title: Characteristics of dissolved organic matter (DOM) and relationship with dissolved mercury in Xiaoqing River-Laizhou Bay estuary, Bohai Sea, China.
abstract: Because of heterogeneous properties, dissolved organic matter (DOM) is known to control the environmental fate of a variety of organic pollutants and trace metals in aquatic systems. Here we report absorptive and fluorescence properties of DOM, in concurrence with concentrations of dissolved mercury (Hg), along the Xiaoqing River-Laizhou Bay estuary system located in the Bohai Sea of China. A mixing model consisting of the two end-members terrestrial and aquatic DOM demonstrated that terrestrial signatures decreased significantly from the river into the estuary. Quasi-conservative mixing behavior of DOM sources suggests that the variations in the average DOM composition were governed by physical processes (e.g., dilution) rather than by new production and/or degradation processes. In contrast to some previous studies of river-estuary systems, the Xiaoqing River-Laizhou Bay estuary system displayed a non-significant correlation between DOM and Hg quantities. Based on this and the variation of Hg concentration along the salinity gradient, we concluded that Hg showed a non-conservative mixing behavior of suggested end-member sources. Thus, rather than mixing, Hg concentration variations seemed to be controlled by biogeochemical processes.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Department of Environment Science and Engineering, Southwest University, Chongqing 400716, China; Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90183, Sweden.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-90183, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Skyllberg
authors.affiliation: Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Björn
authors.affiliation: School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States.
authors.forename: Nelson W
authors.initials: NW
authors.lastname: Green
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences (CAS), Yantai 264003, China. Electronic address: jhtang@yic.ac.cn.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Tang
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Department of Environment Science and Engineering, Southwest University, Chongqing 400716, China. Electronic address: dywang@swu.edu.cn.
authors.forename: Dingyong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Department of Environment Science and Engineering, Southwest University, Chongqing 400716, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Agricultural Resources and Environment, College of Resources and Environment, Department of Environment Science and Engineering, Southwest University, Chongqing 400716, China.
authors.forename: Chuxian
authors.initials: C
authors.lastname: Li
mesh_terms: D002681:China; D063366:Estuaries; D008628:Mercury / Q000032:analysis*; D009930:Organic Chemicals / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D054712:Salinity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Bohai Sea; Dissolved organic matter; Fluorescence; Laizhou Bay; Mercury; UV–Vis absorption