title: Fraction characteristics of rare earth elements in the surface sediment of Bohai Bay, North China.
abstract: Surface sediment samples were collected at 27 stations of Bohai Bay, North China. Sequential extractions were carried out in this study. REE were leached out from four labile fractions: Exchangeable (L1), bound to carbonates (L2), bound to Fe-Mn oxides (L3), bound to organic matter (L4), and the remainder was residual (R5). The total contents of REE fluctuate slightly in Bohai Bay, and are mainly concentrated in the middle region, showing relatively higher levels in the north than that in the south of Bohai Bay. Percentages of L1, L2, L3, L4, and R5 for REE suggest that the residual fraction accounts for the major component of REE, whereas Fe-Mn oxides also play important roles in combining labile REE. As the REE complex is not stabilized, the competition of complex could induce dissociation of the complex and redistribution of the REE in various environments. According to REE patterns and Y/Ho ratios of samples, REE are not anthropogenic or oceanic sources but riverine input, whereas suitable environment varieties can slightly affect the patterns and fractionations of REE. As powerful tracers for the variable of environment, higher anomaly of Eu and Ce in southern regions indicates a greater reduction in the condition of surface sediment in the south than that in the north of Bohai Bay.
authors.affiliation: Key laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China.
authors.forename: Yayan
authors.initials: Y
authors.lastname: Xu
authors.forename: Jinming
authors.initials: J
authors.lastname: Song
authors.forename: Liqin
authors.initials: L
authors.lastname: Duan
authors.forename: Xuegang
authors.initials: X
authors.lastname: Li
authors.forename: Huamao
authors.initials: H
authors.lastname: Yuan
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Sisi
authors.initials: S
authors.lastname: Xu
authors.forename: Mo
authors.initials: M
authors.lastname: Zhang
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Wu
authors.forename: Xuebo
authors.initials: X
authors.lastname: Yin
mesh_terms: D061006:Bays / Q000737:chemistry; D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D008674:Metals, Rare Earth / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008674:Metals, Rare Earth; D014874:Water Pollutants, Chemical