【作者】 杨芳；

【导师】 翟云波；

【作者基本信息】 湖南大学 ， 环境科学与工程， 2010， 硕士

【摘要】 多环芳烃(PAHs)是一类对环境和人类健康危害较大的、具有致癌、致畸和致突变作用的半挥发性有机物。国内外研究人员都逐渐着手对PAHs进行研究。本文以长沙市为例,选取三个采样点,于夏、秋季采集TSP样本,研究长沙市PAHs的浓度、分布及来源。TSP样品采集于2008年5月和2008年9月。在三个点采样,分别是长沙市环保局采样点(A),湖南师范大学附属中学采样点(B),雨花区民政学院采样点(C)。每个采样点采样4或者5天,每次采样8小时,采样为分批进行。本研究采用玻璃纤维滤纸作为采样滤膜,利用硅胶柱层析方法,层析后的PAHs利用GC/MS定性定量。并利用PAHs的特征比值法和因子分析中的主成分分析法对长沙市TSP中PAHs的来源进行解析。夏季TSP浓度分布从195.5到351.7gg/m3,秋季TSP浓度分布从165.6到250.6μg/m3。采样温度和TSP浓度间没有明显的相关关系。夏季A,B,C三个采样点16种PAHs的总浓度范围分别从30.009ng/m3到35.814ng/m3,18.066ng/m3到22.446ng/m3,22.640ng/m3到30.030ng/m3；秋季A,B,C三个采样点16种PAHs的总浓度范围分别从8.314ng/m3到31.703ng/m3,15.191ng/m3到19.204ng/m3,12.448ng/m3到18.626ng/m3。在夏季和秋季两个季节中,没有相同的单个PAHs比例都大于10%,说明单个PAHs的浓度在不同的季节会有所变化。单个多环芳烃浓度之间的比值在A采样点范围为0.058到11.711；B采样点为0.192到3.635；C采样点为从0.060到10.692。这些数据都表明单个多环芳烃浓度没有明显的季节变化,但是有一些细微的季节性。这说明多环芳烃组成不仅受一些季节性来源的影响,更重要的是源自于不受季节影响的来源。根据的单个多环芳烃浓度特征比值初步推断各地多环芳烃污染来源。结果表明在本研究采样期间长沙市大气颗粒物上多环芳烃污染来源主要是燃烧(煤炭燃烧、木材燃烧、汽油和柴油燃烧等)。根据因子分析中的主成分分析法,长沙市夏季多环芳烃的主要来源为交通污染、天然气燃烧及其它燃烧源；秋季多环芳烃的主要来源为汽油燃烧排放、燃烧源、天然气和焦炉。更多还原

【Abstract】 PAHs pollution has been proved to be mutagenic and/or carcinogenic, and thus directly posing threats to human population. So the study of PAH pollution is important. But for the limited conditions, the objectives of this paper are confined only to the study of PAHs levels, their distribution patterns, and the seasonal variation characterization and source identification of PAHs bound to TSP in Changsha.Sampling of ambient air TSP-bound PAHs was performed at several sites (A, B, C) during summer and autumn of 2008 in Changsha, Hunan province, P.R. China. Samples were collected from three sites:the city environmental protection agency of Changsha (A), the Middle School Attached to Hunan Normal University (B) and Yuhua district (C).Glass fiber filters were used to determine the concentration of total suspends particulate (TSP). Particulate matter was extracted in an ultrasonic bath. The concentrated extracts were fractionated by column chromatography to separate PAHs from other polar organic interfering materials. The PAHs were identified by means of a gas chromatography coupled with a mass spectrometry detector. The detection mode used for the identification was selective ion monitoring (SIM).According to the sampling results, TSP concentrations ranged from 195.5 to 351.7μg/m3 in the summer and from 165.6 to 250.6μg/m3 in the autumn. There was no significant correlation between temperature and the level of TSP.The total of 16 PAHs concentrations of summer at site A, B, C ranged from 30.009 ng/m3 to 35.814 ng/m3,18.066 ng/m3 to 22.446 ng/m3, and 22.640 ng/m3 to 30.030 ng/m3, respectively; while the values for autumn at site A, B, C were 8.314 ng/m3 to 31.703ng/m3,15.191ng/m3 to 19.204ng/m3, and 12.448ng/m3 to 18.626ng/m3, respectively. The mean concentrations of PAHs at A site were 0.57 times higher than those measured at B site, and 0.38 times higher than at C site.The ratios of individual PAHs ranged from 0.058 to 11.711 for site A, from 0.192 to 3.635 for site B and from 0.060 to 10.692 for site C. These indicate no significant seasonal variations of individual PAHs concentrations. This fact suggested that the ambient PAHs could be affected by vehicles and stationary sources which were a few seasonal differences.Different profiles and distribution patterns of individual PAHs were characteristic of different pollution sources. These results suggested that the major polluting sources in the Changsha region during the studied period were the burning of fuels, such as diesel oil and gasoline, wood and coal.As the PC A conclusion, in summer, the major sources of PAHs were vehicle emissions, natural gas combustion, and combustion. In autumn, the major sources of PAHs were gasoline emissions, combustion source, and natural gas combustion, and coke oven.The determined factors accounted for over 85.8% and 89.9% of the total data variance for summer and autumn samples, respectively. Varimax rotated factor analysis for samples taken during summer and autumn samples showed three and four possible factors indicating three and four different contributing sources for the PAHs during the two seasons, respectively.更多还原