蚌埠市夏季大气细颗粒物在线源解析

为了解蚌埠市环境空气中PM2.5的来源,于2017年8月18日—9月18日,在百货大楼和高新区站点,利用单颗粒物气溶胶飞行时间质谱仪开展PM2.5在线源解析。结果表明,百货大楼点位ρ(PM2.5)高于高新区点位,轻度污染比例(4.2%)明显高于高新区点位(0.8%),出现了中度污染(0.3%);SPAMS的PM2.5质谱图显示百货大楼点位PM2.5中K^+、Na^+特征明显,高新区点位HSO^-4、NO^-3、NO^-2等无机信号较为明显;2个点位NO^-3、NO^-2、NH^+4离子颗粒数占总颗粒数的百分比明显较高,且高新区点位NO^-3、HSO^-4离子数占比要明显高于百货大楼点位,燃料燃烧、工业工艺源、农田氮肥施用是其主要的人为污染源;2个点位PM2.5成分主要为元素碳,分别占比42.4%,40.6%;污染时段,ρ(PM2.5)快速上升,除受本地机动车尾气源和燃煤源累积影响外,百货大楼点位扬尘源排放增加,高新区点位扬尘源和工业工艺排放源增加;2个点位机动车尾气源均为首要污染源,分别占比29.5%和30.9%,其次为燃煤源(24.3%和24.7%),扬尘源占比分别为22.9%和20.8%。

On line Source Apportionment of Atmospheric Fine Particles in Summer, Bengbu

To find out the source of fine particles in the ambient air of Bengbu, on line source apportionment was carried out using Aerosol Time of flight Mass Spectrometer at the commercial residential mixed area (BD) and industrial area (GX), from August 8^th to September 18^th, 2017. The results showed that the PM_2.5 content of BD was higher than that of GX during the observation period, moreover, the proportion of mild PM_2.5 pollution (4.2%) was significantly higher than that of GX (0.8%), and moderate PM_2.5 pollution appeared (0.3%) at BD. SPAMS fine particle matter spectrum showed that K⁺ and Na⁺ characteristics were obvious in fine particles at BD, and inorganic signals such as HSO^-₄, NO^-₃ and NO^-₂ at the point of GX were obvious. The percentages of NO^-₃, NO^-₂ and NH⁺₄ ions in the total number of particles were both significantly high in the two monitoring points, and the proportions of NO^-₃ and HSO^-₄ ions at GX were significantly higher than those at BD, fuel combustion, industrial process sources and nitrogen fertilizer application were the main anthropogenic pollution sources. The fine particles at the two points composed mainly of elemental carbon, accounting for 42.4% and 40.6%, respectively. During the pollution period, PM_2.5 concentration increased rapidly, besides being affected by the accumulation of local motor vehicle exhaust and coal fired sources, both of the increase of dust source emission at BD and GX and the increase of industrial process emission sources at GX made contributions to it. Automobile exhaust fumes were the primary pollution sources, accounting for 29.5% and 30.9%, respectively, followed by coal fired sources (24.3% and 24.7%), with dust sources accounting for 22.9% and 20.8%, respectively.