additive has no catalytic effect on NO absorption without the presence of O

2

and the presence of SO

2

promotes the NO absorption. The experiment

al results indicate that the reaction mechanism and the effect concerning NO removal by various additives are different. The alkanolamines additive has buffer and catalytic effects

and the mixing alkanolamines additive works better. However

the SO

2

absorption is in competition with the NO removal in the aqueous urea solution with KMnO

4

. Under the experimental condition

the NO removal efficiency is lowest in the ammonia/water solution

and highest in the urea solution. The urea could prevent the nitrous acid from decomposing into NO

and the pH of the absorption solution decreases obviously while adding ammonium bicarbonate

which is unfavourable to NO

x

removal.