An oxidation absorption technology of Hg-0 in the gas phase using double metal catalyzers-double oxidants coactivation was developed. Several experiments were performed to study the main influencing factors, key reactive species, oxidation products, and mechanism of Hg-0 oxidation absorption. It was found that higher concentration of Fe2+ and Cu2+ led to an increase in Hg-0 removal efficiency. The removal efficiency of Hg-0 was declined through increasing the reagent pH value, flue gas flow rate, Hg-0 inlet concentration, and inlet content of NO/SO2. Changing the removal temperature and concentrations of PMS (peroxymonosulfate) and H2O2 resulted in a dual influence on Hg-0 oxidation absorption. Under the optimized experimental conditions, the maximum removal efficiency of Hg-0 is up to 97.5%. Due to the significant synergistic activation effect, bigger reactive species yield and higher Hg-0 removal efficiency were obtained in the double metal catalyzers-double oxidants coactivation system than those in the other contrasted systems, which were caused by the redox cycling by double metal catalyzers and the free radical capture intermediate formed between double oxidants. The Hg-0 oxidation absorption was mainly achieved by the oxidation of (OH)-O-center dot and SO4-center dot, and Hg2+ was confirmed to be the main products of Hg-0 oxidation absorption in the developed coactivation system.
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