Removal of Elemental Mercury from Flue Gas Using Cobalt-Containing Biomaterial Carbon Prepared from Contaminated Iris sibirica Biomass

[Image: see text] Iris sibirica biomass (ISBM) used for cobalt (Co) pollution remediation was prepared by one-step pyrolysis and employed to remove elemental mercury (Hg(0)) from flue gas. Results showed that the ISBM pyrolyzed at 700 °C (ISBM700) exhibited good Hg(0) removal performance (about 86%) at 150 °C. The existence of NO and O(2) facilitated the removal of Hg(0), while SO(2) and water vapor inhibited it. Characterization analysis (including N(2) adsorption–desorption, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry) showed that ISBM700 has a relatively higher specific surface area, a quantity of lattice oxygen derived from well-dispersed amorphous-phase CoO(x), and abundant oxygen functional groups. A Mars–Maessen mechanism is thought to be involved in the Hg(0) removal process. The adsorbed Hg(0) could be oxidized to HgO by the surface oxygen species derived from CoO(x), and then, the consumed surface oxygen species can be replenished by O(2). Therefore, the Co-contaminated I. sibirica biomass (CCIB) from phytoremediation could be utilized for Hg(0) removal after being pyrolyzed instead of any chemical modification.