海南昌化铅锌矿废弃地及其周边土壤重金属统计分析与污染评价

发布时间：2017-12-26 22:08

本文关键词：海南昌化铅锌矿废弃地及其周边土壤重金属统计分析与污染评价　出处：《海南师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：铅锌矿产作为人类工业活动必不可少的自然矿产资源,对我国的经济发展有着十分重要的作用。但是,由于我国长期忽略铅锌矿产资源开发过程中对环境造成的污染,因而造成了严重的铅锌矿尾矿污染问题。本文在基于前人研究的基础上,旨在对昌化铅锌矿废弃地及其周边土壤的重金属污染治理提供必要的理论依据。通过对海南昌化铅锌矿废弃地及其周边土壤进行野外调查,并采集56份土壤样品,对废弃地土壤中重金属含量进行测定,利用统计学方法对研究区重金属含量进行分析,揭示研究区内重金属污染的统计学规律;运用单因子污染指数法、内梅罗综合污染指数法、地累积指数法以及潜在生态风险指数法对海南昌化铅锌矿废弃地及其周边土壤的环境质量状况进行合理的分析评价。得出以下主要结论:(1)海南昌化铅锌矿废弃地及其周边土壤中重金属元素Cr的变异系数最低,为52.76%,变异系数均相对较小,这表明重金属元素Cr分布相对比较均匀,离散程度较低;而Cu、Cd、Pb的离散程度很高,分布很不均匀;Ni、Zn和As离散程度最高,分布最为不均匀。重金属元素Cu、Zn、Cd、Pb平均值的含量都相当高。分别是海南省土壤背景值的35.57、52.66、363.40、144.25倍,其中含量倍数CdPbZnCu;Ni的平均含量略高于海南土壤背景值,Cr和As的平均含量均明显低于海南省土壤背景值,但其最大值均超过了海南土壤背景值。(2)重金属元素Cu-Pb和Zn-Cd呈高度相关性,其相关系数在0.9以上,来自同一污染源的可能性非常大,源自于铅锌矿产资源的开发所致。Cr、As与各个重金属元素的相关性均不高,但Cr与As则有一定的相关性;主成分分析表明三个成分中的载荷最高的重金属元素相互之间都呈现出了高度的相关性,可见他们的污染造成都是来自相同因素。聚类分析表明,Zn-Cd为一类,Pb-Cu为一类,而Ni-As-Cr也为一类。(3)重金属元素含量半变异函数模型拟合表明,As、Cr的半方差函数为球状模型,而重金属元素Cu、Ni、Pb以及Zn的半方差函数模型为高斯模型,仅重金属元素Cd的半方差函数模型为指数模型。研究区域内重金属均表现出强烈的空间相关性,空间变异绝大部分是由成土母质、气候、地形等结构性因素引起。重金属元素As含量较高的地区为复垦区和尾矿区;Cd与Zn的最高值集中于三个位置,分别为尾矿区东部、服务区和河流转弯处;Pb和Cu含量最高的区域集中于桥梁两侧、服务区、居民点周围、尾矿区东部并延伸至整个西北部大片区域和复垦区中西部;重金属元素Cr主要分布于尾矿区的西北部、废石场的周边、服务区的周边以及西南部的河流尾段,Ni则在研究区域中呈零散分布状态,且同时这两种重金属元素的含量均低于国家土壤质量标准三级标准。(4)单因子污染指数评价结果表明,依据国家土壤质量标准三级标准,重金属元素Cd在研究区域内几乎全部为严重污染级别,Cu污染较轻,仅在桥梁周围以及沿道路向南部存在轻度污染。重金属元素Pb与Zn在研究区域的东北部均为清洁区域,Pb严重程度的污染区域为北部尾矿区、复垦区周边并向西北部延伸的区域,重金属Zn严重级别的污染主要集中在服务区、桥梁及其左侧、尾矿区东部、复垦区北部以及河流转弯处并向西北延伸;内梅罗综合污染评价结果表明,重金属元素Cu的内梅罗综合污染指数为1.48,属于轻度污染级别,而Zn、Cd及Pb的内梅罗综合污染指数分别为16.69、61.46及23.33,均为重度污染级别;地累积指数污染评价结果表明,Cd污染程度最为严重,为极严重污染的级别,其次为Pb,基本全部处于极严重污染级别,重金属元素Cu与Zn对于研究区域的污染相对较轻;7种重金属潜在生态风险程度依次为CdPbZnCuAsNiCr,其中,重金属Cd的潜在生态风险指数值为363.370,污染程度达到严重等级,重金属Pb的潜在生态风险指数为123.317,属于较重的污染风险程度,其他元素潜在风险指数均低于40,属轻微污染风险程度,综合潜在生态风险指数达到了514.596,属重度污染程度,对于当地生态危害很高。其中Cd的贡献率最大,达到了70.62%。
[Abstract]:As an essential natural mineral resource in human industrial activities, lead and zinc minerals play an important role in the economic development of our country. However, due to the long-term neglect of the environmental pollution caused by the development of lead-zinc mineral resources in China, the serious pollution of lead and zinc mine tailings is caused. On the basis of previous studies, this paper aims to provide the necessary theoretical basis for the treatment of heavy metal pollution in the waste land of Changhua lead zinc mine and its surrounding soil. Through the field investigation of Hainan Changhua lead-zinc mine waste and the surrounding soil, and collected 56 soil samples of the waste, heavy metal content of soils were determined, the heavy metal content of the study area were analyzed by using statistical methods, statistical law reveals the study of heavy metal pollution in the region; use of environmental quality, the method of single factor pollution index Nemerow index, geoaccumulation index and potential ecological risk index of Hainan Changhua lead-zinc mine waste and the surrounding soil to analyze and evaluate the reasonable. The main conclusions are as follows: (1) Hainan Changhua lead-zinc mine waste and heavy metals in the soil around the Cr coefficient of variation was 52.76%, the lowest, the coefficient of variation was relatively small, which indicates that the distribution of Cr heavy metals is relatively uniform, the discrete degree is relatively low; and the dispersion degree of Cu, Cd, Pb is very high, distribution is not uniform; Ni, Zn and As dispersion degree is the highest, the most uneven distribution. The content of Cu, Zn, Cd and Pb of heavy metals is quite high. Are the soil background value of Hainan province 35.57, 52.66, 363.40, 144.25 times, the content ratio of CdPbZnCu; the average content of Ni was slightly higher than the background values of Hainan, the average content of Cr and As were significantly lower than the soil background values of Hainan Province, but the biggest value was more than the Hainan soil background value. (2) heavy metals Cu-Pb and Zn-Cd are highly correlated, and their correlation coefficients are over 0.9. The possibility of coming from the same source is very large, which is due to the development of lead-zinc mineral resources. The correlation between Cr, As and various heavy metal elements were not high, but Cr and As have a certain correlation; principal component analysis showed that the three components in the highest load of heavy metal elements between each other are showing a high degree of correlation, showing their pollution are from the same factors. Cluster analysis shows that Zn-Cd is a class, Pb-Cu is a class, and Ni-As-Cr is also a class. (3) the semi variogram model of heavy metal content showed that the semi variance function of As and Cr was spherical model, while the semi variogram model of heavy metals Cu, Ni, Pb and Zn was Gauss's model. Only the semivariogram model of heavy metal Cd was exponential model. Heavy metals in the study area showed strong spatial correlation, and most of the spatial variability was caused by structural factors such as soil matrix, climate and terrain. Heavy metal elements in regions with higher As content for the reclamation area and tailing area; the highest value of Cd and Zn in the three position, respectively, the eastern tailing area service area and river bend area; Pb and Cu were the highest on both sides of the bridge, service area, residents around the point, and extends to the Eastern District of tailings the whole northwest large area and reclamation area; heavy metal element Cr mainly distributed in the northwest of tailings and waste rock field, surrounding the service area and the surrounding rivers of southwest end of Ni in the study area showed a scattered distribution, and at the same time, the content of two kinds of heavy metals were lower than the national standard soil quality standard level three. (4) single factor pollution index evaluation results show that according to the national soil quality standard three level standard, the heavy metal Cd in the study area is almost all serious pollution level, Cu pollution is lighter, there is slight pollution only around the bridge and along the road to the south. The heavy metals of Pb and Zn in the research area of the Northeast are clean area, the contaminated area of the severity of Pb for the northern region, the tailings reclamation area surrounding and extending to the northwest region, serious level of heavy metal Zn pollution is mainly concentrated in the service area, bridge and left, Eastern, Northern District tailings reclamation area and river bend and extending to the northwest; comprehensive pollution evaluation results show that Nemero Nemero, the comprehensive pollution index of heavy metals of Cu is 1.48, belonging to slight pollution level, while Zn, Cd and Pb of the Nemero pollution index were 16.69, 61.46 and 23.33 were severe pollution levels; cumulative pollution index evaluation results showed that the pollution of Cd the extent of the most serious, very serious pollution level, followed by Pb, all at a very basic level of serious pollution, heavy metals of Cu and Zn in the study of regional pollution is relatively light; 7 Heavy metal potential ecological risk degree is in the order of CdPbZnCuAsNiCr, the potential ecological risk index of heavy metals in the value of Cd is 363.370, the degree of pollution reached a serious level, the potential ecological risk index of heavy metals of Pb is 123.317, belongs to the risk of contamination degree of heavy elements, other potential risk index were lower than 40, a slight pollution risk degree, comprehensive the potential ecological risk index reached 514.596, the degree of pollution is severe, for the local ecological risk is high. Among them, the contribution rate of Cd was the largest, reaching 70.62%.
【学位授予单位】：海南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X753;X825;X53

【相似文献】