庐山大气中多环芳烃的沉降特征研究

发布时间：2018-04-27 01:31

本文选题：多环芳烃 + 云雾水　；参考：《山东大学》2015年硕士论文

【摘要】：多环芳烃作为在自然界广泛存在的持久性有机污染物(POPs),基本上在大气、水体、沉积物、土壤、植被等各种自然环境介质中均有不同程度的检出。人类也会在日常生活中通过皮肤、呼吸道、消化道等途径接触到不同来源的多环芳烃,导致皮肤癌、肺癌等疾病发病率的增加。本研究于2011年8月-9月和2012年3月-5月在庐山进行云雾水、雨水以及大气样品的采集,分析了多环芳烃的浓度水平、分布特征、沉降特征,并对人体致癌风险和生态风险进行评价。庐山云雾水样品中,总多环芳烃的平均浓度(包括可溶相和不溶相)为819.90ng/L,其中菲、芴为含量最多的污染物质,其浓度分别为295.38ng/L和251.98ng/L,对总多环芳烃的贡献率分别为33.11%和28.24%。云雾水中轻环多环芳烃(LMW)所占比例明显高于高环多环芳烃(HMW)。云雾水中可溶相多环芳烃浓度占总浓度的77.45%。有较高的浓度在春季,而夏季浓度则较低。春季多环芳烃总浓度平均值为912.66 ng/L,而夏季多环芳烃总浓度平均值为430.35 ng/L。庐山雨水样品中,总多环芳烃(包括可溶相和不溶相)的平均浓度为236.38ng/L。从PAHs种类上来看,雨水中含量最多的单体为PhA和Flu,分别占总多环芳烃浓度的63.17%和22.82%。雨水中所检测出的多环芳烃主要以2-4环低分子量多环芳烃为主,高分子量多环芳烃大部分未检测出,并且检测出的含量较低。雨水中可溶相多环芳烃浓度明显高于不溶相多环芳烃,占总多环芳烃浓度的77.32%。将一组来自同一气流来向的时间相近的云雾事件和降水事件进行浓度比较分析,云雾水中多环芳烃浓度是雨水中多环芳烃浓度的1.80倍。庐山大气样品中,庐山春季大气中总多环芳烃(气相+颗粒相)平均浓度值为46.32 ng/m3；庐山夏季大气中总多环芳烃(气相+颗粒相)平均浓度值为35.96ng/m3;春季庐山大气中多环芳烃浓度相对较高,夏季多环芳烃浓度相对较低。在所有采集的样品中,苯并(a)的浓度都远低于GB 3095—2012《环境空气质量标准》一级标准限值(2.5 ng/m3)。挑选出一组云雾发生时间(Apri.20-21,云雾持续时间较长)与云前云后大气样品采样时间相近的数据,用来研究大气中多环芳烃云沉降过程。当云雾发生后,两相中(气相+颗粒相)各多环芳烃单体浓度都呈现出明显的下降趋势。云雾总清除率(气相+颗粒相)变化范围为4.69×103 (InP)-7.93×104 (BaA)。气相多环芳烃的清除在云雾过程中处于主导地位。庐山颗粒物中以苯并(a)芘为参照的八种分子量228的多环芳烃单体的总致癌等效浓度TEQΣ8PAH以及总致突变等效浓度MEQΣ8PAH分别为3.172 ng/m3和1.419 ng/m3,分别为单一苯并(a)芘浓度的6.34倍和2.84倍。成人和儿童的多环芳烃终身致癌超额危险度为2.89×104和1.83×104。庐山云雾水和雨水中多环芳烃会对生态系统产生一定的危害,并且春季云雾水生态风险高于夏季云雾水。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs), as persistent organic pollutants (pops) widely present in nature, can be detected in various natural environment media, such as atmosphere, water, sediment, soil, vegetation and so on. People will also be exposed to polycyclic aromatic hydrocarbons (PAHs) from different sources through skin, respiratory and digestive tract in their daily life, resulting in an increase in the incidence of skin cancer, lung cancer and other diseases. In this study, samples of cloud and mist water, Rain Water and atmosphere were collected in Lushan Mountain from August to September 2011 and from March to May 2012. The concentration, distribution and sedimentation characteristics of PAHs were analyzed. The risk of human carcinogenesis and ecological risk were evaluated. The average concentration of total polycyclic aromatic hydrocarbons (including soluble phase and insoluble phase) was 819.90 ng / L in cloud and mist water samples of Lushan Mountain. The concentrations of phenanthrene and fluorene were 295.38ng/L and 251.98 ng / L, respectively, and the contribution rates to total PAHs were 33.11% and 28.2424 ng / L, respectively. The proportion of light ring polycyclic aromatic hydrocarbons (LMWs) in cloud water is significantly higher than that in high ring polycyclic aromatic hydrocarbons (HMWs). Soluble phase polycyclic aromatic hydrocarbons (PAHs) in cloud and mist water account for 77.45% of the total concentration. There were higher concentrations in spring and lower concentrations in summer. The average total concentration of PAHs in spring was 912.66 ng / L, while that in summer was 430.35 ng / L. The average concentration of total polycyclic aromatic hydrocarbons (including soluble phase and insoluble phase) in Rain Water sample of Lushan Mountain is 236.38 ng / L. According to the species of PAHs, PhA and Fluo were the most abundant monomers in Rain Water, accounting for 63.17% and 22.82% of total PAHs, respectively. The polycyclic aromatic hydrocarbons (PAHs) detected in Rain Water were mainly 2-4 ring low molecular weight polycyclic aromatic hydrocarbons (PAHs), but most of HMWHPAs were not detected, and the detected contents were relatively low. The concentration of soluble polycyclic aromatic hydrocarbons (PAHs) in Rain Water was significantly higher than that in insoluble PAHs, accounting for 77.32g of the total PAHs concentration. The concentration of polycyclic aromatic hydrocarbons (PAHs) in cloud and mist water is 1.80 times higher than that in Rain Water. In the atmosphere samples of Lushan, The mean concentration of total polycyclic aromatic hydrocarbons (gas phase particle phase) in the atmosphere in Lushan in spring is 46.32 ng / m ~ (3), the average concentration of total polycyclic aromatic hydrocarbons (gas phase) in the atmosphere in Lushan is 35.96 ng / m ~ (3) in summer, and the concentration of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Lushan Mountain in spring is relatively high. The concentration of PAHs is relatively low in summer. In all the samples collected, the concentration of Benzo a is much lower than the first class limit of GB3095-2012 (ambient air quality standard), which is 2.5 ng / m ~ (3). A group of data, which is similar to the sampling time of atmosphere sample after cloud front cloud, is selected to study the precipitation process of polycyclic aromatic hydrocarbons (PAHs) cloud in the atmosphere, which is similar to the sample time of cloud and mist occurrence time (Apri.20-21, the duration of cloud fog is longer). When the cloud and fog occurred, the concentration of PAHs in the two phases (gas phase particle phase) showed an obvious downward trend. The total clearance rate of cloud and mist (gas phase particle phase) varied from 4.69 脳 10 ~ 3 to 7.93 脳 10 ~ 4 of BaAX. The scavenging of gaseous polycyclic aromatic hydrocarbons (PAHs) is dominant in the process of cloud and mist. The total carcinogenic equivalent concentrations (TEQ 危 8PAH) and total mutagenic equivalent concentrations (MEQ 危 8PAH) of eight PAHs with a molecular weight of 228 in Lushan particulate matter were 3.172 ng/m3 and 1.419 ng / m3, respectively, which were 6.34 times and 2.84 times as much as that of single benzopyrene, respectively. The lifetime risk of polycyclic aromatic hydrocarbons (PAHs) was 2.89 脳 10 ~ 4 and 1.83 脳 10 ~ 4 in adults and children. Cloud water in Lushan Mountain and polycyclic aromatic hydrocarbons (PAHs) in Rain Water could harm the ecosystem, and the ecological risk of cloud water in spring was higher than that in summer.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X51

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