济南市湿沉降中砷、镉、铬、镍、铅的污染特征及其对斑马鱼生物毒性的研究

发布时间：2018-06-22 22:35

本文选题：大气湿沉降 + 重金属　；参考：《山东大学》2017年硕士论文

【摘要】：近年来,随着我国经济的发展,工农业生产规模日益扩大、城市人口日渐密集、机动车辆逐渐增多,导致重金属向环境中的排放量不断增加,大气重金属污染已然成为一个不容忽视的环境问题。存在于大气中的重金属危害巨大,不仅污染大气环境,而且会通过大气沉降作用进入地表环境污染水体及土壤,从而威胁到人类健康。湿沉降在重金属的环境迁移过程中起着重要的作用,因此本文对济南市大气湿沉降中重金属砷、镉、铬、镍、铅的污染情况进行分析评价,并以湿沉降中五种重金属的环境浓度为基础选取斑马鱼为受试生物,研究其对斑马鱼的生物毒性。本研究在实验过程中使用自主研发的湿沉降自动采集装置对济南市2015年9月至2016年8月间的湿沉降进行采集。通过对济南市大气湿沉降中砷、镉、铬、镍、铅污染特征的分析,结果表明济南市湿沉降中五种重金属的平均浓度具有明显的季节变化特征且趋势相似,整体表现为冬春季高于夏秋季,其中冬季最高。五种重金属中Pb的季节及年沉降通量最高,接下来依次是Ni、Cr、As、Cd,而且夏季湿沉降通量明显高于其他季节。降水量以及湿沉降pH值对重金属浓度的影响均呈现负相关性。根据相关性分析、主成分分析和聚类分析的结果可以将济南市湿沉降中五种重金属按其来源的相似性大致分为三组,Cd和Pb可能主要来源于城市交通;Cr和Ni可能主要来源于工业活动;As主要来源于燃煤。与相关标准进行对比得出济南市湿沉降中五种重金属浓度均低于地表水II类标准,除铅略高于生活饮用水卫生标准外,其余均低于该标准。通过潜在生态危害指数法对济南市湿沉降中As、Cd、Cr、Pb进行生态危害评价,四种重金属在四个季节的潜在生态危害指数为冬季春季秋季夏季,总的潜在生态风险水平处于轻微风险状态。此外以研究期间各重金属单次最高浓度为基础,对斑马鱼进行单一及复合毒性试验,研究结果表明复合暴露明显提升了重金属对斑马鱼的毒性效应,其中镉在复合暴露引起的行为学毒性中起到主要作用,并且重金属对斑马鱼毒性呈明显的时间-效应、浓度-效应关系。单一暴露时,As和Cr对斑马鱼的致死率较低,运动速度与对照组无显著性差异;Cd、Ni和Pb在高浓度时斑马鱼死亡率明显上升,对游动速度呈明显抑制作用。复合暴露浓度为环境浓度的6倍时显著降低仔鱼运动速度;10倍时在暴露6d后对斑马鱼死亡率出现较显著的影响并且显著抑制仔鱼的运动速度;100倍和1000倍暴露时个体全部死亡。通过各种金属环境浓度的单一暴露与复合暴露结果可以看出,环境浓度下并没有对斑马鱼产生显著的生物毒性,但当暴露浓度提升至环境浓度的6倍时显著地降低了仔鱼的游动速度。由于重金属具有生物富集性,因此济南市大气湿沉降中砷、镉、铬、镍、铅五种重金属仍然对水体环境安全性及人体健康存在潜在危害。
[Abstract]:In recent years, with the development of China's economy, the scale of industrial and agricultural production is increasing, urban population is becoming denser and the number of motor vehicles is increasing, which leads to the increasing emission of heavy metals to the environment. Heavy metal pollution in the atmosphere has become an environmental problem that can not be ignored. Air environment, and through atmospheric sedimentation, enters the surface environment to pollute the water and soil, which threatens human health. Wet settlement plays an important role in the environmental migration of heavy metals. Therefore, the pollution of heavy metals, as, cadmium, chromium, nickel and lead, in the air wet settlement of Ji'nan City, is analyzed and evaluated, and the wet settlement is made. The biological toxicity of zebrafish to zebrafish was studied based on the environmental concentration of the five kinds of heavy metals. In this study, the wet settlement of Ji'nan city from September 2015 to August 2016 was collected by the self developed wet settling automatic collection device, and through the arsenic, cadmium and chromium in the air wet settlement of Ji'nan. The analysis of the characteristics of nickel and lead pollution shows that the average concentration of five heavy metals in the wet settlement of Ji'nan has obvious seasonal variation characteristics and the trend is similar. The overall performance is that winter and spring are higher than summer and autumn, which is the highest in winter. The season and annual settlement flux of Pb in five kinds of heavy metals is the highest, followed by Ni, Cr, As, Cd, and summer wet. The settlement flux is obviously higher than that of other seasons. The effect of precipitation and pH on the concentration of heavy metals has a negative correlation. According to the correlation analysis, the results of principal component analysis and cluster analysis can be divided into three groups according to the similarity of the five heavy metals in the wet settlement of Ji'nan, and Cd and Pb may be mainly from the city. Traffic; Cr and Ni may mainly come from industrial activities; As mainly comes from coal burning. Compared with the related standards, the five heavy metals in the wet settlement of Ji'nan are lower than the II standard of surface water, and the other is lower than the standard of drinking water. The other is lower than the standard. The potential ecological hazard index method is used to sink the Ji'nan city. The ecological hazard assessment was carried out in As, Cd, Cr, and Pb. The potential ecological hazard index of four heavy metals in the four seasons was in winter spring autumn and summer, and the total potential ecological risk level was in a mild risk state. The results showed that compound exposure significantly enhanced the toxic effects of heavy metals on zebrafish, and cadmium played a major role in the behavioral toxicity of compound exposure, and the toxicity of heavy metals to zebrafish showed a significant time effect, concentration effect relationship. When single exposure, the mortality rate of As and Cr to zebrafish was lower, movement speed and control There was no significant difference in the group of Cd, Ni and Pb. The mortality of zebrafish increased significantly at high concentration, and obviously inhibited the speed of swimming. At the 6 times of the environmental concentration, the compound exposure concentration significantly reduced the speed of the fish movement; at the time of 10 times the exposure to 6D, the mortality of zebrafish was significantly affected and the speed of the larvae was significantly inhibited; 100 The single exposure and compound exposure of various metal environmental concentrations showed that the environmental concentration did not produce significant biological toxicity to zebrafish, but the swimming speed of the larvae was significantly reduced when the exposure concentration was raised to 6 times of the environmental concentration. As heavy metals were produced by heavy metals. Therefore, five heavy metals, such as arsenic, cadmium, chromium, nickel and lead, still have potential hazards to water environmental safety and human health in Ji'nan's atmospheric wet deposition.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X51;X171.5

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