Zhang Hong-Ju, Zhao Ke-Li, Ye Zheng-Qian, Xu Bin, Zhao Wei-Ming, Gu Xiao-Bo, Zhang Hua-Feng
State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Lin'an 311300, China.
Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an 311300, China.
Huan Jing Ke Xue. 2018 Jun 8;39(6):2893-2903. doi: 10.13227/j.hjkx.201707115.
In recent years, the problem of soil pollution has become more and more serious. The problem of soil heavy metal pollution and its related human health risks has become a hot spot at home and abroad. is a unique high-grade woody nut and oil tree from China, and there are few reports on heavy metal pollution in plantation soils. Therefore, in order to study the spatial variability of heavy metals and the risk of pollution in soil and to promote the sustainable development of the industry, Lin'an, a typical plantation area, was selected for this study. A total of 188 soil samples were collected from the study area. We systematically studied the spatial heterogeneity of soil heavy metal content in the study area based on GIS technology, geostatistics, Moran's I, and other spatial analysis methods. The single factor pollution index method, the Nemerow comprehensive pollution index method, and the potential ecological risk assessment method were used to evaluate the heavy metal pollution in the study area. The results indicated that the mean content of soil cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and chromium (Cr) were 0.37, 40.76, 87.61, 30.10, 28.33, 56.57 mg·kg, respectively. The average values of Cd and Cu were 1.33 and 2.87 times of the background values, respectively, and the average content of other heavy metals did not exceed the background values. The results of the single factor Nemerow pollution index and potential ecological risk assessment methods showed that heavy metals in the study area exceeded the soil background values in some samples, and the second grade standard of soil environmental quality was exceed for Cd, Cu, Zn, Pb, and Ni in 31.38%, 31.38%, 2.65%, 0.53%, and 17.02% of the samples, respectively. This indicated that the soils in the study area had different accumulation characteristics for Cd, Cu, Zn, Pb, Ni, and Cr, and the local soil had reached pollution levels for Cd, Cu, Zn, Pb, and Ni. Among them, Cd was the most serious, reaching the degree of strong ecological damage, followed by Cu. In general, the heavy metal contents indicated a moderate degree of ecological damage. Based on the analysis of the semi-variance function, the Cd, Cu, and Ni in the soil were best fit with exponential models, the Zn and Pb were better fit with the Gaussian model, and Cr was consistent with the spherical model. Cd, Cu, Pb, Ni, and Cr had the strong spatial autocorrelation, with Nugget/Sill ratios of 12.1%, 4.6%, 14.9%, 2.6%, and 11.2%, respectively, while the Nugget/Sill ratio of Zn was 48.8%, indicating a medium spatial autocorrelation. Moran's I and Kriging interpolation results found that the heavy metals Cd, Cu, Zn, Pb, Ni, and Cr all had obvious spatial distribution patterns and local spatial aggregation phenomena. The high values of heavy metals in soils were mainly found in Taiyang, Daoshi, Qingliangfeng, Heqiao, and Tuankou, and the probability of the risk for contamination by Cd and Cu was higher in the study area. The high values of Cd, Cu, Zn, Ni, and Cr were mainly related to mining, while Pb was closely related to the application of potassium.
近年来,土壤污染问题日益严重。土壤重金属污染问题及其相关的人类健康风险已成为国内外研究的热点。[此处原文有缺失信息,未明确提及的树种名称]是中国特有的优质木本油料树种,关于其种植土壤重金属污染的报道较少。因此,为研究[树种名称]土壤中重金属的空间变异性及污染风险,推动[树种名称]产业可持续发展,本研究选取典型的[树种名称]种植区临安进行。研究区域共采集了188个土壤样本。基于GIS技术、地统计学、莫兰指数(Moran's I)等空间分析方法,系统研究了研究区域土壤重金属含量的空间异质性。采用单因子污染指数法、内梅罗综合污染指数法和潜在生态风险评价法对研究区域的重金属污染状况进行评价。结果表明,土壤中镉(Cd)、铜(Cu)、锌(Zn)、铅(Pb)、镍(Ni)和铬(Cr)的平均含量分别为0.37、40.76、87.61、30.10、28.33、56.57 mg·kg。Cd和Cu的平均值分别是背景值的1.33倍和2.87倍,其他重金属的平均含量均未超过背景值。单因子内梅罗污染指数和潜在生态风险评价结果表明,研究区域部分样本的重金属含量超过土壤背景值,Cd、Cu、Zn、Pb和Ni分别有31.38%、31.38%、2.65%、0.53%和17.02%的样本超过土壤环境质量二级标准。这表明研究区域土壤对Cd、Cu、Zn、Pb、Ni和Cr具有不同的累积特征,局部土壤Cd、Cu、Zn、Pb和Ni已达到污染水平。其中,Cd污染最为严重,达到强生态危害程度,其次是Cu。总体而言,重金属含量表明生态危害程度为中等。基于半方差函数分析,土壤中Cd、Cu和Ni最佳拟合指数模型,Zn和Pb较好拟合高斯模型,Cr符合球状模型。Cd、Cu、Pb、Ni和Cr具有较强的空间自相关性,块金值/基台值分别为12.1%、4.6%、14.9%、2.6%和11.2%,而Zn的块金值/基台值为48.8%,表明其空间自相关性中等。莫兰指数(Moran's I)和克里格插值结果表明,土壤中重金属Cd、Cu、Zn、Pb、Ni和Cr均具有明显的空间分布格局和局部空间聚集现象。土壤中重金属高值主要集中在太阳镇、岛石镇、清凉峰镇、河桥镇和湍口镇,研究区域Cd和Cu污染风险概率较高。Cd、Cu、Zn、Ni和Cr的高值主要与采矿活动有关,而Pb则与钾肥施用密切相关。