襄阳市秋冬季PM2.5污染特征及潜在源区分析

为了解襄阳市秋冬季PM_2.5的污染特征及来源,基于2020年11月至2021年1月在线监测数据,对PM_2.5质量浓度、气象因素、化学组分、来源及潜在源区进行了分析。结果表明,襄阳市秋冬季污染天首要污染物均为PM_2.5,且随污染程度加重,PM_2.5与PM₁₀质量浓度比呈上升趋势,二次颗粒物的形成对PM_2.5的贡献更高。在PM_2.5化学组分中,水溶性离子占比最大,随着污染程度加重,二次离子(SNA)快速增长,二次离子的生成转化是污染的重要成因。轻度、中度污染时,湿度高、风速小、气温低,有利于污染的积累,重度污染时湿度大、风速回升,有利于上游污染的输送与二次转化。PMF模型解析出襄阳市PM_2.5主要来源及贡献率为二次源58.0%、工业企业源22.6%、机动车源10.7%、扬尘源8.7%。襄阳市潜在源区主要分布在河南省中北部、河北省南部、山东省西部、安徽省北部、江汉平原东部及南部区域,极少量分布在襄阳区域,长距离区域传输...

Characteristics and Sources Analysis of PM2.5 in Xiangyang in Autumn and Winter

To study the characteristics and sources of PM_2.5 pollution in Xiangyang in autumn and winter,PM_2.5 mass concentration,meteorological factors,chemical components,sources and potential sources were analyzed based on online monitoring data from November 2020 to January 2021.The results showed that the primary pollutant was PM_2.5 in Xiangyang in autumn and winter,and the mass concentration ratio of PM_2.5 and PM₁₀ showed an increasing trend with the aggravation of pollution degree,and the formation of secondary particulate matter had a higher contribution to PM_2.5.Among chemical components of PM_2.5,water-soluble ions contributed the most.With the aggravation of pollution,secondary ions increased rapidly,and the generation and transformation of secondary ions was an important cause of pollution.In light and moderate pollution,high humidity,low wind speed and low temperature were conducive to the accumulation of pollution.In severe pollution,high humidity and high wind speed were conducive to the transport and secondary transformation of upstream pollution.According to the PMF model,the main sources and contribution rates of PM_2.5 in Xiangyang City were 58.0% from secondary sources,22.6% from industrial enterprises,10.7% from motor vehicles and 8.7% from dust sources.The potential source areas of Xiangyang City were mainly distributed in central and northern Henan Province,southern Hebei Province,western Shandong Province,northern Anhui Province,eastern and southern Jianghan Plain,and a very small amount were distributed in Xiangyang region.Long-distance regional transmission contributed more to its concentration,especially from the southern Hebei and central and northern Henan transmission routes.