Seaweed bio-chars modified with metal chloride for elemental mercury capture from simulated flue gas

Metal chloride-impregnated seaweed bio-chars, derived from waste algae (Enteromorpha), are served as solid sorbents for Hg-0 capture from simulated flue gas. The impacts of various metal chloride modification on Hg-0 removal performance, i.e. FeCl3 , CuCl2 , ZnCl2 , CoCl2 , and CeCl3 , are studied. The results display that the Hg-0 removal performances of Enteromorpha derived bio-chars are greatly enhanced by immersing metal chlorides. FeCl3-and CeCl3 -modified bio-chars exhibits the optimal Hg-0 removal performance. Oxygen and NO show a promotional effect on Hg-0 removal, whereas H2O suppresses Hg-0 adsorption. Lower concentration of SO2 favors Hg-0 removal, but higher concentration of SO2 inhibits Hg-0 adsorption. Hg-0 is oxidized by covalent chloride groups and metal oxides on the metal chloride-impregnated bio-chars.