Simultaneous Removal of NO and SO2 from Flue Gas by UV/H2O2/CaO

The effects of several influencing factors (CaO and H2O2 concentration, gas flow, solution temperature, NO, SO2, O2 and CO2 concentration) on the simultaneous removal of NO and SO2 from flue gas by using a UV/H2O2/CaO process were studied. In addition, the anions in the liquid phase were measured by ion chromatography and the material balances for NO and SO2 were calculated. It was found that, under all experimental conditions, this process achieved a SO2 removal efficiency of 100?%. With the increase in CaO concentration, NO removal efficiency first increased and then remained almost unchanged. With the increase in H2O2 concentration, NO removal efficiency increased but the changes gradually became smaller. NO removal efficiency greatly decreased with increasing gas flow, NO concentration and CO2 concentration. Slightly increasing the solution temperature and SO2 concentration reduced NO removal efficiency. Increasing O2 concentration can promote the removal of NO. The anions in the liquid phase were mainly SO42 and NO3. Most of the low valence nitrogen elements in NO and the low valence sulfur elements in SO2 transformed into the high valence nitrogen element in NO3 and the high sulfur element in SO42.