襄阳市一次大气污染过程中PM_2.5组分及污染源解析

Component and Source Apportionment of PM_2.5 in an Air Pollution Weather in Xiangyang

摘要: 利用单颗粒气溶胶质谱仪对襄阳市2019年1月1日至20日期间的大气PM_2.5组分及污染来源进行了研究。研究表明，监测期间本地大气以机动车尾气的影响为主，此外燃煤、工业工艺源的贡献率也在10%以上。监测期间出现持续大气污染过程，其中轻度、中度及重度污染级别天气的发生，成分方面表现为首要成分元素碳占比的增加，污染源则主要受机动车尾气的大量累积及颗粒物的二次转化影响。严重污染天气时，成分方面表现为混合碳、有机碳和富钾等成分占比增加以及元素碳始终保持为首要成分，污染源方面除受到机动车尾气的影响外，还明显受到燃煤和工业工艺源的影响。此外，研究还发现监测期间本地大气颗粒物的老化程度较高，且持续重污染天气的发生与颗粒物老化程度较高有一定关系。

Abstract: A single particle aerosol mass spectrometer (SPAMS) was deployed in Xiangyang city from January 1 to 20 in 2019 to study the component and sources of PM_2.5. According to the monitoring result, the local atmosphere was mainly affected by motor vehicle exhaust, and the proportion of coal-fired and industrial process sources were also above 10% in addition. During the monitoring period, a con-tinuous air pollution process occurred. When the lightly polluted weather, moderately polluted weather, and heavily polluted weather occurred, the proportion of elemental carbon as a primary component increased and the source of pollution was mainly affected by the massive accumulation of vehicle exhaust and the secondary conversion of particulate matter. When the severely polluted weather occurred, the proportion of mixed carbon, organic carbon and potassium-rich components increased, and elemental carbon remained the primary ingredient. In terms of pollution sources, apart from to the effects of vehicle exhaust, it was also significantly affected by coal and industrial process sources. The study also founded that the local atmospheric particulate matter was highly aged during the monitoring period, and the occurrence of sustained heavy pollution weather had a certain relationship with the higher degree of aging of particulate matter.