北京森林大气PM_(2.5)中水溶性无机离子垂直分布特征  

On the vertical distribution of the water-soluble inorganics in PM_(2. 5) in the forests of Beijing area

作　　者：李仁娜[1] 孙丰宾[2] 伦小秀[1] 马伟芳[1] 余新晓[2] 

机构地区：[1]北京林业大学环境科学与工程学院,北京100083 [2]北京林业大学水土保持学院,北京100083

出　　处：《安全与环境学报》2014年第6期262-266,共5页Journal of Safety and Environment

基　　金：国家林业公益性行业科研专项(20130430104);北京林业大学本科生科技创新专项计划项目(xs2014022);北京林业大学大学生创新创业训练计划项目(x1310022123)

摘　　要：研究了城市森林生态系统PM2.5及其组分的垂直分布,在北京市奥林匹克森林公园内的监测塔上,分别于冬季(树木无叶期)和春季(幼叶期)开展观测,观测了Na+、NH+4、K+、Mg2+、Ca2+、Cl-、NO-3和SO2-4的质量浓度。结果表明,SO2-4和NO-3为PM2.5水溶性无机离子的主要成分,其质量浓度之和占总PM2.5水溶性无机离子质量浓度的50%以上。冬季ρ(NO-3)/ρ(SO2-4)为0.525,春季为0.611,表明移动源的影响明显小于固定源。水溶性无机离子质量浓度在一天内出现两个高峰值,分别在6:00—10:00和18:00—22:00,总的趋势是白天质量浓度高于夜晚,这与周围生活环境和气象等因素有密切关系。无叶期时,8种离子质量浓度随高度增加没有明显变化特征;幼叶期时,PM2.5水溶性离子质量浓度随垂直高度增加而增加,在不同垂直高度上有明显的质量浓度梯度变化。In order to evaluate the effect of forest ecological system on the PM2.5 dismissing, the paper has carried out an investigation over the forest function in Beijing in regulating the air pollution emission during the winter （period for trees falling off leaves ） and the spring （period for trees growing their leaves） respectively. The experimental spot we have chosen is situated in a forest area near Beijing Olympic Forest Park, where there is installed a huge tower. We have collected the PM25-polluted leave samples at the different heights, respectively of 1.5 m, 9 m and 15 m. When we collected and put the PM2.5 samples under our test in the quartz filters, we have obtained the quantity of PM2.5 samples by weighing method. As a result, we have analyzed the water soluble leaves and gained the inorganic contents in PM2.5 from the samples filtered. We have found the aforementioned contents by the ion chromatography, which can be stated as follows ： the eight ionsare Na＋ , NIL＋ , K＋ , Mg2＋ , Ca2＋ , Cl- , NO3- and SOl- . The average content rate of the eight ions account for 56.896 μg/m3 in winter and 41.688 μg/m3 in spring. As compared with the concentration rate of such ions, it has been detected that SOl- and NO3- are the main components of the water-soluble inorganic ions in PM2.5. Among the pollutants discovered from the analysis, the rate of concentration of SOl- account for over 50% of the total water-soluble ones. In winter, the molar concentration rate of NO3- and SOl- account for 0.525, whereas they are 0.457 in spring, respectively. This shows that the mobile pollution sources contribute to the total pollution source less than the stationary ones. The chief pollution source of the atmospheric PMz.s in Beijing municipality remains coal-burning. Particularly in winter, the rate of molar concentration equivalent of （SO2- ＋ NO3- ）/NIL＋ accounts for 1.973, whereas that in spring is 1.685, which indicates that PM2.5 turns to be acidic, especially in winter. Moreover, two peaks tend to

关 键 词：环境学 PM2.5 水溶性无机离子 森林生态系统 垂直分布 

分 类 号：X513[环境科学与工程—环境工程]