铅锌尾矿库生态修复评价指标体系的构建及验证研究

发布时间：2018-12-23 08:50

【摘要】：随着中国经济的快速发展,铅锌矿作为重要的矿产资源被广泛的开采应用在诸多领域,然而在开采过程中产生的尾矿由于其重金属含量,养分贫瘠等特点导致了铅锌矿区以及周围生态环境的生态破坏和环境污染尤其是重金属污染,因此,尾矿作为一个特殊的矿山废弃地,其生态修复工作不断受到世界各国的重视,我国也投入了大量资金对尾矿库的生态修复进行不断的研究,然而至今,国家对尾矿废弃地尤其是铅锌尾矿废弃地还未出台相应的修复标准,铅锌尾矿生态修复后的效果评价成了生态修复工作的难点和热点,因此对生态修复工程修复之后评价指标体系的构建及研究十分必要,其修复效果评价工作可以为后续修复工作提供反馈和对同类型的尾矿废弃地的生态修复效果评价工作提供借鉴和指导。我国南方地区的铅锌尾矿库由于其特殊的地理环境,其在生态修复方面有着不同侧重点,在分析了国内外金属尾矿及矿山废弃地生态修复评价指标的构建和评价方法以及在野外实地调查、资料搜集的基础上,并结合相关专家老师意见之后,选取了铅锌尾矿生态修复效果评价指标,评价指标包括土壤理化性质、植物群落性状和重金属污染状况三个方面,通过层次分析法确定各指标的权重,最后以资兴市大脚岭铅锌尾矿库的生态修复工程为例进行实证评价,运用综合评价法和模糊分析法给出了评价结果。主要内容如下:(1)分析了我国铅锌尾矿的特点以及对生态环境造成的影响,总结并归纳了我国铅锌尾矿废弃地生态修复技术的研究进展以及生态修复综合评价的研究进展。(2)以资兴市大脚岭铅锌尾矿库生态修复工程为例,实地调查并分析了其在采取了一系列修复措施之后的近三年的土壤环境改善情况和植物群落生长状况。结果显示土壤理化性质维持在中等水平,土壤养分状况有所改善改善,但不明显,植物生长状况相对较好,物种相对丰富,2014年、2015年、2016年植被覆盖率分别在75%、82%、97%,覆土层重金属含量虽然有所增加,但是清洁范围以内,只有Cd含量有一定量的超标。人工湿地进出水中Pb、Zn、Cu、Cd四种重金属含量已远远低于地表水III类标准值,表明继续采用此系统是可行的;对土壤微生物群落多样性分析表明,修复区和未污染区域的微生物多样性差异不明显,土壤环境质量良好。(3)对在铅锌尾矿生态修复后的综合评价一般方法研究的基础上,从土壤理化性质、植物群落性状和重金属污染状况三个方面选取了包括容重、pH、有机质、碱解氮、有效磷、速效钾、丰富度指数、植被覆盖率、Pb污染指数、Zn污染指数、Cu污染指数、Cd污染指数在内的12个指标,通过构建基于层次分析法的铅锌尾矿生态修复效果评价模型确定了各级指标的权重。(4)根据综合评价法得出2014年、2015年、2016年最终评价得分为3.7101、4.1829、4.3733,和模糊评价法得出的一般、良好、良好具有高度的吻合度,说明构建的评价指标体系及评分标准对铅锌尾矿库生态修复效果评价具有一定的指导作用。
[Abstract]:With the rapid development of China's economy, the lead-zinc mine, as an important mineral resource, is widely used in many fields, but the tailings produced during the mining process are due to their heavy metal content, the characteristics of poor nutrient and the like lead to the ecological destruction of the lead-zinc and the surrounding ecological environment and the environmental pollution, in particular the heavy metal pollution, China has also invested a lot of funds to study the ecological restoration of the tailings pond, yet so far, the country has not issued the corresponding repair standard for the tailings, especially the lead-zinc tailings, The result of the ecological restoration of lead-zinc tailings has become the difficult point and the hot spot of the ecological restoration work, so it is necessary to construct and study the evaluation index system after the restoration of the ecological restoration project. The repair effect evaluation work can provide reference for the follow-up work and provide reference and guidance for the evaluation of the ecological restoration effect of the same type of tailings. Due to its special geographical environment, the lead-zinc tailings pond in the southern part of China has a different focus on the ecological restoration, and the construction and evaluation method of the index of the ecological restoration and evaluation of the metal tailings and the mine in the home and abroad are analyzed, and the field investigation is conducted in the field, On the basis of the data collection and combining with the relevant expert's opinions, the evaluation index of the ecological restoration effect of lead-zinc tailings is selected, and the evaluation indexes include three aspects of soil physical and chemical properties, plant community character and heavy metal pollution condition, and the weight of each index is determined through the level analysis method, The results of the evaluation are given by using the comprehensive evaluation method and the fuzzy analysis method. The main contents are as follows: (1) The characteristics of lead-zinc tailings in China and the impact on the ecological environment are analyzed, and the research progress and the progress of the comprehensive evaluation of the ecological restoration of lead-zinc tailings in China are summarized and summarized. (2) In order to improve the soil environment and plant community growth in the last three years after a series of repair measures have been carried out. The results show that the physical and chemical properties of the soil are maintained at a moderate level, the soil nutrient status is improved, but it is not obvious that the plant growth is relatively good and the species are relatively rich. In 2014, the vegetation coverage rate in 2016 and 2016 is 75%, 82% and 97%, respectively. The heavy metal content of the overlying soil layer has increased, but within the cleaning range, only a certain amount of the Cd content is in excess of the standard. The heavy metal content of Pb, Zn, Cu and Cd in the water and water of the artificial wetland is much lower than the standard value of the surface water III, indicating that the system is feasible, and the diversity analysis of the soil microbial community shows that the difference between the microbial diversity of the repair area and the uncontaminated area is not obvious, The soil environment is of good quality. (3) On the basis of the general method of comprehensive evaluation after the ecological restoration of lead-zinc tailings, three aspects, including bulk density, pH, organic matter, alkali solution nitrogen, effective phosphorus, quick-acting potassium and richness index, are selected from three aspects of soil physical and chemical properties, plant community character and heavy metal pollution condition. 12 indexes including vegetation cover, Pb pollution index, Zn pollution index, Cu pollution index and Cd pollution index are established, and the weight of all levels of index is determined by constructing the evaluation model of the ecological restoration effect of lead-zinc tailings based on the analytic hierarchy process. (4) According to the comprehensive evaluation method, the final evaluation in 2014, 2015 and 2016 was divided into 3. 7101, 4. 1829, 4. 3733, and the general, good, good and high degree of coincidence from the fuzzy evaluation method. The evaluation index system and the evaluation criteria for the evaluation of the ecological restoration effect of the lead-zinc tailing reservoir have a certain guiding role.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X171.4;X82

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