Effective removal of nitrogen oxides (NOx) from flue gas allows more fossil fuels to be produced and utilized with less negative impact on the environment. It would be more cost-effective, however, if nitric oxide (NO) is oxidized to soluble nitrate and nitrite and then removed from the air by existing desulfurization wet scrubbers. This paper compares the effectiveness of three different oxidants for this purpose, namely, ethylenediaminetetraacetic acid; iron (2+) (Fe(II)-EDTA), hexamninecobalt(II) chloride ([Co(NH3)(6)]Cl-2), and hydrogen peroxide (H2O2). Experimental results using column reactors showed that [Co(NH3)(6)]Cl-2 was more effective over the same period of time. The best initial NO removal efficiency of about 96.45% was measured at the inlet flow rate of 500 ml/min; the temperature of approximately 19 degrees C; the pH value of around 10.5; and the concentrations of [Co(NH3)(6)]Cl-2, NO and O-2 of 0.06 mol/L, 500 ppm and 5.0%, respectively. (C) 2011 Elsevier Ltd. All rights reserved.