能源型工业园区土壤重金属污染分布特征及评价

发布时间：2018-03-30 21:39

本文选题：工业园区　切入点：土壤重金属　出处：《中北大学》2017年硕士论文

【摘要】：本文以山西省朔州市某能源型工业园区为研究对象,采集了工业园区表层土壤样品56个和亚表层土壤样品56个,测定了表层和亚表层土壤的pH、有机质、水分以及7种重金属元素Cu、Zn、Pb、Cd、As、Hg、Cr的含量,并对表层土壤样品的7种重金属元素进行了形态特征分析。结果表明:(1)土壤pH的变异系数处于弱程度的变异,表明研究区土壤pH值受人为因素影响小;土壤有机质、水分、重金属元素的变异系数处于中等程度的变异,表明它们受人为活动的影响较大,其中元素Hg受人类活动的影响比较明显。表层土壤重金属Cu、Zn、Pb、Cd、As、Hg、Cr的含量均值都超过了山西省土壤背景值,并且重金属含量随着土壤深度的加深而减小。(2)运用地统计学中的克里金插值分析表层和亚表层土壤重金属含量的空间分布特征,工业园区重金属元素Cu、Zn、Pb、Cd、As、Hg、Cr的高含量都分布在冶金厂的周边。重金属元素Cu、Zn、Cd、As、Hg、Cr污染严重的场地为冶金厂、电厂,而重金属元素Pb污染严重的场地为冶金厂、水泥厂。(3)采用单因子指数法、内梅罗综合污染指数、潜在生态危害指数法评价土壤环境质量得出Hg元素污染最为严重,工业园区的整体土壤状况达到轻微的生态风险。基于人体健康风险评估得出:采样点电厂、洗煤厂、冶金厂、水泥厂、居民区、办公楼的综合致癌风险值均超过可接受值10-6;采样点冶金厂、居民区、办公楼的综合危害指数超过可接受值1。重金属的致癌风险、非致癌风险贡献率大小顺序分别为CrAsCd、AsCrCdHg。(4)表层土壤元素Cu、Zn、Pb、As、Hg、Cr在采样点工业园区、电厂、洗煤厂、冶金厂、水泥厂、居民区、办公楼存在的形态都是以残渣态为主,在碱性土壤环境下吸附增强,土壤胶体对重金属的吸附量增加,生物有效性差,故存在的形态以残渣态为主;而Cd在碱性土壤环境下主要以碳酸盐和氧化物结合态为主,故研究区域Cd主要以弱酸提取态和可还原态存在。风险评价编码法评估结果表明,各采样点的重金属元素Cd的评估结果均为高风险,应该予以重点关注。
[Abstract]:In this paper, 56 surface soil samples and 56 subsurface soil samples were collected from an energy type industrial park in Shuozhou City, Shanxi Province. The pH and organic matter of surface and subsurface soils were determined. Water content and the content of 7 heavy metal elements, Cuznznznzhupercr, and the morphological characteristics of 7 heavy metal elements in surface soil samples were analyzed. The results showed that the variation coefficient of soil pH was weak, and the variation coefficient of soil pH was in a weak degree, the results showed that the variation coefficient of soil pH was in a weak degree. The variation coefficients of soil organic matter, water and heavy metal elements are in medium degree, indicating that they are influenced by human activities. Among them, the element Hg is obviously affected by human activities. The mean value of the heavy metal Cu ~ (2 +) ZnPb ~ (2 +) CD ~ (2 +) ~ (2 +) ~ (2 +) HgN ~ (Cr) is higher than the soil background value of Shanxi Province. And the heavy metal content decreases with the deepening of soil depth. (2) using Kriging interpolation in geostatistics to analyze the spatial distribution characteristics of heavy metal content in topsoil and subsurface soil. The high content of heavy metal elements, CuOZZZZZN, CDB, CDSU, HgCU, is distributed in the periphery of metallurgical plants. The sites where the heavy metal elements are seriously polluted are metallurgical plants and power plants, while the sites where heavy metal elements are seriously polluted are metallurgical plants, while heavy metal elements such as Pb are seriously polluted in metallurgical plants, and the sites where heavy metal elements are seriously polluted are metallurgical plants. The single factor index method, the Nemero comprehensive pollution index and the potential ecological hazard index method were used to evaluate the soil environmental quality. The results showed that Hg pollution was the most serious. The overall soil condition of the industrial park has reached a slight ecological risk. Based on the human health risk assessment, the following results are obtained: sample point power plants, coal washing plants, metallurgical plants, cement plants, residential areas, The comprehensive carcinogenic risk values of office buildings exceed the acceptable value of 10-6; the comprehensive hazard index of metallurgical plants, residential areas and office buildings in sample sites exceeds the acceptable value 1.The carcinogenic risk of heavy metals, The order of the non-carcinogenic risk contribution rate is CrAsCdCU AsCrCdHg.Hg.Hg. 4) the surface soil element CuOZnZnPbPbPbAsHG / Cr in the sample site industrial park, power plant, coal washing plant, metallurgical plant, cement plant, residential area and office building are all in the form of residue. In alkaline soil, the adsorption of heavy metals increased and the bioavailability of soil colloids increased, so the forms of CD in alkaline soil were mainly residual state, while in alkaline soil environment, carbonate and oxide bound forms were the main forms of CD, while in alkaline soil, the adsorbed amount of heavy metals increased and the bioavailability was poor. Therefore, CD in the study area mainly exists in the form of weak acid extraction and reducible state. The results of risk evaluation and coding method show that the evaluation results of heavy metal elements CD in each sampling point are all high risk and should be paid more attention to.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;X825

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