fig4

Figure 4. Co-benefit heavy-metal removal along a representative flue-gas treatment train. Gaseous metals released from the incinerator undergo condensation and particle association during cooling, while SCR promotes Hg⁰ oxidation. Optional ACI enhances adsorption before ESPs or BFs collect fly ash, condensed metal species, and spent sorbents. WFGD captures soluble Hg(II) species and remaining particles, transferring metals into gypsum- and wastewater-associated streams before the treated gas reaches the stack. The solid and liquid outputs require further management. The diagram summarizes representative control functions; the equipment sequence varies with the industrial process and plant design. ACI: Activated-carbon injection; SCR: selective catalytic reduction; ESP: electrostatic precipitator; BF: fabric filter; WFGD: wet flue-gas desulfurization; HM: heavy metal.