冶炼行业企业周边土壤重金属分布特征及潜在生态风险评价

    Distribution characteristics of heavy metals in soils around smelting enterprises and potential ecological risk assessment

    • 摘要: 为研究工业园区周边不同土地利用方式下土壤重金属的污染分布特征,以云南某典型冶炼行业企业周边为研究区,以不同土地利用方式下的土壤为研究对象,通过单项污染指数法、潜在生态风险指数法综合评价农用地、林地、荒地土壤8种重金属的污染状况,通过相关性分析及主成分分析对污染源进行探究。研究结果表明:研究区土壤Cd、Cr、Cu、Ni、Pb、Zn、Hg、As含量平均值均超过云南省土壤重金属背景值; 3种土地利用方式下,农用地土壤重金属的单项污染指数(Cr、Ni除外)均值、综合潜在生态风险等级均明显大于林地和荒地; 整个区域内土壤重金属综合潜在生态风险等级为强和极强,基本呈现越远离工业园区,土壤重金属综合潜在生态风险等级越低的特征; 根据土壤重金属相关性分析及主成分分析,在3种土地利用方式下,林地和荒地Cd、Pb、Zn、Hg、As主要为工业源,农用地Cd、Pb、Zn、Hg、As、Cu还叠加农业源,而Cr、Ni主要受成土母质的控制。通过研究,能够了解重金属的动态变化以及土地利用方式合理性,从而为该区及周边土壤重金属污染防治以及安全利用提供科学依据及指导。

       

      Abstract: In order to investigate the distribution characteristics of heavy metal pollution in soils under different land use types of surrounding industrial parks, the authors in this paper focused on typical smelting industry areas in Yunnan Province and took targets soils with various land uses as the study object.The contamination status of eight heavy metals in agricultural land, forest land, and wasteland was comprehensively evaluated by single pollution index method and potential ecological risk index.Correlation analysis and principal component analysis were utilized to explore the sources of pollution.The results indicate that the average content of Cd, Cr, Cu, Ni, Pb, Zn, Hg, As in soils of the study area all exceeded the background value of heavy metals in soils of Yunnan Province.Among the three land-use types, agricultural land exhibited a significant higher mean single pollution index (excluding Cr and Ni) and higher comprehensive potential ecological risk level compared with forest land and wasteland. The overall comprehensive potential ecological risk level for heavy metals in the entire region was classified as strong or extremely strong. A clear spatial pattern emerged, showing that the comprehensive potential ecological risk level generally decreased with increasing distance from the industrial park. Correlation analysis and PCA indicated that Cd, Pb, Zn, Hg, As, Cu were primarily derived from industrial sources for forest land and wasteland, and Cd, Pb, Zn, Hg, As, Cu were superimposed with agricultural sources for agricultural land. Cr and Ni were mainly controlled by the soil parent material. Understnding of the dynamic changdes in heavy metal concentrations as well as the rationality regarding land utilization methods could be strengthened throug the research, and it could provide scientific basis and guidance for preventing soil heavy metal pollution in this area.

       

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