泰州市空气重金属污染的藓类监测

发布时间：2018-06-02 19:46

本文选题：重金属污染 + 生物指示　；参考：《南京林业大学》2014年硕士论文

【摘要】：藓类植物是公认的大气污染指示物，其植物体较小，角质层不发达，具假根但不能汲取养料，相对体表面积较大，阳离子交换能力强，能吸收溶解于其体表水中的矿质元素，使得其生长生理摆脱了基质的干扰。因此，藓类是比较理想的空气重金属污染监测植物材料。本实验选择泰州地区常见的细叶小羽藓（Haplocladium microphyllum）为实验材料，用网格布点法（10km×10km，共60个样方），采集细叶小羽藓样品，经分离、洗净、烘干、磨碎、过筛、消煮等处理后，ICP-AES测定Cd、Cr、Cu、Ni、Pb、Zn、Hg等7种重金属元素的含量，利用ArcGIS软件绘制各重金属元素的空间分布图，分析泰州市各地区大气重金属沉降与污染情况，并评估其潜在生态危害程度。此外，本研究还利用白齿泥炭藓（Sphagnum girgensohnii）制成藓袋，结合道路灰尘对泰州市区近地面空气中As、Cd、Cr、Cu、Mn、Pb、V、Zn等8种重金属污染物的含量与污染特征分析，评估市区主要公共场所的重金属污染潜在生态危害程度。主要研究结果如下： 1-1.重金属含量分析表明，细叶小羽藓体内Zn＞Cu＞Pb＞Cr＞Ni＞Cd＞Hg，其中，对Cd、Cu、Pb、Zn的富集能力相对较强，对Cr、Ni、Hg富集能力较弱。其中对Cd的富集能力最强，为土壤中Cd元素的2.5倍，最大可达1096.25mg·kg-1；对Hg的富集能力最弱，，为土壤含量的0.636倍，最大值仅为0.79mg·kg-1。 1-2.对小羽藓体内各重金属元素含量的相关性分析表明，Cd、Cu、Pb、Zn之间均具有极显著正相关性，这可能与这几种元素本身污染协同性较强的性质有关，也可能它们面临着共同的污染源。主因子分析表明，Cd、Cu、Pb和Zn受人为活动影响较大，是典型的人为污染源；Cr和Ni主要来自土壤，属于自然源。 1-3.重金属污染因子分析结果表明，泰州市大气中Cd污染较为严重，Cr和Ni污染最轻，污染程度：Cd＞Zn＞Cu＞Pb≈Hg＞Ni＞Cr。重金属潜在生态风险评价表明，泰州市各地区均存在较高的潜在生态风险：Cd＞Hg＞Cu＞Pb＞Ni＞Zn＞Cr，其中Cd和Hg是主要污染因子，两者的污染贡献率之和达到90%左右。 1-4.结合泰州市具体的地理空间环境与经济发展情况分析表明，位于泰州北部的兴化市，区域经济发展主要以观光农业与水产养殖为主，大气环境最好，污染最轻；而位于泰州最南端的靖江市，则相对污染较为严重，该市紧邻长江，机电制造与港口船舶是其主要经济支柱。 2-1.泰州市城区重金属污染较为严重，藓袋中Cd、Zn和Pb3种重金属的平均含量分别达到了土壤背景值的8.41、6.94和5.85倍；道路灰尘中Zn、Cd、Pb和Cu的平均含量则达到了背景值的22.63、6.58、5.13和4.45倍。 2-2.相关性分析表明，主要重金属污染物之间表现出显著的正相关性。其中，藓袋重金属含量比土壤灰尘中的含量低，近地面空气中的重金属污染来源相对单一。 2-3.重金属污染潜在生态危害评价结果表明，Cd是泰州市区近地面空气与道路灰尘重金属潜在生态风险偏高的主要因子，其生态危害贡献率分别达到了92.43%和72.46%。汽车尾气是泰州市城区重金属污染的主要来源，客运车站是重金属潜在生态风险最高的地区。
[Abstract]:Mosses are generally recognized as an indicator of atmospheric pollution, with smaller plants and underdeveloped cuticles, with a root but unable to absorb nutrients, relatively large surface area, strong cation exchange capacity and can absorb mineral elements dissolved in its surface water, making the growth physiology free from matrix interference. Therefore mosses are ideal air. Heavy metal pollution monitoring plant materials. This experiment selected the common Haplocladium microphyllum of Taizhou area as experimental material, using grid cloth point method (10km x 10km, total 60 samples) to collect samples of fine leaf moss. After separation, washing, drying, grinding, sifting and boiling, ICP-AES was used to determine Cd, Cr, Cu, Ni, Pb, Zn, Hg and other 7 kinds. The content of heavy metal elements, using the ArcGIS software to draw the spatial distribution of the heavy metal elements, analysis of the atmospheric heavy metal settlement and pollution in Taizhou, and evaluate its potential ecological damage. In addition, this study also made use of Sphagnum girgensohnii to make moss bags, combined with road dust near the urban area of Taizhou city. Analysis of the content and pollution characteristics of 8 heavy metal pollutants such as As, Cd, Cr, Cu, Mn, Pb, V, Zn and so on in the air, and to evaluate the potential ecological hazards of heavy metal pollution in the main public places in the urban area. The main results are as follows:
The analysis of heavy metal content in 1-1. showed that the Zn > Cu > Pb > Cr > Ni > Cd > Hg in the moss. Among them, the enrichment ability was relatively strong for Cd, Cu, Pb. 0.636 times the amount, the maximum value is only 0.79mg. Kg-1.
The correlation analysis between 1-2. and the content of heavy metals in the moss showed that Cd, Cu, Pb and Zn had very significant positive correlation, which may be related to the strong synergism of these elements, and may also be faced with the common source of pollution. The main factor analysis showed that Cd, Cu, Pb and Zn were greatly influenced by human activities. Typical anthropogenic sources of pollution; Cr and Ni mainly come from soil and belong to natural sources.
The results of 1-3. heavy metal pollution factor analysis show that the pollution of Cd in Taizhou is more serious, and the pollution of Cr and Ni is the lightest, and the pollution degree is: Cd > Zn > Cu > Pb Hg > Ni > Cr. heavy metal risk assessment shows that there are high potential ecological risks in all regions of Taizhou. The contribution rate of the main pollution factors is 90%.
1-4. based on the analysis of the specific geographical space environment and economic development in Taizhou, it is shown that in Xinghua city in northern Taizhou, the main regional economic development is sightseeing agriculture and aquaculture, the atmospheric environment is the best and the pollution is the lightest, while the Jingjiang city in the southernmost end of Taizhou is relatively polluted, and the city is close to the Yangtze River and the electromechanical system. Shipbuilding and port ships are its main economic pillars.
2-1. the heavy metal pollution in the city of Taizhou is more serious. The average content of Cd, Zn and Pb3 in the bag of moss is 8.41,6.94 and 5.85 times of the soil background value, and the average content of Zn, Cd, Pb and Cu in road dust reaches the 22.63,6.58,5.13 and 4.45 times of the background value.
2-2. correlation analysis showed that the main heavy metal pollutants showed significant positive correlation. Among them, the content of heavy metals in the moss bag was lower than that in soil dust, and the pollution sources of heavy metals in the near ground air were relatively single.
The potential ecological hazard assessment results of 2-3. heavy metal pollution showed that Cd was the main factor of high potential ecological risk of heavy metals in Taizhou urban area and road dust. The contribution rate of ecological hazards reached 92.43% and 72.46%., respectively, and the automobile exhaust was the main source of heavy metal pollution in Taizhou City, and the passenger station was the potential heavy metal. The region with the highest ecological risk.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X831;X835

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