摘要
为探究西北地区某重工业区典型气象下大气降尘重金属的污染特征及污染来源,作者采集研究区域内18个点位共54份有效降尘样品,分析了样品中重金属含量特征及空间分布特征,采用富集因子法和潜在生态风险指数法对研究区内重金属污染特征进行评估,并结合相关性分析和正定矩阵因子分析模型(PMF)解析了重金属污染来源.结果表明,采样期间研究区域内大气降尘中重金属Cd、Cr、Co、As、Mn、Ni、Cu、Pb、Zn 的平均含量分别为 118.05、931.69、20.53、905.29、1 478.96、784.27、1 012.10、3 162.23 和 5 751.61 mg/kg,均高于甘肃省土壤背景值;此外,空间污染特征上表现为工业区＞城郊区＞居民区的趋势,污染程度特征上表现为各功能区中从Cd、As、Pb、Ni、Cu和Zn的污染富集程度高,As、Cd和Co的潜在生态风险较大;重金属来源解析结果表明,大气降尘中重金属主要来源于土壤扬尘源(37.7％)、冶金工业源(31.2％)、工业加工混合源(13.5％)、交通源(10.1％)和燃煤源(7.6％).
Abstract
In order to explore the pollution characteristics and sources of heavy metal elements in the atmospheric dustfall of a typical heavy industrial city in northwest China,54 effective dustfall samples were collected from 18 points in the study ar-ea.The enrichment factor method and potential ecological risk index method were utilized to evaluate the characteristics of heavy metal pollution.Subsequently the sources of heavy metal pollution were specified by the correlation analysis and posi-tive matrix factor analysis(PMF).The results showed that the average contents of heavy metal elements Cd,Cr,Co,As,Mn,Ni,Cu,Pb,Zn in the atmospheric dustfall samples were 118.05,931.69,20.53,905.29,1 478.96,784.27,1 012.10,3 162.23,5 751.61 mg/kg,respectively,which were all higher than the soil background values of Gansu Province.In addition,the spatial pollution characteristics showed a trend of industrial areas＞suburban areas＞residential areas,and the pollution degree charac-teristics showed a high concentration of Cd,As,Pb,Ni,Cu,and Zn in various functional areas,while the potential ecological risks of As,Cd,and Co were relatively high.The source analysis results showed that the heavy metals in the atmospheric dust-fall mainly come from dust sources(37.7％),metallurgical industry sources(31.2％).mixed sources(13.5％),transportation sources(10.1％)and coal sources(7.6％).
维普
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