title: Rare earth elements in intertidal sediments of Bohai Bay, China: concentration, fractionation and the influence of sediment texture.
abstract: Surface sediments from intertidal Bohai Bay were assessed using a four-step sequential extraction procedure to determine their concentrations of rare earth elements (REEs) and the chemical forms in which those elements were present. The normalized ratios La/Gd and La/Yb showed that LREE contents were not significantly higher than the middle REEs or HREE contents. A negative Ce anomaly and positive Eu were observed in sand and silty sand sediments, whereas no significant Ce or Eu anomaly was found in clayey silt sediments. Residual fraction of REEs accounted for the majority of their total concentrations. Middle REEs were more easily leached than other REEs, especially in clayey silt sediment. REEs contents in the surface sediment from the intertidal Bohai Sea were consistent with data from the upper continental crust and China shallow sea sediments, indicating that they were generally unaffected by heavily anthropogenic effects from adjacent areas.
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong 264003, China; Department of Oceanography, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan. Electronic address: xlgao@yic.ac.cn.
authors.forename: Xuelu
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Oceanography, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
authors.forename: Chen-Tung
authors.initials: CT
authors.lastname: Arthur Chen
mesh_terms: D061006:Bays; 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
keywords: Chemical fractionation; Coastal zone; Intertidal environment; Rare earth elements; Sediment analysis; Sediment chemistry