Geochemical speciation and risk assessment of metals in the river sediments from Dan River Drainage, China

ABSTRACT

This study investigates the partitioning of metals in surface sediments from the Dan River drainage basin, the source of drinking water for the South to North Water Transfer Project, China, to determine their bioavailability and associated levels of risk. Sediment samples were collected from 99 sites along the Dan River, and the concentration of each element fraction was determined using sequential extraction and inductively coupled plasma-mass spectrometry. The residual fraction was the major phase for most metals sampled. Among the non-residual fractions, greater proportions of Zn, Mn and Cd were transported in in the available phase, whereas Ba, Sb, Pb and As were mainly found in the reducible phase. The oxidisable phase was important for the transport of Ni, Co, Cr and Cu in sediments. This analysis of sediments from the Dan River basin indicates a very high risk of pollution from Cd, Co, Mn, Sb and Zn. Combined with the sediments with extremely high concentrations, the Dan, Laoguan and Yinhua rivers, which have been affected by ore-mining activities, pose a very high risk to the surrounding areas and should be the subject of future studies.

KEYWORDS:

• Dan River drainage
• surface sediment
• heavy metal
• BCR sequential extraction
• risk assessment code (RAC)

Acknowledgements

Thanks to Tianming Xia, Yingqun Ma and Zhichao Liu (Chinese Research Academy of Environmental Sciences) for the laboratory work, to Junliang Sun and Shengdong Cheng (Peking University, China) for kind discussions, and to Hildred Crill (Stockholm University, Sweden) for improving the English.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors gratefully acknowledge financial support from National Natural Science Foundation of China (grant to T.R. Wu, No. 41372225) and China Scholarship Council (grant to Qingpeng Meng, file no. 201406010057).