title: Mercury isotope signatures of seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.
abstract: Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ(202)Hg of particulate mercury (PHg) gradually decreased from -0.30‰ to -1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area.
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China; Guangxi Colleges and Universities Key Laboratory of Environmental Protection, School of Environment, Guangxi University, Nanning 530004, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
authors.forename: Jingji
authors.initials: J
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China. Electronic address: yuandx@xmu.edu.cn.
authors.forename: Dongxing
authors.initials: D
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
authors.forename: Bingyan
authors.initials: B
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
authors.forename: Kunning
authors.initials: K
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
authors.forename: Shuyuan
authors.initials: S
authors.lastname: Huang
mesh_terms: D002681:China; D003031:Coal; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation; D005740:Gases / Q000737:chemistry; D007220:Industrial Waste; D008629:Mercury Isotopes / Q000032:analysis*; D052638:Particulate Matter / Q000032:analysis*; D011210:Power Plants; D012623:Seawater / Q000032:analysis*; D013458:Sulfur Dioxide / Q000737:chemistry; D062065:Wastewater / Q000032:analysis; D014877:Water Pollution, Chemical / Q000517:prevention & control*
chemical_list: D003031:Coal; D005740:Gases; D007220:Industrial Waste; D008629:Mercury Isotopes; D052638:Particulate Matter; D013458:Sulfur Dioxide; D062065:Wastewater
keywords: Coal-fired power plant; Desulfurization seawater; Fractionation; Mercury isotope signatures; Tracing source