【摘要】 降雨条件下形成的农田径流是土壤与水体间物质交换的一种重要形式,是农业非点源污染的重要组成部分。2007-2008年,在强降雨条件下,定点采集了天津市郊农田降雨径流样品64个,并对其重金属含量进行了分析测定。结果显示:研究区农田降雨径流中Cr、Ni、Cd、Zn等4项重金属含量服从对数正态分布,Cu、As、Pb为偏态分布。研究区农田径流中各重金属变异系数普遍较高,数据离散程度较大,除As外,其他各重金属之间具有显著相关性。主成分分析结果显示,研究区农田降雨径流重金属可提取3个主成分,第一主成分包含Cr、Ni和Zn,第二主成分包含Cu、Cd、Pb,第三主成分则集中反映了As的作用,表明研究区农田径流重金属可能主要来源于火力发电、电镀工业以及污水灌溉、化肥等农业投入品施用。更多还原

【Abstract】 Farmland runoff is an important form of material exchange in the soil-water interface under rainfall condition,which is also the most important part of agricultural non-point contamination source.Sixty-four samples of farmland runoffs were systematically collected in the Tianjin suburban areas after strong rainfall from 2007 to 2008.The concentrations of heavy metal in the collected samples were determined by ICP-MS.The results showed that the concentrations of Cr、Ni、Cd and Zn in the farmland runoff were in lognormal distribution.The concentrations of Cu、As、Pb were in skew distribution.The coefficients of variation of heavy metals in farmland runoff were almost big,which indicates that the degree of scatter of heavy metal dates was greater and the concentrations of heavy metal varied greatly.There were significant relationships between heavy metals except As.The results of principal component analysis revealed that three components could be chosen to represent the data set.The first factor include Cr,Ni and Zn,the second factor include Pb and Hg,while As was strongly related to the third component.It was concluded that thermo-power generation,electroplate industrial and wastewater irrigation,fertilizer application were the primary source of the heavy metals in farmland runoff.更多还原