Hsu C.-JChen Y.-HHsi H.-C.HSING-CHENG HSI2021-08-052021-08-052020489697https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076605793&doi=10.1016%2fj.scitotenv.2019.135172&partnerID=40&md5=01dcacf1b1cc8b849ff8e16b62a23cc9https://scholars.lib.ntu.edu.tw/handle/123456789/577004The potential impacts of seawater flue gas desulfurization (SFGD) process used in coal-fired power plants have been greatly concerned because the wastewater containing Hg is directly discharged into the ocean environment without proper treatment. Furthermore, the re-emission of Hg as Hg0 to the atmosphere from SFGD wastewater caused by the reduction of aqueous Hg2+ has also been observed. This study investigated the dependence of Hg2+ adsorption behavior for sulfurized activated carbon (SAC) in actual SFGD wastewater on various influencing factors, including initial Hg2+ concentration, solution pH, contact time, temperature, and the addition of oxidant (sodium hypochlorite, NaClO). SAC exhibited greater Hg2+ adsorption than raw activated carbon at an initial Hg2+ concentration of more than 4,723 ng L?1. The Hg2+ removal efficiency of SAC was slightly larger at pH 7.0 and 8.0 than that at pH within 2.0–6.0. Hg2+ adsorption on SAC was well correlated with the linear adsorption model. Kinetic analysis results indicate that pseudo-second-order adsorption may serve as the rate-limiting reaction of Hg2+ adsorption on SAC. Thermodynamic analyses confirmed the endothermic and spontaneous adsorption behavior of Hg2+ on SAC in the seawater environment. Notably, the addition of NaClO significantly reduced the Hg2+ removal efficiency when SAC was used as the adsorbent. Nevertheless, NaClO addition also inhibited the reduction reaction of Hg2+ to Hg0 by forming strong Hg[sbnd]Cl complexes, which decreased the risk of Hg0 reemitted into the atmosphere via a SFGD system. ? 2019 Elsevier B.V.Activated carbon; Activated carbon treatment; Adsorption; Chlorine compounds; Coal; Coal fueled furnaces; Desulfurization; Efficiency; Flue gases; Flues; Fossil fuel power plants; Gas plants; Mercury (metal); Seawater; Sodium compounds; Thermoanalysis; Wastewater treatment; Coal-fired power plant; Flue gas desulfurization; Rate-limiting reaction; Re-emission; Removal efficiencies; Sodium hypochlorites; Spontaneous adsorption; Thermo dynamic analysis; Mercury compounds; activated carbon; hypochlorite sodium; mercury; sea water; sulfurized activated carbon; unclassified drug; activated carbon; adsorption; coal-fired power plant; concentration (composition); emission; inhibitor; mercury (element); oxidant; pH; sodium chloride; temperature effect; wastewater; adsorption; air pollution control; aqueous solution; Article; atmosphere; chemical reaction; contact time; controlled study; desulfurization; heavy metal removal; kinetics; pH; priority journal; rate limiting reaction; reemission; seawater flue gas desulfurization; temperature; thermodynamics[SDGs]SDG6[SDGs]SDG14journal article10.1016/j.scitotenv.2019.135172318312442-s2.0-85076605793