摘要
通过调查和采样,测定了安庆菜子湖退耕湿地土壤重金属含量;采用潜在生态危险指数法,评价了湿地土壤重金属含量的生态危险;对土壤重金属和土壤理化性质进行主成分分析和Pearson相关性分析。结果表明,研究区土壤重金属含量都低于国家土壤质量二级标准,表明研究区的土壤重金属污染程度较低。除Pb之外,土壤其他重金属含量都大于长江流域土壤背景值,表明研究区土壤重金属存在一定的累积。随土壤深度增加,不同重金属含量变化存在差异,Mn含量在增加,并在底层富集明显,Zn、Pb、Cr和Cu含量波动变化,Ni含量在减少。研究区土壤重金属风险等级整体偏低,属轻度污染。酸模(Rumex acetosa)群落下的土壤中的重金属含量最高,其潜在生态危害程度也最高,其次为芦苇(Phragmites australis)群落下的土壤,细叶薹草(Carex rigescens)群落下的土壤的潜在生态危害程度最低。土壤中Cu、Pb、Ni和Zn含量受人类活动影响较大,农业活动是其主要来源,Cr可能来自自然源,Mn和Ni的来源较复杂。
In order to know soil environment status, the accumulation and distributions of heavy metal in soils of Caizi lake wetland in Anqing were researched. The potential ecological risk index method was applied to assess the potential ecological risk in this area. Correlation between heavy metals and soil physicochemical properties was identified using correlation analysis and principal component analysis. The results showed that the contents of heavy metal were lower in soils of Caizi lake than the second grade standard values of Chinese environmental quality standards for soils, indicated that heavy metals were slight pollution in wetland soil. But the contents of heavy metals were higher than the grade standard values of Changjiang standard for soils, indicated that heavy metal accumulated in wetland soil. The contents of different heavy metals changed significantly along the soil profile, the content of manganese gradually increased with increasing depth in the soil and enriched in the underlying soil, the contents of zinc, lead and chromium changed with the increase of soil depth, the content of copper was decreased and then increased with the increase of soil depth, the content of nickel reduced with the increase of soil depth. Potential ecological risk index showed that heavy metals were slight pollution, the risk level of heavy metals in Phragmites australis wetland soil and Rumex acetosa wetland soil were more serious than that of Carex rigescens wetland soil. Correlation analysis showed that the contents of copper, lead and zinc significantly correlated with one another, indicating that they might come from similar sources. Copper, lead and zinc probably came from the agricultural production activities. Chromium mainly came from soil parent material, nickel and manganese probably came from complicated sources. Correlation analysis showed the contents of nickel, lead and copper significantly correlated with organic matter and the physical clay content of soil. Manganese concentration was positive correlated with p H.
出处
《湿地科学》
CSCD
北大核心
2015年第4期437-443,共7页
Wetland Science
基金
国家自然科学基金项目(41001369和41371480)
安徽省振兴人才计划项目资助
关键词
退耕湿地
重金属
分布特征
污染评价
wetlands after returning farmland
heavy metals
distribution characteristics
pollution evaluation