Elemental Mercury Removal from Flue Gas by Diperiodatoargentate(III) Solution

Abstract

Abstract A series of experiments were conducted in a bubble column reactor to investigate the effects of key influencing factors such as the diperiodatoargentate (III) concentration, the reaction temperature, the solution pH, O2 concentration, SO2 concentration and NO concentration on the Hg0 removal. The results indicated that the average removal efficiency of 77.5 % was reached under the optimal conditions in which the DPA concentration was 1.03mmol/L, the reaction temperature was 40 °C and the solution pH was 8.5; SO2 inhibited Hg0 oxidation due to its competition for the limited oxidant; when NO was in a low concentration, it was found to be a promotion for Hg0 oxidation. The spent solution was analyzed by the CVAFS, The results illustrated that Hg0 was oxidized into Hg2+ by DPA then DPA was converted into Ag+, from which, the reaction mechanism was speculated accordingly.