Gaseous Elemental Mercury Removal Using Combined Metal Ions and Heat Activated Peroxymonosulfate/H 2 O 2 Solutions

Several novel oxidation removal processes of elemental mercury (Hg 0 ) from flue gas using combined Fe 2+ /Mn 2+ and heat activated peroxymonosulfate (PMS)/H 2 O 2 solutions in a bubbling reactor were proposed. The operating parameters (e.g., PMS/H 2 O 2 concentration, Fe 2+ /Mn 2+ concentration, solution pH, activation temperature, and Hg 0 /NO/SO 2 /O 2 /CO 2 concentration), mechanism and mass transfer‐reaction kinetics of Hg 0 removal were investigated. The results show that heat and Fe 2+ /Mn 2+ have significant synergistic effect for activating PMS and PMS/H 2 O 2 to produce free radicals to oxidize Hg 0 . Hg 0 removal is strongly affected by PMS/H 2 O 2 concentration, Fe 2+ /Mn 2+ concentration, activation temperature, and solution pH. S O 4 − · and ·OH produced from combined heat and Fe 2+ /Mn 2+ activated PMS/H 2 O 2 play a leading role in Hg 0 removal. Under optimized experimental conditions, Hg 0 removal efficiencies reach 100, 94.9, 66.9, and 58.9% in heat/Fe 2+ /PMS/H 2 O 2 , heat/Mn 2+ /PMS/H 2 O 2 , heat/Fe 2+ /PMS, and heat/Mn 2+ /PMS systems, respectively. Hg 0 removal processes in four systems belong to fast reaction and were controlled by mass transfer under optimized experimental conditions. © 2018 American Institute of Chemical Engineers AIChE J , 65: 161–174, 2019