变化生境下土壤—底泥POPs柱状分层比较研究

发布时间：2018-03-25 10:24

本文选题：采煤沉陷区　切入点：持续性有机污染物　出处：《安徽理工大学》2017年硕士论文

【摘要】：持久性有机污染物(POPs)大部分具有生物毒性、迁移性、蓄积性、持久性及"三致"(致癌、致畸、致突变)效应等特点,其广泛存在于环境介质中,对人类和生态环境构成巨大的危害,目前POPs成为了全球性重点控制的污染物。本研究利用气相色谱-质谱(GC-MS)方法,选取变化生境下即最开始的陆生环境逐渐演变为水生环境的淮南矿区中杨庄、谢桥两个典型沉陷区为研究区域,以采煤沉陷前的土壤和沉陷后水体底泥中14种多氯联苯和美国环保署(EPA)优先控制的16种多环芳烃为研究对象,对变化生境下土壤-底泥中柱状不同层位POPs横纵向分布特征、空间分布特征、物质组成特征、污染来源及影响因素等规律进行了系统地比较研究,并对POPs污染现状进行了分析,旨在了解典型POPs污染特征及潜在风险。主要研究结果及结论如下:通过建立一套成熟的前处理、提取与净化方法,对变化生境下沉陷区土壤-底泥中POPs采用GC-MS方法进行定性和定量检测分析,实验整个过程进行了质量控制与保证,检测方法具有较高的回收率,符合EPA等环境分析的要求。变化生境下除杨庄沉陷区土壤PCB105、PCB153、PCB180三种单体未检出外,其余PCB单体全部检出,16种PAHs物质在沉陷区的检出率为100%。通过对变化生境下不同沉陷区土壤-底泥中不同层位PCBs和PAHs检测结果进行统计分析。杨庄不同层位土壤ΣPCBs浓度在1.052-19.252 ng/gdw,不同层位底泥ΣPCBs浓度在1.024-62.514 ng/g;谢桥不同层位土壤ΣPCBs浓度在1.244-27.774 ng/g,不同层位底泥ΣPCBs浓度在0.239-12.622 ng/g。杨庄不同层位土壤ΣPAHs浓度在42.113-22149.023 ng/g,不同层位底泥ΣPAHs浓度在43.968-7644.210 ng/g;谢桥不同层位土壤ΣPAHs 浓度在 17.809-1617.749 ng/g,不同层位底泥∑PAHs浓度在35.673-264.553 ng/g。通过与其他地区污染调查的对比,发现沉陷区土壤-底泥PCBs、PAHs浓度处于中等偏低水平。对于杨庄沉陷区土壤和底泥受影响比谢桥沉陷区相对较大。杨庄沉陷区水体因受到外界补给及人为干扰较大,沉陷区底泥中PCBs、PAHs污染程度大于土壤。通过变化生境下不同沉陷区土壤-底泥中柱状PCBs、PAHs的箱式图和Arcgis空间插值图,对污染物垂向和空间特征进行对比分析。杨庄采煤沉陷区底泥中不同层位PCBs浓度明显高于土壤,而土壤中PCBs含量垂向变化更稳定,泥河河床上的西南方点位PCBs浓度偏高,土壤西南方采样点位受煤矸石影响也相对偏高;谢桥沉陷区土壤中PCBs浓度高于底泥,而底泥中PCBs含量垂向变化更稳定,谢桥沉陷区西边PCBs浓度偏大。对于PAHs来说,杨庄沉陷区除5-10cm层外底泥中PAHs略高于土壤,而土壤中PAHs垂向变化更稳定;谢桥采煤沉陷区土壤中PAHs浓度略高于底泥,而底泥中PAHs垂向变化更稳定,西边沉陷底泥中PAHs浓度高于东边,PAHs浓度从交通要道附近水域向东西两边减少。通过变化生境下不同沉陷区土壤-底泥中不同层位PCBs、PAHs的物质组成百分比图、三相图、单体柱状分布图,对污染物组成特征进行对比分析;同时结合比值法初步判断可能的污染来源。杨庄采煤沉陷区土壤和底泥主要是以三氯联苯、四氯联苯、五氯联苯等低氯联苯为主,底泥与土壤呈现类似特征;谢桥沉陷区土壤污染以低氯联苯为主,PCBs来源于长距离迁移,底泥中三至六氯联苯均有一定的检出率,呈现混合污染。对于PAHs物质,杨庄沉陷区土壤-底泥呈现以中低环物质为主,3环芳烃的主要贡献物质为Phe和F1,为石油源,4环芳烃主要物质为Chr、Flu、Pyr,来源于煤的燃烧,PAHs呈现混合污染来源;谢桥土壤-底泥中PAHs主要以3环芳烃为主,其次是4环芳烃,也呈现混合污染来源。通过变化生境下不同沉陷区土壤-底泥中不同层位PCBs、PAHs与理化指标的拟合曲线以及进行相关性分析,对比可发现:有机质与PCBs、PAHs相关性很强,底泥中PCBs、PAHs与其拟合系数高于土壤,拟合系数大小由表层垂向增加后递减;有机质与三氯联苯、四氯联苯等低氯联苯相关性较大,与PAHs大部分同系物在0.01水平上显著相关。而对于粒径来说,其与土壤-底泥不同层位PAHs、PCBs拟合系数普遍偏小,说明介质不同层位粒径分布不会影响到PAHs、PCBs的分布情况。综上所述,本研究从变化生境下采煤沉陷区土壤-底泥POPs柱状分层进行比较,对进一步掌握POPs在介质中的迁移特性及沉陷区生态健康具有重要作用。
[Abstract]:Persistent organic pollutants (POPs) has the most biological toxicity, migration, accumulation, persistence and the "three letter" (carcinogenic, teratogenic, mutagenic effect) and other characteristics, it is widely present in the environment medium, a great harm to human and ecological environment at present, POPs has become a global focus on the control of pollutants. Chromatography-mass spectrometry this study using gas (GC-MS) method, the changes of habitat selection, the terrestrial environment began to gradually evolve into the aquatic environment in Huainan mining area, two typical Xieqiao subsidence area as the study area, with 14 kinds of PCBs of coal mining subsidence and subsidence of the soil before and after water sediment the United States Environmental Protection Agency (EPA) of 16 polycyclic aromatic hydrocarbons priority control as the research object, the changes of soil habitats in the sediment column in different layers of POPs horizontal and vertical distribution characteristics, spatial distribution characteristics, composition characteristics of substances, pollution sources and impact factors The law makes a systematic comparative study, and the status of POPs pollution were analyzed, aimed to understand the pollution characteristics and potential risk of typical POPs. The main results and conclusions are as follows: through the establishment of a mature pretreatment, extraction and purification methods, changes in habitat soil and sediment subsidence POPs by GC-MS method the qualitative and quantitative analysis, the whole process of quality control and assurance, recovery detection method has higher rate, consistent with analysis of EPA environment. Changes in habitats except Yang soil PCB105, PCB153, PCB180 three kinds of monomers were not detected, the rest of the PCB monomer detected in all, 16 kinds of PAHs material in the subsidence area detection rate of 100%. according to the change of different habitats in different layers of PCBs and PAHs subsidence of soil and sediment detection results were analyzed statistically. Yang in different soil layers at the level of 1 sigma PCBs 52-19.252 ng/gdw, different layers of sediment total PCBs concentration in 1.024-62.514 ng/g; Xie bridge in different soil layers PCBs concentration in 1.244-27.774 ng/g, different layers of sediment concentration in the 0.239-12.622 ng/g. PCBs, total PAHs concentration in different soil layers in 42.113-22149.023 ng/g, different layers of sediment concentration in the 43.968-7644.210 Sigma PAHs ng/g; Xieqiao total PAHs concentration in different soil layers 17.809-1617.749 ng/g, compared with other regions through the investigation of pollution in different layers of sediment total PAHs concentration in 35.673-264.553 ng/g., found in soil and sediment PCBs, PAHs concentration in the medium low level. For Yangzhuang subsidence area soil and sediment affected than in Xieqiao subsidence area is relatively large. Yang subsidence due to the external water supply and human noise, PCBs area subsidence sediment, the pollution degree of PAHs was greater than that of soil. With the change of subsidence area soil under different habitats Column PCBs soil sediment, PAHs type map and Arcgis spatial interpolation map, comparative analysis of pollutants to the vertical and spatial characteristics in different layers of sediment. The concentration of PCBs was significantly higher than that of soil in Yangzhuang coal mining subsidence, and vertical soil PCBs content changes to the more stable, mud river bed of the South West Point PCBs the high concentration of soil sampling points by the South West coal gangue is relatively high; Xie Qiao PCBs concentration in soil was higher than that of subsidence and vertical sediment PCBs content in sediment to change more stable, Xieqiao subsidence area west of the concentration of PCBs is too large. For PAHs, Yang Zhuang subsidence area in addition to 5-10cm PAHs in the sediment layer slightly higher than the soil, and the soil PAHs vertical variation is more stable; soil PAHs concentration is higher than that of sediment in Xieqiao coal mining subsidence, and sediment in the vertical variation of PAHs is more stable, the subsidence of PAHs concentrations in sediment were higher than the East, the concentration of PAHs from traffic arteries The waters near to the East and west sides of reduced. Through the change of habitat under different soil and sediment in different layers of PCBs, the percentage of PAHs material composition diagram, phase diagram, single column shaped distribution of pollutant composition characteristics were analyzed; at the same time ratio method combined with the preliminary judgment of potential pollution sources. Yangzhuang Coal Mining Subsidence Area Soil and sediment mainly three PCBs, four chloro biphenyl, five chloro biphenyl low PCBs, sediment and soil showed similar characteristics; Xieqiao subsidence of soil pollution with low chlorine biphenyl, PCBs from long distance migration, the detection rate of three and hexachlorobiphenyl had some sediment, showing mixed pollution for PAHs. The material, Yangzhuang Subsidence Area Soil Sludge in the low ring material, the main contribution material 3 aromatic hydrocarbons were Phe and F1, for the oil source, 4 aromatic main material for Chr, Flu, Pyr, derived from coal combustion, PA Hs presents the mixed pollution sources; Xie Qiao soil PAHs in the sediment mainly in the 3 aromatic ring, followed by 4 aromatic ring, also presents the mixed pollution sources. By changing the habitat under different soil and sediment in different layers of PCBs, PAHs and physicochemical index curve fitting and correlation analysis, comparison found that the organic matter and PCBs, PAHs is a strong correlation between PAHs, PCBs in the sediment, and the fitting coefficient is higher than that of soil, the fitting coefficient decreased from the surface of the vertical size increases; organic matter and three PCBs, four chloro biphenyl PCBs correlated with low, most of the PAHs homologues in 0.01 level was significantly correlated to. The particle size, the different soil and sediment layers PAHs, PCBs fitting coefficient is generally small, medium size distribution in different layers that will not affect the PAHs particle, the distribution of PCBs. In summary, this study from the coal mining subsidence area change of habitats The comparison of soil and sediment POPs columnar stratification plays an important role in the further understanding of the migration characteristics of POPs in the medium and the ecological health of the subsidence area.

【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592

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