Capture gaseous arsenic in flue gas by amorphous iron manganese oxides with high SO2 resistance

In non-ferrous metal smelting, the problem of gaseous arsenic in high-sulfur flue gas is difficult to solve. Now we have developed oxygen-enriched amorphous iron manganese oxide (AFMBO) based on the unique superiority of iron-manganese oxide for arsenic capture to realize the effective control of gaseous arsenic in the non-ferrous smelting flue gas. The experimental results show that the arsenic adsorption capacity of AFMBO is up to 102.7 mg/g, which has surpassed most of the current adsorbents. In particular, AFMBO can effectively capture gaseous arsenic even at 12% v/v SO2 concentrations (88.45 mg/g). Moreover, the spent AFMBO possesses pronounced magnetic characteristics that make it easier to separate from dust, which is conducive to reducing the secondary environmental risk of arsenic. In terms of mechanism study, various characterization methods are used to explain the important role of lattice oxygen and adsorbed oxygen in the capture process of gaseous arsenic. Moreover, the reason for the efficient arsenic removal performance of AFMBO is also reasonably explained at the microscopic level. This study provides ideas and implications for gaseous arsenic pollution control research. •An amorphous iron manganese oxide (AFMBO) rich in surface adsorbed oxygen were developed.•The arsenic capture capacity of AFMBO was evaluated at different temperatures and different flue gas components.•AFMBO is effective in capturing gaseous arsenic even at 12% v/v SO2 concentrations.•Lattice oxygen and chemisorption oxygen synergistically promoted the capture of gaseous arsenic.