南京重工业园区周边区域地表灰尘重金属污染调查研究

Investigation on heavy metal pollution of surface dust insurrounding area of Nanjing heavy industry park

针对2020年9月至2020年10月在南京钢铁集团外采集的25个地表灰尘样品,使用手持式X射线荧光光谱仪(XRF)分析其中Cr、Mn、Fe、Cu、Zn、Hg、Pb、Sr、Zr、Mo这10种重金属元素含量,运用统计学方法、单因子指数、地累积指数对研究区土壤重金属污染程度进行评价,并采用正定矩阵因子分解模型解析了重金属污染源。结果表明,地表灰尘重金属平均含量为:Cr(260±14 mg·kg^(−1))、Mn(1550±22 mg·kg^(−1))、Fe(165000±1000 mg·kg^(−1))、Cu(67±9 mg·kg^(−1))、Zn(600±13 mg·kg^(−1))、Hg(16±6 mg·kg^(−1))、Pb(102±7 mg·kg^(−1))、Sr(275±10 mg·kg^(−1))、Zr(302±5 mg·kg^(−1))、Mo(13±3 mg·kg^(−1)),地累积指数平均值为2.13,区域整体呈中度污染,其中Hg为严重污染,Mo为重污染,Zn为中度污染,Cr、Fe、Pb为偏中污染,Mn、Cu、Sr为轻度污染,Zr无污染。研究区西北部及北部为重金属含量高值区,地表灰尘中重金属有较多富集。源解析分析表明研究区内地表灰尘重金属有3个主要来源:一是工业排放源,二是自然源及生活源,三是机动车排放源。其中工业排放源为主要来源,对重金属的贡献率为49.3%;其次为自然源及生活源和机动车排放源,贡献率分别为30.7%和20.0%。

25 soil dust samples collected outside Nanjing Iron and Steel Group,China,from September to October 2020 are analyzed by a handheld X-ray fluorescence spectrometer.Ten heavy metal elements,including chromium(Cr),magnesium(Mn),iron(Fe),copper(Cu),zinc(Zn),mercury(Hg),lead(Pb),strontium(Sr),zirconium(Zr)and molybdenum(Mo),are quantified,and their impacts on local soil pollution are assessed by various statistical models.In addition,a receptor model,positive matrix factorization(PMF),is used for source apportionment of these heavy metals.It is shown that the concentrations of these heavy metals in the ground surface soils are Cr(260±14 mg·kg^(−1)),Mn(1550±22 mg·kg^(−1)),Fe(1.65±0.01 mg·kg^(−1)),Cu(67±9 mg·kg^(−1)),Zn(600±13 mg·kg^(−1)),Hg(16±6 mg·kg^(−1)),Pb(102±7 mg·kg^(−1)),Sr(275±10 mg·kg^(−1)),Zr(302±5 mg·kg^(−1))and Mo(13±3 mg·kg^(−1)),respectively.Their averaged surface accumulation index is 2.13,indicating a moderate level of pollution.Individually,Hg is severely polluted,Mo is heavily polluted,Zn is moderately polluted,Cr,Fe and Pb are slightly-to-moderately polluted,Mn,Cu and Sr are slightly polluted,Zr is below the pollution level.It is found that most of the high concentration samples are taken from the north and northwest parts of the study area,where heavy metals are prone to accumulation.Three major sources of heavey metals in the study area are identified by the PMF analysis:industrial emissions(49.3%),domestic activities(30.7%)and automobile emissions(20.0%).