title: A novel pre-oxidation method for elemental mercury removal utilizing a complex vaporized absorbent.
abstract: A novel semi-dry integrative method for elemental mercury (Hg(0)) removal has been proposed in this paper, in which Hg(0) was initially pre-oxidized by a vaporized liquid-phase complex absorbent (LCA) composed of a Fenton reagent, peracetic acid (CH3COOOH) and sodium chloride (NaCl), after which Hg(2+) was absorbed by the resultant Ca(OH)2. The experimental results indicated that CH3COOOH and NaCl were the best additives for Hg(0) oxidation. Among the influencing factors, the pH of the LCA and the adding rate of the LCA significantly affected the Hg(0) removal. The coexisting gases, SO2 and NO, were characterized as either increasing or inhibiting in the removal process, depending on their concentrations. Under optimal reaction conditions, the efficiency for the single removal of Hg(0) was 91%. Under identical conditions, the efficiencies of the simultaneous removal of SO2, NO and Hg(0) were 100%, 79.5% and 80.4%, respectively. Finally, the reaction mechanism for the simultaneous removal of SO2, NO and Hg(0) was proposed based on the characteristics of the removal products as determined by X-ray diffraction (XRD), atomic fluorescence spectrometry (AFS), the analysis of the electrode potentials, and through data from related research references.
authors.affiliation: School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, P.R. China. Electronic address: zhaoyi9515@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, P.R. China.
authors.forename: Runlong
authors.initials: R
authors.lastname: Hao
authors.affiliation: School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, P.R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Guo
mesh_terms: D000327:Adsorption; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008628:Mercury / Q000302:isolation & purification*; D017942:Nitric Acid / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010463:Peracetic Acid / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000302:isolation & purification
chemical_list: C045076:Fenton's reagent; D013458:Sulfur Dioxide; D017942:Nitric Acid; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D007501:Iron; D008628:Mercury; D010463:Peracetic Acid
keywords: Hg(0) removal; Pre-oxidation; Reaction mechanism of simultaneous removal of SO(2), NO and Hg(0); Simultaneous removal of SO(2), NO and Hg(0); Vaporized liquid-phase complex absorbent