2015年石家庄市采暖期一次重污染过程细颗粒物在线来源解析

近年来，我国北方采暖期的大气污染问题备受关注.以2015年11月24日至12月4日石家庄地区一次重污染过程为例，采用大气细颗粒物实时在线源解析技术，对不同时段细颗粒物来源解析结果和各类源粒径分布、重污染期间各类源的质谱特征，结合气象条件进行综合分析.结果表明：重污染期间主要污染物来源为燃煤、工业工艺、机动车尾气和二次无机源；低压、静稳条件和低空传输共同作用下，以燃煤及工业工艺源排放颗粒物为主的细颗粒物严重累积，二次转化加剧，导致此次重污染的发生；来自燃煤源的颗粒物以混合碳为主，工业工艺源以金属为主，机动车尾气源以元素碳和金属锰为主，纯二次无机源以二次无机离子为主，来自扬尘源的颗粒物以铝、钙、铁和硅酸盐为主，生物质燃烧源以左旋葡聚糖LEV为主，餐饮源以有机酸为特征信号；与重污染前后不同，八类源于重污染发生期间在整个粒径段呈现均匀分布状态.

Online Source Analysis of Particulate Matter (PM2.5) in a Heavy Pollution Process of Shijiazhuang City During Heating Period in 2015

In recent years, more and more public attention has been paid to the problem of air pollution during the heating period in North China. This article took a heavy pollution process of Shijiazhuang district from Nov.24^th to Dec.4^th in 2015 as an example, and analyzed comprehensively the source apportionment in different periods, size distribution of the PM_2.5 from each source in different periods, the characteristics of mass spectra of the main emission sources and the meteorological conditions with the method of real-time online source analysis. It turned out:the main sources of pollutants were coal combustions, industrial discharges, vehicle exhausts and secondary inorganic reactions. With the help of meteorological condition of low pressure and low wind speed, the PM_2.5 mainly produced by coal combustions and industrial discharges accumulated heavily and went through the second stage conversion, leading to this heavy air pollution. The main particulate matters from coal combustions were the mixed carbons; the main particulate matters from industrial discharges were metals; the main particulate matters from vehicle exhausts were elemental carbon and manganese metal; the main particulate matters from pure secondary inorganic sources were secondary inorganic ions; the main particulate matters from dust pollution were aluminum, calcium, iron and silicate minerals; the main particulate matters from biomass fuel combustions were levoglucosan; the feature signal from restaurant discharges was organic acid. Different from the distribution before and after the heavy pollution period, the particulate matters from the 8 pollution sources presented even distribution during the heavy pollution period.