RCEES OpenIR  > 环境化学与生态毒理学国家重点实验室
Alternative TitleSource and Charateristics of Emerging Organic Pollutants
Thesis Advisor刘国瑞
Degree Grantor中国科学院生态环境研究中心
Place of Conferral北京
Degree Name理学硕士
Degree Discipline环境科学
Keyword环境持久性自由基( Epfrs 大气细颗粒物( Pm2.5 氯 代和 溴代多 环芳烃( Cl/br-pahs 分布特征 影响因素 environmentally Persistent Free Radicals (Epfrs), Atmospheric Fine Particulate Matter (Pm2.5), Chlorinated And Brominated Polycyclic Aromatic Hydrocarbons (Cl/br-pahs), Distribution Characteristics, Influencing Factors

      研究大气细颗粒物 PM2.5 的 成分对深入了解大气污染所导致的的健康效应至关重要 。环境持久性自由基( environmentally persistent free radicals , EPFRs是一种可以在 PM2.5表面稳定存在的新型有机污染物,其可以随大气细颗粒物迁移,并可以随 PM2.5一起进入生物体内 并发生转化 ,造成毒性反应。 目前对PM2.5中 EPFRs的研究还非常少 课题组前期已发现重雾霾天气下 PM2.5中有高 浓度的 EPFRs,本研究 对实际环境条件下 PM2.5中 EPFRs的 时间 分布特征、存在状态以及与多种环境因素之间的关系 进行 了深入 探讨 。
      我们采集了北京市 2018年 3月至 12月的 PM2.5样品,并使用电子顺磁共振技术( electron paramagnetic resonance EPR)对 PM2.5中的 自由基信号进行了检测,以研究 EPFRs的 时间 分布特征。并结合统计学分析的方法,探索温度、湿度等气象因素和 SO2、 NO2等污染物与 EPFRs的关系。 最后 ,多环芳烃不仅是 工业源 EPFRs的重要前驱物 也是 EPFRs环境转化的可能产物 我们也 研究 工业源及周边大气中 氯 /溴 代多环芳烃( Chlorinated and brominated polycyclic aromatic hydrocarbons Cl/Br-PAHs)的排放特征。 取得 的主要 结果如下:
      1. 北京市大气细颗粒物中 EPFRs主要为碳中心周围有杂原子的半醌类自由基, EPFRs在 PM2.5上的 平均浓度为 5.8×1021spins/g,平均大气浓度为 6.30×1017spins/m3。其分布具有明显的季节差异,主要 表 现为秋冬季节浓度高,春夏季节浓度低的特点, 而且 EPFRs的浓度分布呈现 右 偏的正态分布,主要表现为供暖期结束前后的 3月至 5月,空气中 EPFRs的浓度较高。 为进一步了解 PM2.5中 EPFRs的暴露风险, 本文还估算了 PM2.5中 EPFRs,通过呼吸作用的 日均吸入暴露风险,主要表现为男性对 PM2.5上 EPFRs的日暴露吸入量相当于每天吸入了 24根香烟焦油 EPFRs;女性对 PM2.5上 EPFRs的日暴露吸入量相当于每天吸入了 28根香烟焦油 EPFRs。
      2. 多重线性回归模型及 Pearson相关性分析发现,在秋冬季节 PM2.5、 NO2、O3和 CO的浓度,以及风速、降水量、温度和湿度是影响 EPFRs大气浓度的主要影响因素。 主要表现为, PM2.5、 NO2、 O3和 CO的浓度是空气中 EPFRs浓度的正贡献因素,而风速、降水量、温度和湿度是空气中EPFRs浓度的负贡献因素。在春夏季节,高温度、高湿度、高降水量和高 O3浓度的条件下,空气中 EPFRs的浓度明显降低。另外,本研究发现,污染物之间的相互作用影响空气中 EPFRs的浓度。
      3. 典型 工业源 铁矿石烧结 、 再生铝冶炼和再生铅冶炼过程 烟道气 中 19种 Cl-PAHs和 19 种 Br-PAHs的 平均浓度 分别为 68.3-156.3 ng Nm-3和 2.9-13.5 ng Nm-3。 三种金属冶炼过程 周 边 环境空气中 Cl-PAHs的浓度范围为 7.0-554pg m-3 Br-PAHs的浓度 范围为 3.0-126pg m-3。 周围空气样品和烟道气体排放之间 Cl/Br-PAHs同 类 物特征比较表明,冶金过程 Cl/Br-PAHs的排放在一定程度上影响了周 边 环境 Cl/Br-PAHs的污染水平 。 环境空气样品中 Cl-PAHs和 Br-PAHs的毒性当量TEQ)浓度分别为 0.03-3.61pg TEQ m-3和 0.001-0.23pg TEQ m-3 与二恶英 类的 TEQs相当 表明 Cl/Br-PAHs的 工业排放和环境风险不可低估 。铁矿石烧结 、再生 铝冶炼 和再生铅冶炼 排放的 Cl/Br-PAHs的同 类 物特征 与废弃物焚烧过程 明显不同 ,可 用作环境中 Cl/Br-PAHs溯源 的依据 。

Other Abstract

      The concentration and pollution characteristics of PM2.5, as well as the pollutants adsorbed on its surface, are the main causes of air pollution leading to human disease and death. Environmentally persistent free radicals (EPFRs) are a new type of organic pollutant that can exist stably on the surface of PM2.5. It can migrate with fine particles in the atmosphere and can enter the organism accompy with PM2.5, causing toxic reactions. At present, the research on EPFRs in atmospheric fine particles is also concentrated under laboratory conditions. Under the actual environmental conditions, the distribution characteristics, existence status of EPFRs in PM2.5 and the relationship with various environmental factors are still unclear.
      This study collected PM2.5 samples from March to December in Beijing, and used electron paramagnetic resonance (EPR) to detect free radical signals in atmospheric fine particles to study EPFRs in ambient air. Combined with statistical analysis methods, the connection between the atmospheric concentration of EPFRs and various environmental factors are explored. This study focuses on the relationship between meteorological factors and the concentration of air pollutants such as temperature, humidity, SO2, NO2 and atmospheric concentration of EPFRs. The emission characteristics and exposure levels of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs), which are precursors and reaction products of EPFRs, were studied. The relevant results are as follows:
      1. EPFRs in atmospheric fine particles in Beijing are mainly semiquinone radicals with heteroatoms around the carbon center. The average mass concentration of EPFRs in PM2.5 is 5.8×1021spins/g, and the average atmospheric concentration is 6.30×1017 spins/m3. The distribution has obvious seasonal differences, which are mainly characterized by high concentration in autumn and winter, low concentration in spring and summer, and the concentration distribution of EPFRs is right-normal distribution, expressed as the higher concentration of EPFRs in PM2.5 mainly from March to May before and after the end of heating period. To further understand the exposure risk of EPFRs in PM2.5, this paper also estimates the daily exposure risk of EPFRs in PM2.5 through the process of breath. The equivilant number of males inhaled of EPFRs on PM2.5 to cigarette tar EPFRs is 24 daily, and women's daily exposure to EPFRs on PM2.5 was equivalent to 28 cigarette tar EPFRs per day.
      2. Multiple linear regression model and Pearson correlation analysis found that the concentration of PM2.5, NO2, O3 and CO, as well as wind speed, precipitation, temperature and humidity are the main influencing factors affecting the atmospheric concentration of EPFRs in the autumn and winter. The main performance is that the concentrations of PM2.5, NO2, O3 and CO are positive contributors to the concentration of EPFRs in the air, while wind speed, precipitation, temperature and humidity are negative contributors to the concentration of EPFRs in the air. In the spring and summer, with high temperature, high humidity, high precipitation and high O3 concentration, the concentration of EPFRs in the air is significantly reduced. In addition, this study found that the interaction between contaminants affects the concentration of EPFRs in the air.
       3. The mean concentration of 19 Cl-PAHs and 19 Br-PAHs in the stack gas samples emitted from iron ore sintering process, secondary aluminum smelting process and secondary lead smelting process were 68.3-156.3 ng Nm-3 and 2.9-13.5 ng Nm-3, respectively. The profiles of Cl / Br-PAHs in the ambient air around the three metal smelting processes were tested. The results showed that the concentration of Cl-PAHs ranged from 7.0 to 554 pg m-3, and the concentration of Br-PAHs ranged from 3.0 to 126 pg m-3. A comparison of Cl / Br-PAH congener profiles between ambient air and stack gas indicates that emissions from metallurgical processes affect the surrounding environment to some extent. The toxic equivalent (TEQ) concentrations of Cl-PAHs and Br-PAHs in ambient air samples were 0.03-3.61 pg TEQ m-3 and 0.001-0.23 pg TEQ m-3, respectively. These TEQs are slightly higher than or comparable to the TEQs of dioxins and dioxins like compounds, indicating that Cl / Br-PAHs should be considered when assessed the emission risks of metal smelting processes. The congener profiles of Cl-PAHs emitted from iron ore sintering process, secondary aluminum smelting process and secondary lead smelting process are significantly different from those of the waste incineration process, which can be used for traceability.

Document Type学位论文
Recommended Citation
GB/T 7714
许杨. 新型有机污染物的来源和污染特征分析[D]. 北京. 中国科学院生态环境研究中心,2019.
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