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城市土壤重金属污染多元统计及空间评估 总被引:1,自引:0,他引:1
为确定徐州市城区土壤重金属的污染情况,对167个城市土壤样品的Mn,Fe,Ni,Cu,Zn,Cd和Pb等7种重金属元素进行多元统计和空间分析。结果表明,7种重金属元素中,Ni,Cu,Zn,Cd,Pb含量均高于背景值。聚类分析和因子分析显示,研究区域土壤中Pb,Cd,Cu,Zn具有相似来源,Ni,Fe,Mn具有相似来源。Pb,Cd,Cu,Zn,Mn,Ni的块基比在0.25~0.75之间,表明变量具有中等程度的空间相关性,其空间变异性同时受土壤母质和人类活动的影响。研究区域土壤中,Zn,Cd,Pb的空间分布基本一致,同时受到交通运输和工业排放的影响;道路交通污染为研究区域Cu的主要来源。Fe和Ni同时受土壤母质和人类活动的影响,徐州钢铁厂附近区域土壤Fe含量整体偏高,在市中心主要交通干道附近表土中,Fe也表现出一定量的富集,Mn主要来自于土壤母质。 相似文献
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Spatial distribution of soil heavy metal pollution estimated by different interpolation methods: accuracy and uncertainty analysis 总被引:15,自引:0,他引:15
Mapping the spatial distribution of contaminants in soils is the basis of pollution evaluation and risk control. Interpolation methods are extensively applied in the mapping processes to estimate the heavy metal concentrations at unsampled sites. The performances of interpolation methods (inverse distance weighting, local polynomial, ordinary kriging and radial basis functions) were assessed and compared using the root mean square error for cross validation. The results indicated that all interpolation methods provided a high prediction accuracy of the mean concentration of soil heavy metals. However, the classic method based on percentages of polluted samples, gave a pollution area 23.54-41.92% larger than that estimated by interpolation methods. The difference in contaminated area estimation among the four methods reached 6.14%. According to the interpolation results, the spatial uncertainty of polluted areas was mainly located in three types of region: (a) the local maxima concentration region surrounded by low concentration (clean) sites, (b) the local minima concentration region surrounded with highly polluted samples; and (c) the boundaries of the contaminated areas. 相似文献
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采用涂刷法制备铱、钌摩尔比(Ir∶Ru)分别为1∶2、1∶1和2∶1的3种RuO2-IrO2/Ti修饰电极。5g/L苯酚溶液中循环伏安(CV)曲线测试结果表明,Ir∶Ru为1∶2的RuO2-IrO2/Ti修饰电极没有出现明显的氧化峰,而Ir∶Ru分别为1∶1、2∶1的RuO2-IrO2/Ti修饰电极分别在0.83、0.90V处出现明显的氧化峰。0.5mol/L硫酸溶液中的极化曲线测试结果表明,Ir∶Ru分别为1∶2、1∶1、2∶1的3种RuO2-IrO2/Ti修饰电极的析氧电位分别为1.20、1.25、1.35V。一定条件下的苯酚降解试验结果表明,160min后Ir∶Ru分别为1∶2、1∶1、2∶1的3种RuO2-IrO2/Ti修饰电极的苯酚去除率分别达到74.3%、82.3%和94.6%。可见,Ir∶Ru为2∶1的RuO2-IrO2/Ti修饰电极的析氧电位最高,苯酚去除率最高,电催化效果最好。 相似文献
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