兰州市降尘重金属的来源与生态风险研究  

Source apportionment and ecological risks of heavy metal elements in the dustfall of Lanzhou City

作　　者：方文稳 张丽[1] Dembele Blaise 张慧荣[1] 李瑞博[1] 张成君[2] 

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]兰州大学地质科学与矿产资源学院,兰州730000

出　　处：《兰州大学学报（自然科学版）》2016年第1期24-30,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金面上项目(41173015);教育部博士点基金项目(20100211110020)

摘　　要：采用X荧光光谱分析法对兰州市降尘中Cu、Zn、Pb、Ni、Cr、As等元素进行了分析.结果表明:降尘中Cu、Zn、Pb、Ni、Cr、As的平均质量分数分别是74.2、317.7、31.9、44.0、114.7、42.9 mg/kg,均高于兰州市土壤元素背景值,其中As、Zn超标最为突出.利用因子分析法和元素等值线图分析了兰州市降尘重金属的来源,结果表明:Cr是自然来源,无污染;Ni主要是工业与自然的混合来源;As来源于燃煤;Pb可能主要来源于含铅土壤的再悬浮;Cu、Zn主要来源于机动车辆.利用地积累指数法和潜在生态风险指数法对兰州市降尘中各元素进行评价.地积累指数法评价结果显示Zn、As属于偏中度污染,Cu、Pb、Ni为轻度污染,Cr无实际污染.潜在生态风险指数法评价结果显示除个别地区As元素达到较高生态危害外,其他元素都属于轻度潜在生态危害.Lanzhou City dustfall in Cu,Zn,Pb,Ni,Cr,As and other elements were analyzed by using X-Ray fluorescence spectrometry.The results showed that the mean concentrations of Cu,Zn,Pb,Ni,Cr,As were74.2,317.7,31.9,44.0,114.7,42.9 mg/kg respectively,and were higher than the background value of soil elements in Lanzhou,and As,Zn exceeded the standard of the most prominent.Factor analysis method and contour line graph of elements analysis were used to determine the source of heavy metals in the dust of Lanzhou City.The results showed that Cr come from natural sources and has no form of pollution.The source of Ni is mainly a mixture of natural and industrial.As come from coal-fire.Pb mainly come from the resuspension soil of lead.Cu,Zn mainly comes from motor vehicles.The environmental risk of each elements pollution in street dust of Lanzhou City was assessed by Geo-accumulation Pollution Index and Potential Ecologically Risk Index.The assessment results of Geo-accumulation Pollution Index showed that Zn and As belonged to moderate pollution,Cu,Pb,Ni is slightly polluted,and Cr as practically uncontaminated.The potential ecologically risk assessment results showed that apart from individual regions.As elements to achieve a higher ecological harm other elements belong mild potential ecological hazards.

关 键 词：降尘 重金属 因子分析 生态风险 兰州市 

分 类 号：X53[环境科学与工程—环境工程] X820.4