博斯腾湖流域绿洲农田土壤重金属污染及潜在生态风险评价

发布时间：2018-03-02 09:00

本文关键词： 农田土壤重金属污染评价生态风险博斯腾湖流域　出处：《地理学报》2017年09期 　论文类型：期刊论文

【摘要】：新疆博斯腾湖流域绿洲采集195个农田土壤样品,测定其中As、Cd、Cr、Cu、Mn、Ni、Pb和Zn等8种重金属元素的含量,基于地统计法分析农田土壤重金属空间分布规律,采用污染负荷指数(PLI)和潜在生态风险指数(RI)评价农田土壤重金属污染和潜在生态风险程度,并对重金属的来源进行讨论。结果表明:(1)博斯腾湖流域农田土壤Cd、Cr、Cu、Ni、Pb和Zn含量平均值分别超出新疆土壤背景值的1.67倍、1.13倍、1.15倍、1.29倍、2.11倍和1.65倍。(2)农田土壤中8种重金属元素空间分布基本呈现岛状分布格局,各金属元素在部分区域出现高值区,表明研究区人类活动对农田土壤环境具有负面效应。(3)农田土壤Pb呈现中度污染,Cd、Cr、Cu、Ni和Zn轻度污染,Mn轻微污染,As无污染。农田土壤重金属污染负荷指数的平均值为1.09,呈现轻度污染态势。(4)各重金属元素单项生态风险指数平均值从大到小依次为:Cd、Ni、As、Cu、Pb、Cr、Zn。综合生态风险指数平均值为18.63,处于轻微生态风险态势。从生态风险程度的区域差异来看,各县生态风险指数从大到小依次为:和硕县、博湖县、焉耆县、和静县。(5)农田土壤Cr、Cu、Mn、Ni与Zn主要受到土壤地球化学成因的控制,As、Cd和Pb主要受到人类活动的影响。Cd与Pb是研究区主要的污染因子,研究区农田土壤中Cd与Pb污染必须关注。
[Abstract]:195 farmland soil samples were collected from oasis of Bosten Lake Basin, Xinjiang, and the contents of 8 heavy metals, such as Aspergectadecrhium crassifolia, CuMnMnPh, Pb and Zn, were determined. The spatial distribution of heavy metals in farmland soil was analyzed based on the method of geostatistics. The pollution load index (PLI) and the potential ecological risk index (Ri) were used to evaluate the degree of heavy metal pollution and potential ecological risk in farmland soil. The results show that the average content of CD ~ (2 +) Cr ~ (2 +) Cu ~ (2 +) Ni ~ (2 +) Pb and Zn in farmland soil in the Bosten Lake basin is 1.67 times higher than that in Xinjiang soil background value 1.67 times ~ 1.13 times ~ 1.15 times ~ 1.29 times ~ 1.29 times ~ 2.11 times and 1.65 times 路L ~ (2)) respectively) of 8 kinds of heavy metals in farmland soil. The spatial distribution of metal elements basically presents an island pattern. Each metal element has a high value area in some areas, The results showed that there was negative effect of human activities on farmland soil environment. (3) Pb in farmland soil showed moderate pollution (CD ~ (2 +) Cr ~ (2 +)) Cu ~ (2 +) Ni and Zn ~ (2 +) slightly polluted mn ~ (2 +), and the average value of heavy metal pollution load index was 1.09 (P < 0.05). The average value of individual ecological risk index of each heavy metal element is from large to small. The average value of comprehensive ecological risk index is 18.63, which is in a slight ecological risk situation. From the regional difference of ecological risk degree, the average value of comprehensive ecological risk index is 18.63. The ecological risk index of each county from big to small is: Hesu County, Bohu County, Yanqi County, Soil Cr ~ (2 +) Cu ~ (2 +) mn ~ (2 +) Ni and Zn are mainly controlled by soil geochemistry. CD and Pb are mainly affected by human activities. CD and Pb are the main pollution factors in the study area. The pollution of CD and Pb in farmland soil in the study area must be paid attention to.
【作者单位】：新疆师范大学地理科学与旅游学院;新疆干旱区湖泊环境与资源实验室新疆师范大学;新疆大学化学与化工学院;
【基金】：国家自然科学基金项目(41561073) 新疆杰出青年科技人才培养项目(qn2015jq003)~~
【分类号】：X53;X826

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