近日，天津大学傅平青及其课题组成员，在研究北京雾霾污染期间燃烧相关铵的主要因素中取得一项新成果。该项研究成果发表在2024年1月4日出版的《科学通报》上。

在该项研究中，课题组人员采用实地观察和模型(区域多尺度空气质量，CMAQ)相结合的方法，以调查北京冬季NH₃的区域排放源和垂直分解NH₄⁺的形成机制。稳定氮同位素分析和CMAQ模型均表明，燃烧相关的NH₃排放，包括化石燃料源、NH₃逸出和生物质燃烧，是气溶胶NH₄⁺的重要来源，重污染日的贡献占60%以上。

相比之下，与挥发相关的NH₃源(牲畜养殖、氮肥施用和人类粪便)在清洁日占主导地位。与燃烧相关的NH₃主要来自北京本地，而生物质燃烧可能是一个重要的NH₃来源(约15%-20%)，这一点以前被忽视了。为改善空气质量，应考虑更有效的控制策略，如双产品(如同时减少SO₂和NH₃)控制政策。

据悉，气溶胶铵(NH₄⁺)主要由氨(NH₃)与大气中的酸反应产生，对大气污染、辐射作用力和人类健康有重要影响。了解NH₄⁺的来源及其形成机制，可以为改善空气质量提供科学依据。然而，人们对城市地区NH₃的来源了解不多，对大气边界层内不同高度NH₃/NH₄⁺的研究较少，阻碍了人们对气溶胶NH₄⁺的全面了解。

附：英文原文

Title: Dominant contribution of combustion-related ammonium during haze pollution in Beijing

Author:Libin Wu, Peng Wang, Qiang Zhang, Hong Ren, Zongbo Shi, Wei Hu, Jing Chen, Qiaorong Xie, Linjie Li, Siyao Yue, Lianfang Wei, Linlin Song, Yonggen Zhang, Zihan Wang, Shuang Chen, Wan Wei, Xiaoman Wang, Yanlin Zhang, Shaofei Kong, Bao Zhu Ge

Issue&Volume: 2024/01/04

Abstract: Aerosol ammonium (NH₄⁺), mainly produced from the reactions of ammonia (NH₃) with acids in the atmosphere, has significant impacts on air pollution, radiative forcing, and human health. Understanding the source and formation mechanism of NH₄⁺ can provide scientific insights into air quality improvements. However, the sources of NH₃ in urban areas are not well understood, and few studies focus on NH₃/NH₄⁺ at different heights within the atmospheric boundary layer, which hinders a comprehensive understanding of aerosol NH₄⁺. In this study, we perform both field observation and modeling studies (the Community Multiscale Air Quality, CMAQ) to investigate regional NH₃ emission sources and vertically resolved NH₄⁺ formation mechanisms during the winter in Beijing. Both stable nitrogen isotope analyses and CMAQ model suggest that combustion-related NH₃ emissions, including fossil fuel sources, NH₃ slip, and biomass burning, are important sources of aerosol NH₄⁺ with more than 60% contribution occurring on heavily polluted days. In contrast, volatilization-related NH₃ sources (livestock breeding, N-fertilizer application, and human waste) are dominant on clean days. Combustion-related NH₃ is mostly local from Beijing, and biomass burning is likely an important NH₃ source (～15%–20%) that was previously overlooked. More effective control strategies such as the two-product (e.g., reducing both SO₂ and NH₃) control policy should be considered to improve air quality.

DOI: 10.1016/j.scib.2024.01.002

Source: https://www.sciencedirect.com/science/article/abs/pii/S2095927324000021