Simultaneous removal of SO2, NO and Hg0 by wet scrubbing using urea+KMnO4 solution

article i nfo 0 Absorption A complex absorbent containing urea and KMnO4 was used to investigate simultaneous removal of SO2 ,N O and Hg 0 from flue gas. By focusing on NO, SO2 and Hg 0 removal efficiencies, the influences of different types of oxidants, urea concentration, KMnO4 concentration, Hg 0 inlet concentration, initial pH, reaction tempera- ture, SO2 and NO concentrations were systematically investigated. The results indicate that urea+KMnO4 so- lution cleaned up SO2 quite efficiently; the removal efficiency was more than 98%, and slightly affected by reaction conditions. NO and Hg 0 removal efficiencies depended primarily on the KMnO4 concentration. Urea concentration, reaction temperature, initial solution pH, SO2 and NO concentrations all had a strong in- fluence on the NO removal, but had a little influence on the Hg 0 removal. The inlet concentrations of Hg 0 con- tributed little to the removal of NO and Hg 0 . Meanwhile the optimal conditions were established, the absorption capacities of NO, SO2 and Hg 0 were calculated and the final reaction products in the solution were analyzed under the optimal conditions. This process is a promising method for the simultaneous remov- al of NO, SO2 and Hg 0 .