西安冬季重污染过程PM2.5理化特征及来源解析

基于单颗粒气溶胶质谱仪（SPAMS）观测数据、颗粒物质量浓度数据和气象要素数据，研究了2017年11月西安市一次重污染过程中细颗粒物的化学组分特征及其成因，并使用正矩阵因子分析法（PMF）对细颗粒进行了来源解析.结果表明，西安市冬季重污染过程中细颗粒物主要类型为有机碳（OC）、元素碳（EC）、混合碳（ECOC）、富钾（K）、钠-钾（Na-K）、有机胺（amine）、矿尘（dust）和重金属（HM），其主要来源为燃煤（24.9%），二次（29.3%），工业（19.3%），交通（13.3%），生物质燃烧（5.2%）和扬尘（1.9%）.通过对比分析不同污染过程细颗粒物的理化特征，发现高湿度，低风速的不利气象条件和供暖及工业生产导致的燃煤污染、二次污染，是此次重污染过程的主因.

Pollution characteristics and source apportionment of fine particles during a heavy pollution in winter in Xi'an City

Single Particle Aerosol Mass Spectrometry (SPAMS), combining with particulate matter mass concentration and meteorological conditions, was used to study the chemical composition characteristics and genesis of fine particles in a heavy pollution process in November 2017, Xi'an. In addition, the source apportionment of fine particulate matter was analyzed by positive matrix factor analysis (PMF). The results showed that atmospheric particulate matter was mainly divided into eight kinds of particles:organic carbon (OC), elemental carbon (EC), ECOC, K, Na-K, amine, mineral dust, and heavy metal (HM). Their possible sources include coal (24.9%), secondary (29.3%), industry (19.3%), traffic (13.3%), biomass combustion (5.2%), and dust (1.9%). By comparing and analyzing the pollution characteristics of fine particulate matter in different pollution processes, it was found that the main reasons of this heavy pollution process were unfavorable meteorological conditions of high humidity and low wind speed, coal-burning pollution and secondary pollution caused by heating and industrial production.