【作者】 刘晓燕；

【导师】 李一凡；

【作者基本信息】 哈尔滨工业大学 ， 环境工程， 2019， 硕士

【摘要】 多环芳烃是环境中的一类典型有毒有机污染物,具有“三致”效应,并且具有持续扩散的特征。干沉降对于大气中PAHs具有清除作用,同样湿沉降对于大气中PAHs也具有清除作用,干湿沉降对于大气中PAHs发挥着举足轻重的作用。对于PAHs的干沉降,东北地区缺乏此部分的数据研究,而对于PAHs湿沉降研究,很多地区只研究了降雨特征而对降雪研究很少,所以我们本文针对采集的2017～2018年的大气、干沉降、降雨以及降雪样品对PAHs的大气干湿沉降特征展开研究。本研究采集大气、干沉降、降雨以及降雪样品预处理后,使用气相色谱-质谱联用仪检测分析样品中PAHs含量。本研究中大气、干沉降、降雨和将雪中Σ₁₆PAHs平均浓度分别为:93.02±94.83 ng·m^-3、5244.73±6066.18 ng·g^-1、15732.14±9233.67 ng·L^-1以及35373.52±23032.12 ng·L^-1,与国内外其他地区相比,可以得到本研究中污染水平处于世界中等污染水平,且大气、干沉降、降雨以及降雪中Σ₁₆PAHs平均浓度在供暖期和非供暖期具有明显差异。在关于干湿沉降特征的研究中,通过大气气相干沉降通量为:1068.15±1252.77 ng·m^-2·d^-1,大气颗粒相干沉降通量为1666.03±2029.49 ng·m^-2·h^-1,大气气相和颗粒相干沉降通量在供暖期和非供暖期具有明显差异。降雨和降雪对大气中PAHs的清除率数量级分别为10⁸和10⁷,其比经验值高两个数量级。降雨和降雪沉降过程中的Σ₁₆PAHs平均沉降通量分别为:2406.95 ng·m^-2·d^-1和3520.71 ng·m^-2·d^-1,本研究中湿沉降通量与国内外其他地区相比,哈尔滨市PAHs湿沉降通量处于较高的污染水平,处于世界中等水平。通过应用特征分子比值法和主成分分析法,我们发现在供暖期对哈尔滨大气中PAHs影响因素最大的为燃煤供暖,而非供暖期则影响因素较多,根据哈尔滨PAHs的来源来说,主要应该控制在冬季燃煤的控制,使用清洁燃煤,提高能源的利用率。更多还原

【Abstract】 Polycyclic aromatic hydrocarbons（PAHs）are a persistent organic pollutant in the atmosphere with a"triad"effect and characterized by sustained diffusion.Dry deposition has a scavenging effect on PAHs in the atmosphere.Similarly,wet deposition has a scavenging effect on PAHs in the atmosphere too.Dry and wet sedimentation plays an important role in atmospheric PAHs.For dry deposition of PAHs,a lack of this part in the northeast of data research,for the PAHs wet deposition research,many areas only studied the characteristics of rainfall and snowfall research rarely.Therefore,this paper studies the characteristics of atmospheric dry and wet deposition of PAHs collected from atmospheric,dry deposition,rainfall and snowfall samples in 2017-2018.In this study,samples of atmospheric,dry deposition,rainfall and snowfall were collected meanwhile samples of atmospheric particulate phase deposition were pretreated.The content of PAHs in samples was determined by gas chromatography-mass spectrometry（GC-MS）.The average concentrations ofΣ₁₆PAHs in atmosphere,dry deposition,rainfall and snow are 93.02±94.83 ng·m^-3,5244.73±6066.18 ng·g^-1,15732.14±9233.67 ng·L^-1 and 35373.52±23032.12 ng·L^-1 respectively.Compared with the results reported at home and abroad,the pollution level in this study is in the middle rank in the world,the mean concentration ofΣ₁₆PAHs in the atmosphere,dry deposition,rainfall and snowfall is significant difference between heating and non-heating periods.In the study of the characteristics of dry and wet deposition,the atmospheric coherent deposition flux is:1068.15±1252.77 ng·m^-2·d^-1,coherent deposition flux of atmospheric particles is 1666.03±2029.49 ng·m^-2·h^-1.The coherent deposition flux of atmospheric gas phase and particle has obvious difference in heating period and non-heating period.The removal rates of PAHs by rainfall and snowfall are 10⁸and 10⁷ orders of magnitude,respectively,and is two orders of magnitude higher than the rule of thumb.The average precipitation flux ofΣ₁₆PAHs during precipitation and snow deposition is 2406.95 ng·m^-2·d^-1 and 3520.71 ng·m^-2·d^-1,respectively.Compared with the results reported at home and abroad,the wet deposition flux of PAHs in Harbin is at a high pollution level,which is in the middle of the world.Through the application of characteristic molecule ratio method and principal component analysis method,it is found that coal combustion in heating period has the greatest impact on Harbin,and the influence of various factors in non-heating period is more complex,the influence of automobile exhaust is more obvious,according to the sources of PAHs in Harbin,we should mainly control coal burning in winter,use clean coal burning and improve energy utilization.更多还原