Dominants and accumulation of rare earth elements in sediments derived from riparian and depressional marshes
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The rare earth elements (REEs) in the sediments of the Xianghai wetlands were measured by inductively coupled plasma spectrometry. The REEs accumulation rates in two sedimentation cores derived from the riparian and depressional marshes were determined by 210Pb method. The results showed that REEs concentrations in the Xianghai wetland sediments (∑REEs, 116 mg kg−1) were lower than the corresponding values in Chinese soils (181 mg kg−1) and river sediments (∑REEs, 158–191 mg kg−1). Under alkaline conditions (with pH, 8.2–10.3), the light REEs were more enriched than the heavy REEs. Cerium is the predominant element, and accounts for 30–33% of the total REEs. REEs in the depressional marsh sediments were relatively high (∑REEs, 127 vs. 104 mg kg−1), especially light REEs contents. A significantly positive correlation was found between the neighboring elements except Pr and Dy. The different types of vertical distribution of REEs between the riparian and the depressional marsh can partly result from long-term differing hydrological regimes. Generally, depressional marsh had accumulated much more REEs than riparian marsh (the mean accumulation rates of ∑REEs, 102.98 vs. 48.89 μg cm−2 year−1).
KeywordsRare earth elements Vertical distribution Accumulation rates Sediments Wetlands
The authors gratefully acknowledge Yu-xia Zhang and Chao-ying Wang for valuable help with the sampling; Hai-yang Zhao and Bo-kun Lou for sample analyses; and the National Natural Science Foundation of China (No. 40871089) and the State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS (No. SKLLQG0910) for financial support.
- Efremova TT, Efremov SP, Koutzenogii KP, Smirnova AI, Peresedov VF, Ostrovnaya TM, Chinaeva VP (1999) Biogeochemical migration of Al, Hf, Sc, Th and rare-earth metals in the profile of the deep-seated eutrophic marsh in the interfluve of the Ob and Tom rivers. J Radioanal Nucl Chem 240:329–334CrossRefGoogle Scholar
- Keddy PA (2000) Wetland ecology principles and conservation. Cambridge University Press, CambridgeGoogle Scholar
- McLennan SM (1989) Rare earth elements in sedimentary rocks; influence of provenance and sedimentary processes. Rev Mineral Geochem 21:169–200Google Scholar
- Mitsch WJ, Gosselink JG (2000) Wetlands, 3rd edn. Wiley and Sons, New YorkGoogle Scholar
- Wang Y, Wei F (1995) Element chemistry of soil environment. Environmental Science Press, Beijing (in Chinese)Google Scholar
- Xu ZF, Han GL, Tang Y (2007) Geochemistry of dissolved rare earth elements in the Xijiang River, China. Geochim Cosmochim Acta 71(15):A1134Google Scholar
- Yang Sh, Li C (1999) REE geochemistry and tracing application in the Yangtze River and the Yellow River sediments. Geochemistry 28(4):374–380 (in Chinese with English abstract)Google Scholar
- Zhang Y, Shao Ch, Zhang X, Wang X (2003) Pretreatment for determination of REEs in soils by ICP-AES. J Agro-Environ Sci 22(6):707–710 (in Chinese with English abstract)Google Scholar
- Zhu JG, Zhang YL, Sun J, Yamasaki S, Tsumura A (1997a) Water-soluble rare earth elements in some soils of China. Pedosphere 7(1):25–30Google Scholar