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| DOI： |
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| Evaluatingthe Impact of Time after Starting Remediation of Coal-waste Piles Using Plants on Change of Heavy Metals in Soils |
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YU Yajun， WANG Jiping， PANG Bilin
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College of Geography Sciences, Shanxi Normal University, Linfen 041000, China
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| Abstract: |
| Soil contamination by heavy metals occurring inreclaiming coal-waste piles by planting cropsis a key environmental process and affected by many processes. To investigate the impact of the types of plants on soil contamination, four land uses - arable crops, vegetables, orchard and fallow - were tested in Cao Village of Shanxi Province to study the change in heavy metals three years, five years and seven years after the remediation started. The contents of five heavy metals: Hg, Cd, Pb, As and Ni were measured and their pollution levels were evaluated using the Nemerow index method. The results showed that the contents of the five heavy metals increased significantly with time after the remediation started. The contents of Pb and Ni increased in the top 0~40 cm soil; the single pollution index and the Nemerow index increased in the 20~40 cm soil. It was found that the contents of the five metals in the remediated soil is higher than those in the ordinary arable soil, especially in the 20~40 cm. Land usage affected heavy metal pollution and the contents of Hg and Pb were higher in the vegetable field than in the arable soils, while the content of Ni was lower in the vegetable and than in the arable land three years after remediation started. Seven years after the remediation, the contents of Pb and Ni,as well as their single pollution index and Nemerow index,in the fallow soil are higher than those in the orchard, suggesting that, compared with the fallow, vegetation can reduce heavy metal pollution. |
| Key words: coal waste pile; time after remediation started; land use types; soil pollution; heavy metals |
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