中南大型有色金属冶炼厂周边农田土壤重金属污染特征研究  

Heavy Metal Contamination Characteristics in Soils Around a Nonferrous Metal Smelter in Central Southern China

作　　者：曹雪莹[1,2] 张莎娜[1] 谭长银[1] 胡鹏杰[2] 崔旭[2] 周通[2] 吴龙华[2] 骆永明[2] 

机构地区：[1]湖南师范大学资源与环境科学学院,长沙410081 [2]中国科学院土壤环境与污染修复重点实验室(南京土壤研究所),南京210008

出　　处：《土壤》2015年第1期94-99,共6页Soils

基　　金：国家高技术研究发展计划(863)项目(2012AA06A204);环保公益性行业科研专项(201109056)资助

摘　　要：以中南地区某大型有色金属冶炼厂周边耕地为对象,采集0~20 cm表层土壤,测定其基本性质及重金属浓度,分析了重金属元素间及重金属污染程度与距冶炼厂远近的相关关系,以判别研究区土壤重金属污染来源及空间分布规律。结果表明,研究区土壤呈酸性,土壤重金属污染以Cd为主,与当地土壤环境背景值和国家土壤环境质量二级标准相比,超标率分别达60.9%、86.1%。Cu、Zn、Cr、Ni等元素的污染较轻,Pb则未超标。内梅罗综合污染指数法对水田土壤重金属的风险评价显示该区属于安全的点位仅占8.7%,农产品生产存在较高风险。单因素方差分析显示旱地与水田土壤重金属浓度差异不显著,说明耕作方式不是造成该区重金属分布差异的主要原因。土壤Cd与Pb、Zn浓度显著相关,且与距冶炼厂的距离呈显著负相关,指数和幂函数均能很好地拟合重金属浓度随距离变化的分布模式,说明三者可能均来源于冶炼厂的降尘污染。The characteristics of heavy metal pollution in 0-20 cm soil layers of the farmlands surrounding a nonferrous metal smelter in central southern China were assessed from three directions： northwest, southwest and southeast. The correlation analyses among heavy metal elements and between heavy metal concentrations and the distance to the smelter were conducted to identify metal spatial distribution and the pollution source. The results showed that the soils in this area were mainly acidic and seriously contaminated by Cd. Approximately 60.9% and 86.1% of the soils exceeded local soil environmental background values and the National Soil Environmental Quality Standards, respectively. The soil was polluted lightly by Cu, Zn, Cr and Ni, but not polluted by Pb. According to the “Nemerow comprehensive pollution index”, only 8.7% of the samples were within the level of “security”, which suggested that crop production in this area faces serious risk of heavy metal contamination. One factor analysis of variance demonstrated that the difference of heavy metal concentrations in dry land and paddy was not significantly different, indicating that farming methods are not the main cause of the different distribution of heavy metals in this area. Soil Cd, Pb and Zn were significantly correlated and showed remarkable negative relationship with the distance to the smelter. Exponential and power functions can be used to fit heavy metal distribution patterns with the distance, indicating that these pollutants might come from the high metal containing dust of the smelter.

关 键 词：铅锌冶炼 土壤重金属 变异特征 风险评价 

分 类 号：X50[环境科学与工程—环境工程] X53