煤炭基地村庄复垦土壤重金属污染生态风险评价

发布时间：2018-01-21 16:43

本文关键词： 复垦村庄重金属污染潜在危害指数生态风险　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：我国黄土高原煤炭基地范围内,由于煤炭开采带来的灾害性问题以及矿产资源被压占等一系列原因,有大量村庄土地被或即将被废弃,开展村庄的土地复垦成为补充耕地、改善土壤环境的有效手段。而重金属含量作为土壤质量评价中的重要指标,对村庄土地复垦质量监测与评价具有重要意义。通过明确复垦土壤中的重金属污染情况,对改良复垦后耕地质量和科学地提出复垦措施有非常重要的意义。本文选取西郜村为研究区域,基于潜在生态危害指数法,对复垦村庄土壤中的重金属含量进行生态风险评价,旨在综合全面地反应出土壤中重金属污染的生态风险程度以及空间分布规律,为科学地提出复垦措施提供依据。本研究首先对研究区土壤的重金属含量进行采集及处理,并从土层深度、不同元素等多角度对比分析研究区土壤重金属含量现状。然后,采用生态危害指数法对研究区土壤重金属含量进行综合评价,全面地分析不同土层土壤和主要污染因子的生态风险程度以及其空间分布规律。最后,分析土壤重金属污染的污染来源以及生态风险评价的影响因素,并提出在村庄复垦中可以采取的措施。通过以上研究,本文可得到的研究结论如下:(1)西郜村土壤重金属综合污染程度和潜在生态风险等级在总体上均处于中等程度。(2)从单个要素上来看,Hg元素无论是在污染程度还是生态风险等级上均处于较高程度,应该在村庄复垦过程中积极采取措施减轻其生态危害。(3)由于受到煤炭开采、工业活动的影响,西郜村土壤重金属污染生态风险等级为中等程度的空间分布主要集中于村中90年以后宅基地和村庄东南角,而耕地及50年以前宅基地所受污染较轻。(4)0~20cm土层由于受到人为活动的影响较大,在这一层重金属综合污染程度和生态风险等级明显高于20~40cm土层,并且生态风险等级为中等的分布范围广。(5)潜在生态危害指数法在本文中的应用可以综合而全面地反映复垦村庄土壤中重金属的综合污染和和生态风险程度,为提升复垦后耕地的质量和采取合理复垦措施提供依据。
[Abstract]:In the coal base of the Loess Plateau in China, a large number of village lands have been abandoned or will be abandoned due to the disastrous problems caused by coal mining and the pressure of mineral resources. Land reclamation in villages has become an effective means to supplement cultivated land and improve soil environment. Heavy metal content is an important index in soil quality evaluation. It is of great significance to monitor and evaluate the quality of land reclamation in villages. It is of great significance to improve the quality of cultivated land after reclamation and put forward the reclamation measures scientifically. This paper selects Xi Gao Village as the research area based on the potential ecological hazard index method. In order to comprehensively reflect the ecological risk degree and spatial distribution of heavy metal pollution in soil, the ecological risk assessment of heavy metal content in reclaimed village soil was carried out. This study firstly collected and treated the heavy metal content of the soil in the study area, and from the depth of soil layer. The present situation of soil heavy metal content in the study area was analyzed from different elements and so on. Then, the ecological hazard index method was used to evaluate the soil heavy metal content in the study area. The ecological risk degree and spatial distribution of soil and main pollution factors in different soil layers were comprehensively analyzed. Finally, the pollution sources of soil heavy metal pollution and the influencing factors of ecological risk assessment were analyzed. And put forward the measures that can be taken in the village reclamation. The conclusions of this paper are as follows: 1) the comprehensive pollution degree and potential ecological risk level of heavy metals in Xigao village are all in the middle level on the whole. The Hg element is in a high degree in both the pollution degree and the ecological risk grade. It is necessary to take active measures in the process of village reclamation to reduce its ecological harm. 3) due to coal mining. The influence of industrial activities, the ecological risk of soil heavy metal pollution in Xigao village was moderate in spatial distribution, which mainly concentrated on the homestead and southeast corner of the village after Yu Cun's middle 90 years. On the other hand, the soil layer of cultivated land and its homestead was slightly polluted 50 years ago because of the influence of human activities. The comprehensive pollution degree and ecological risk grade of heavy metals in this layer were obviously higher than that in 200-40cm soil layer. And the ecological risk grade is medium. The distribution range is wide. The application of potential ecological hazard index method in this paper can comprehensively and comprehensively reflect the comprehensive pollution and ecological risk of heavy metals in reclaimed village soil. To improve the quality of cultivated land after reclamation and to take reasonable reclamation measures to provide the basis.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X825

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