Carbon components, water-soluble ions and their gaseous precursors in atmospheric PM_2.5 in Taian were monitored online from May 10 to June 10, 2019. The mass concentration and component composition of PM_2.5 (carbonaceous species and water-soluble ions) were analyzed. The results showed that the average mass concentration of PM_2.5 was 37.7 μg/m³ during the sampling period, which was 1.1 times higher than the standardary limit (35 μg/m³) regulated by of Chinese Ambient air quality standards (GB 3095–2012). For instance, the content of water-soluble ions in PM_2.5 was the highest with 47.3%. The water-soluble components of PM_2.5 and gaseous precursors had obvious diurnal variation, with a peak (single peak) at 7:00 am. OC/EC ratio of Taian in summer ranged from 1.1 to 17.5, indicated that Taian was mainly affected by a mixture of biomass combustion, coal combustion and exhaust emissions. Positive matrix factor analysis (PMF) showed that the proportion of secondary nitrate, biomass combustion source, secondary sulfate and coal combustion soure in PM_2.5 were 22.0%, 46.7%, 29.9% and 1.4%, respectively.

PM_2.5, component composition, source analysis, Taian

于2019年5月10日—6月10日对泰安市大气PM_2.5中的碳组分、水溶性离子进行在线监测, 分析PM_2.5及其化学组分的变化特征, 讨论泰安市细颗粒物的主要来源。结果表明, 泰安市夏季PM_2.5的质量浓度为37.7 μg/m³, 是《环境空气质量标准》(GB 3095—2012)二级标准阈值(35 μg/m³)的1.1倍。水溶性离子在PM_2.5中占比最高, 为47.3%。水溶性组分及其气态前体物存在明显的日变化规律, 在早晨7:00出现峰值(单峰)。泰安市夏季OC/EC比值在1.1~17.5 之间, 说明泰安市主要受生物质燃烧、燃煤和尾气排放混合源的影响。正交矩阵因子分析(PMF)结果表明, PM_2.5结果中二次硝酸盐、生物质燃烧源、二次硫酸盐和燃煤源的贡献比分别为 22.0%, 46.7%, 29.9%和1.4%。

PM_2.5, 化学组成, 来源解析, 泰安