冬季关中城市及农村颗粒物的污染特征

为比较冬季城市和农村大气颗粒物浓度及化学组分等特征，本文分别采集分析了西安市区、安康农村冬季大气PM2.5颗粒物与PM0.1颗粒物。分析结果表明：两地大气中PM2.5日均浓度均超过国家二级标准（75 μg·m-3），空气质量不容乐观；其中农村样品中PM0.1颗粒物约占PM2.5颗粒物浓度的36.8%左右；所有颗粒物中有机碳远高于无机碳组分，而市区大气颗粒物中多环芳烃浓度显著高于农村浓度，说明城市空气中来源于机动车尾气的污染较为严重；从颗粒物粒径分布特征来看，粒径为0.300~0.374 μm颗粒物具有最高数浓度和比表面积浓度，粒径为0.374~0.465 μm的颗粒物具有最高质量浓度；由于农村污染源较为单一，安康样品颗粒物浓度受燃煤和油烟的影响较大。此外，由于受燃煤机动车排放影响，西安大气中PM0.1颗粒物中水溶性离子主要为NO3-与SO42，而安康大气PM0.1颗粒物中水溶性离子主要以SO42-与Ca2+为主， PM2.5颗粒物中水溶性离子以NO3-、SO42-和NH4+为主，这与农村环境中使用燃煤、农田灌溉、家畜喂养以及有机质降解等有关。

Fundamental research on pollution property of particulates in Guanzhong urban and rural area in southern Shanxi during winters

In order to compare the characteristics of urban and rural atmosphere like atmospheric particle concentration and chemical composition, this paper collected and analyzed the PM2.5 particles and PM0.1 particles of Xi'an and Ankang rural areas in winter. The results show that the PM2.5 atmospheric concentration in the atmosphere of the two places is higher than the National secondary standard (75 μg·m-3), and the air quality is not optimistic. The PM0.1 particles in the rural sample account for about 36.8% of the PM2.5 particle concentration; the Organic carbon component is much higher than the inorganic carbon component in the particles, the polycyclic aromatic hydrocarbon concentration (PAHs) in the atmospheric particles of the Urban area is much higher than the rural area, Indicating that air pollution in the city is more serious caused by the the motor vehicle exhaust;From the view of the particle size distribution of the particles, the particle its size is 0.300 to 0.374 μm have the highest concentration and the specific surface area concentration, and the particle its size is 0.374 to 0.465 μm have the highest mass concentration. Due to the relatively single pollution source, coal and fumes have a greater impact on the particle concentration of Ankang sample. In addition, due to the impact of coal-fired motor vehicle emissions, the water-soluble ions in PM0.1 particles in Xi'an are mainly NO3- and SO42-, and the water-soluble ions in PM0.1 particles are mainly SO42- and Ca2+ The water-soluble ions in the particulate matter are mainly NO3-, SO42- and NH4+, which are related to the use of coal, farmland irrigation, livestock feeding and degradation of organic matter in rural environment.