陕北能源化工基地土壤中重金属与多环芳烃污染现状及其污染风险分析

发布时间：2018-07-17 09:06

【摘要】：为了了解陕北能源化工基地土壤中重金属以及多环芳烃的污染现状,本研究在榆林市矿区范围内选取了38个土壤采样点,分别检测分析了其中8种重金属(As、Cr、Cd、Cu、Hg、Pb、Mn、Zn)和16种多环芳烃(Nap、Acpy、Acp、Flu、Phe、Ant、Flt、Pyr、Ba A、Chr、Bbf、Bkf、Bap、Ind、Dba、Bghip)的污染情况,并进行了相关的污染风险分析。为城市土壤污染管理和环境保护与修复提供了依据,研究结果如下:(1)榆林市矿区范围内的土壤均不同程度受到8种重金属污染,重金属的含量在0.11~4850μg/g之间,从一定程度上可以说明,榆林市地区土壤重金属污染较严重,其中Cd,Hg,Cu污染最为严重。重金属污染的主要原因是由于矿山的过度开采,固体废弃物的随意堆积以及大气的沉降作用、污水灌溉等造成。(2)对重金属元素间的相关性进行了分析,结果发现:Cr-Cu,Cu-Cd,Cd-Pb,Cd-Hg,Pb-Hg,Cr-Mn具有良好的相关性,相关系数分别是0.545,0.522,0.883,0.565,0.628,0.619。可以看出,Cd-Pb相关性最高,说明土壤中的Cd和Pb元素可能具有相同的来源,经过沉淀和吸附累积在土壤中,其他重金属元素间相关关系不高,说明土壤中重金属污染属于混合来源。(3)分别运用内梅罗污染指数法和地累积指数法对8种重金属的污染风险进行了分析,结果表明:采用内梅罗污染指数法得到取样点S22污染指数最高,平均值为173.55,超出重度污染最低值50倍以上;采用地累积指数法得出38个采样点中有25个点均达到中度污染,其中有四个点的污染指数属于强污染级别,应引起足够重视。(4)对能源化工基地土壤样品中的多环芳烃污染情况进行分析,结果发现:土壤中16种PAHs总浓度在2.6-864.2μg/kg之间,平均值为94.5μg/kg,PAHs含量最高的两个点分别是S22和S18,样品中的含量分别为190.8μg/kg和188.2μg/kg。(5)计算了榆林市矿区土壤中PAHs对儿童和成年不同暴露途径下的终生致癌风险ILCRs(probabilistic incremental lifetime cancer risk),其中由于呼吸作用产生的ILCRs相对其它两种暴露途径下的ILCRs很小,从总ILCRs来看,矿区土壤中PAHs对人体健康影响程度的大小从高到低依次为:成年女性成年男性女孩男孩。
[Abstract]:In order to understand the pollution status of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in soil of energy and chemical industry base in Northern Shaanxi, 38 soil sampling sites were selected in Yulin mining area. The pollution of 8 kinds of heavy metals (As-CrCrCrCrcdcdCuHgPbPbMn-Zn) and 16 kinds of Nap-Acpy-AcpPhe-FluPhea (AntPhea) were detected and analyzed respectively, and the pollution risk analysis was carried out on the basis of the analysis of the pollution risk of Indba Bghip (Indba Bghip). The results are as follows: (1) the soils in Yulin mining area are polluted by 8 kinds of heavy metals to varying degrees, and the content of heavy metals is 0.114850 渭 g / g. To some extent, it can be concluded that the pollution of heavy metals in the soil of Yulin City is more serious, among which the pollution of CD HgCU is the most serious. The main causes of heavy metal pollution are the overmining of mines, the random accumulation of solid wastes, the sedimentation of the atmosphere, the sewage irrigation and so on. (2) the correlation between heavy metal elements is analyzed. The results show that there is a good correlation between the Cd-PbCd-PbCd-Pb-HgCn-Mn and the correlation coefficients of 0.545and 0.5220.883U 0.5650.683C ~ (0.628) ~ 0.619, respectively. It can be seen that Cd-Pb has the highest correlation, indicating that CD and Pb in soil may have the same source, and the correlation between other heavy metal elements is not high after precipitation and adsorption accumulation in soil. The results show that heavy metal pollution in soil belongs to mixed source. (3) the pollution risk of eight heavy metals was analyzed by using Nemero pollution index method and ground accumulation index method, respectively. The results showed that the sampling point S22 pollution index was the highest with the mean value of 173.55, which exceeded the lowest value of severe pollution by 50 times, and 25 of the 38 sampling points were moderately polluted by the method of ground accumulation index. The pollution index of four points belongs to the strong pollution grade, which should be paid enough attention to. (4) the PAHs in the soil samples of the energy and chemical industry base were analyzed. The results showed that the total concentrations of 16 PAHs in the soil ranged from 2.6-864.2 渭 g/kg. The average value of PAHs was 94. 5 渭 g / kg PAHs and S22 and S18, respectively. The contents of PAHs in the samples were 190.8 渭 g/kg and 188.2 渭 g / kg. respectively. (5) the lifetime carcinogenic risk ILCRs (probabilistic incremental lifetime cancer risk), of children and adults exposed to PAHs in the soils of Yulin mining area were calculated. The ILCRs produced by respiration are smaller than those of the other two exposure pathways. According to the total ILCRs, the effect of PAHs on human health in the soil of the mining area was from high to low: adult female, adult male, male and male.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X825

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