2011年夏季在黄山3个不同高度上设观测点,利用Andersen分级采样器同步采集大气气溶胶,样品用离子色谱仪(Metrohm IC)进行分析.结果表明,山底、山腰和山顶的平均总离子浓度分别为13.32、10.94和9.97μg.m-3,大气气溶胶无机离子成分随高度增加呈递减趋势;黄山大气气溶胶中主要离子质量浓度依次为SO4^2-〉NH4^+〉Ca^2+〉NO3-;NH4^+、SO4^2-分别为最主要的阳离子和阴离子,浓度随高度增加而递减最为显著,两种离子浓度和在3个采样点中均占PM2.1离子质量浓度的75%以上;粗粒子中最主要的阳离子与阴离子则为Ca^2+和NO3-.PM10与PM2.1中阴阳离子线性回归线斜率近似为1,表明黄山大气气溶胶酸碱平衡.相关性分析表明,NH4^+与SO4^2-的相关性高达0.98,这两种离子主要结合成(NH4)2SO4和少量的NH4HSO4存在于颗粒物中.黄山地区气溶胶在一定程度上受到周边地区人为源的影响.后向轨迹模拟显示,黄山夏季气团主要来源于南方沿海、东海、黄海及北方地区.由于途径重污染排放区,北方气团细粒子离子浓度较高,K+离子浓度近为西南气团的数倍.
Aerosol was collected with Anderson cascade sampler at three altitudes of the Mount Huang in the summer 2011.Samples were analyzed by the ion chromatography(IC,Metrohm).The results showed that the mean mass concentrations of all the ions were 13.21 μg·m-3,10.94 μg·m-3,9.97 μg·m-3,at the foot,mid height and the summit of the mountain,respectively.The mass concentration of water-soluble components of aerosol decreased with altitude.The major anion and cation of aerosols were SO4^2- and NH+4,respectively.The descending order of mass concentration of major ionic species was: SO4^2-NH+4Ca^2+NO-3.SO4^2- and NH+4 account for about 75% of total ionic concentrations of PM2.1 in three sampling sites.The concentration of SO4^2- and NH+4 decreased conspicuously with altitude.The major cation and anion of coarse mode particles were Ca^2+ and NO-3,respectively.The slope of the linear regression line between anion and cation of PM10 and PM2.1 approximates 1,indicating acid-base balance in aerosol particles.Aerosols over the region Mount Huang were influenced by anthropogenic source of surrounding areas to a certain extent.The result also suggested that the correlation between NH+4 and SO4^2- was 0.98 and these ions predominantly existed in the form of(NH4)2SO4and NH4HSO4.Backward trajectory analysis revealed that the air mass was originated from southern coastal regions,the East China Sea,the Yellow Sea and the northern China.Due to the northern air masses go through heavily polluted areas,concentrations of water-soluble ions in these air masses were higher than that of other air masses.The concentration of K+ in northern air mass was several times higher than that in southwestern air mass.