Pedosphere 23(2): 265--272, 2013
ISSN 1002-0160/CN 32-1315/P
©2013 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Adsorption and desorption of mercury(II) in three forest soils in Shandong Province, China |
XUE Tong1, WANG Ren-Qing1,2,3, ZHANG Meng-Meng1 and DAI Jiu-Lan1 |
1 Environment Research Institute, Shandong University, Jinan 250100 (China)
2Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Jinan 250100 (China)
3Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan 250100 (China) |
| ABSTRACT |
| As one of the most toxic heavy metals with persistence, bioaccumulation, and toxicity in environment, mercury and its environmental problems have caused a global concern. To fully understand the behavior and fate of mercury (Hg)(II) in forest soils, a series of batch experiments were conducted to determine the adsorption and desorption characteristics of Hg(II) by three dark brown forest soils from Mount Taishan, Laoshan Mountain, and Fanggan Village in Shandong Province, China. The adsorption solution was prepared using 0.1 mol L-1 NaNO3 as background electrolyte, with Hg(II) at rising concentration gradients of 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mg L-1. Fourier transform infrared (FTIR) spectroscopy was adopted to characterize the soil samples and soil-Hg complexes. It was found that Hg(II) adsorption isotherms could be well fitted with both Langmuir and Freundlich equations. The soil from Mount Tai had the largest potential Hg(II) adsorption capacity, though with less adsorptive intensity. The percentages of Hg(II) desorbed from all soil samples were less than 0.6%, which suggested that all the soils studied had a high binding strength for Hg(II). The soil from Mount Taishan had a higher Hg(II) desorption capacity than the other soils, which indicated that the Hg(II) deposited on the topsoil of Mount Taishan from atmosphere may easily discharge to surface water through runoff. Results of the FTIR spectroscopy showed that the three soils contained the same functional groups. The relative absorbencies of soil-Hg complexes changed significantly compared with those of the soil samples and the adsorption of Hg(II) mainly acted on the O--H, C--O, and C=O groups of the soils. |
| Key Words: atmosphere deposition, binding strength, functional groups, FTIR spectroscopy, soil-Hg complex |
| Citation: Xue, T., Wang, R. Q., Zhang, M. M. and Dai, J. L. 2013. Adsorption and desorption of mercury(II) in three forest soils in Shandong Province, China. Pedosphere. 23(2): 265-272. |
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