title: Tracing mercury contamination sources in sediments using mercury isotope compositions.
abstract: Mercury (Hg) isotope ratios were determined in two sediment cores collected from two adjacent reservoirs in Guizhou, China, including Hongfeng Reservoir and Baihua Reservoir. Hg isotope compositions were also analyzed in a soil sample collected from the catchment of Hongfeng Reservoir and three cinnabar samples collected from the Wanshan Hg mine. Baihua Reservoir was contaminated with runoff from Guizhou Organic Chemical Plant (GOCP) when metallic Hg was used as a catalyst to produce acetic acid. Hongfeng Reservoir, located upstream of Baihua, receives Hg from runoff and atmospheric deposition. We demonstrated that delta(202)Hg values relative to NIST 3133 of sediment in Baihua Reservoir ranging from -0.60 to -1.10 per thousand were distinctively different from those in Hongfeng Reservoir varying from -1.67 to -2.02 per thousand. While sediments from both Baihua and Hongfeng Reservoirs were characterized by mass dependent variation (MDF), only Hongfeng Reservoir sediments were characterized by mass independent variation (MIF). Moreover, by using a binary mixing model, we demonstrated the major source of Hg in sediment of Hongfeng Reservoir was from runoff due to soil erosion, which was consistent with the conclusion obtained from a previous Hg balance study. This study demonstrates Hg isotope data are valuable tracers for determining Hg contamination sources in sediments.
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China. fengxinbin@vip.skleg.cn
authors.forename: Xinbin
authors.initials: X
authors.lastname: Feng
authors.forename: Delphine
authors.initials: D
authors.lastname: Foucher
authors.forename: Holger
authors.initials: H
authors.lastname: Hintelmann
authors.forename: Haiyu
authors.initials: H
authors.lastname: Yan
authors.forename: Tianrong
authors.initials: T
authors.lastname: He
authors.forename: Guangle
authors.initials: G
authors.lastname: Qiu
mesh_terms: D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000032:analysis*; D007554:Isotopes / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D008629:Mercury Isotopes / Q000032:analysis*; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply
chemical_list: D007554:Isotopes; D008629:Mercury Isotopes; D008670:Metals; D014874:Water Pollutants, Chemical; D008628:Mercury