标题：Fossil fuel-related emissions were the major source of NH3 pollution in urban cities of northern China in the autumn of 2017
作者：Zhang, Zhongyi; Zeng, Yang; Zheng, Nengjian; Luo, Li; Xiao, Hongwei; Xiao, Huayun
作者机构：[Zhang, Zhongyi; Zheng, Nengjian; Luo, Li; Xiao, Hongwei; Xiao, Huayun] East China Univ Technol, Jiangxi Prov Key Lab Causes & Control Atmospher P, Na 更多
通讯作者地址：[Xiao, HY]East China Univ Technol, Jiangxi Prov Key Lab Causes & Control Atmospher P, Nanchang 330013, Jiangxi, Peoples R China.
关键词：Nitrogen isotope; Ammonium; PM2.5; Batch model; Source apportionment
摘要：As the most important gas-phase alkaline species, atmospheric ammonia (NH3) contributes considerably to the formation and development of fine-mode particles (PM2.5), which affect air quality and environmental health. Recent satellite-based observations suggest that the North China Plain is the largest agricultural NH3 emission source in China. However, our isotopic approach shows that the surface NH3 in the intraregional urban environment of Beijing-Tianjin-Shijiazhuang is contributed primarily by combustion-related processes (i.e., coal combustion, NH3 slip, and vehicle exhaust). Specifically, the Batch fractionation model was used to describe the partitioning of gaseous NH3 into particles and to trace the near-ground atmospheric NH3 sources. With the development of haze pollution, the dynamics of delta N-15-NH4+ were generally consistent with the fractionation model. The simulated initial delta N-15-NH3 values ranged from -22.6 parts per thousand to -2.1 parts per thousand, suggesting the dominance of combustion-related sources for urban NH3. These emission sources contributed significantly (92% on hazy days and 67% on clean days) to the total ambient NH3 in urban cities, as indicated by a Bayesian mixing model. Based on the Batch fractionation model, we concluded the following: 1) delta N-15-NH4+ can be used to model the evolution of fine-mode aerosols and 2) combustion-related sources dominate the near-ground atmospheric NH3 in urban cities. These findings highlight the need for regulatory controls on gaseous NH3 emissions transported from local and surrounding industrial sources. (C) 2019 Elsevier Ltd. All rights reserved.