|
| Heavy Metal Pollution in Soils Surrounding an Iron Tailings in Upstream Areas of Hanjiang River, Shaanxi Province |
| Received:March 26, 2015 |
| View Full Text View/Add Comment Download reader |
| KeyWord:soils;iron tailings;heavy metals;fractions;geo-accumulation index;ecological risk index |
| Author Name | Affiliation | E-mail | | SONG Feng-min | College of Resources and Environment, Northwest A&F University, Yangling 712100, China
School of Chemistry and Environmental Science, Shaanxi University of Technology, Hanzhong 723001, China | | | ZHANG Xing-chang | Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China
Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China | zhangxc@ms.iswc.ac.cn | | WANG Yan-min | School of Chemistry and Environmental Science, Shaanxi University of Technology, Hanzhong 723001, China | | | LI Chen | School of Chemistry and Environmental Science, Shaanxi University of Technology, Hanzhong 723001, China | | | TANG Bo | School of Chemistry and Environmental Science, Shaanxi University of Technology, Hanzhong 723001, China | |
|
| Hits: 3117 |
| Download times: 3145 |
| Abstract: |
| The distribution characteristics and potential ecological risk of heavy metals in soils surrounding an iron tailings in the upstream areas of Hanjiang River, Shaanxi Province were investigated. The geoaccumulation index and the ecological risk index were calculated to assess the heavy metal pollution levels. The concentrations of metals in the soils were higher than their background values, except Ti. Chemical fractionation showed that Fe, Hg and As were mostly associated with residual fraction(over 80%), whereas the residual fraction for the other metals was only about 50%. However, the other fractions for Cd, Mn, Ni, and Zn were relatively high. Mn was averagely 24.07% in exchangeable and 17.2% in reducible fractions, Zn 22.07% associated with reducible fraction and 16.1% with oxidizable fraction, Ni 28.9% with oxidizable fraction and 21.8% with reducible fraction, and Cd 22.8% with oxidizable fraction and 18.5% with reducible fraction. Co was 25.5%, 18.6%, and 18.4% in oxidizable, exchangeable, and reducible fractions, respectively. The geo-accumulation index indicated that these soils were at moderate to severe pollution by Hg and Cd, moderate pollution by As and Co, and no to moderate pollution by Fe, Mn, Ni, and Zn. The ecological risk index showed that Cd and Hg had the highest ecological risk and As was at moderate ecological risk, while other elements had slight ecological risk. In summary, the studied area showed higher ecological risk of heavy metals. Appropriate measures should be taken to protect the soils from heavy metal pollution, particularly Cd, Hg, and As. |
|
|
|
