南昌市2021年春季大气VOCs污染特征和来源分析

2021年2~4月，利用AQMS-900VCM大气挥发性有机物在线监测系统对南昌市经济技术开发区大气中114种挥发性有机化合物（VOCs）进行了在线观测，分析了春季南昌市大气中VOCs浓度水平、日变化，估算了各种VOCs的臭氧生成潜势（OFP），并基于PMF模型探讨了VOCs的来源.结果表明，南昌市经济技术开发区2021年2~4月VOCs体积浓度为（146±40.1）×10^-9，其中烷烃是主要的VOCs贡献者，占TVOCs的（56.6±19.1）%，其次是含氧挥发性有机物（OVOCs）和卤代烃，分别占TVOCs的（14.9±6.13）%和（14.8±5.12）%.TVOCs浓度在白天高于晚上，这可能与白天人为活动有关.OFP主要受烷烃、芳香烃和OVOCs影响，其对臭氧生成潜势贡献分别为36.0%，29.5%和23.0%.PMF结果显示，南昌市2021年春季大气VOCs的主要来源分别为燃烧源（22.5%），天然源（22.1%），油气挥发源（21.1%），机动车排放源（17.7%）与溶剂使用和工业源（16.6%）.

Characteristics and sources of atmospheric VOCs during spring of 2021 in Nanchang

Total of 114 volatile organic compounds(VOCs) were measured by AQMS-900 VCM online monitoring system from February to April 2021 in Nanchang. We analyzed concentration and diurnal variations of VOCs species, estimated the Ozone formation potential(OFP) by various VOCs, and explored the possible sources of VOCs by Positive Matrix Factorization(PMF) model. The volume concentration of total VOCs(TVOCs) in Nanchang spring was(146±40.1)×10^-9. Alkanes, oxygenated volatile organic compounds(OVOCs) and halogenated hydrocarbons were the main contributors of VOCs, accounting for(56.6±19.1)%,(14.9±6.13)% and(14.8±5.12)% of TVOCs, respectively. Daily TVOCs concentrations were higher than those during night,suggested the influences of human activities on TVOCs. The estimated OFP was mainly affected by alkanes, aromatic hydrocarbons and OVOCs, and their potential contributions to ozone generation were 36.0%, 29.5% and 23.0%, respectively. PMF results showed that combustion source(22.5%), natural source(22.1%), oil and gas volatilization source(21.1%), motor vehicle emission source(17.7%) and solvent use and industrial source(16.6%) were the main sources of atmospheric VOCs in Nanchang in spring of 2021.