Fu Shuang, Liu Pengfei, He Xiaowei, Song Yifei, Liu Junfeng, Zhang Chenglong, Mu Yujing
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2023 Nov 10;898:165350. doi: 10.1016/j.scitotenv.2023.165350. Epub 2023 Jul 5.
Despite considerable decreases in fine particulate matter (PM) in Chinese megacities over the past decade, many second- and third-tier cities that distribute abundant industrial enterprises are still facing great challenges for PM further reduction under the recent policy background of eliminating heavily-polluted weather. In view of core effects of NO on PM, the deeper reductions of NO in these cities are expected to break the plateau of PM decline, however, the link between NO emission and PM mass loading is currently lacking. Herein, we progressively construct an evaluation system for PM productions based on daily NO emissions in a typical industrial city (Jiyuan), considering a sequence of nested parameters involving evolutions of NO into nitric acid and then nitrate, and contributions of nitrate to PM. The evaluation system was subsequently validated to better reproduce real increasing processes for PM pollution based on 19 pollution cases, with root mean square errors of 19.2 ± 16.4 %, suggesting the feasibility of developing NO emission indicators linked to goals of mitigating atmospheric PM. Additionally, further comparative results reveal that currently high NO emissions in this industrial city severely hinder the achievement of atmospheric PM environmental capacity targets, especially in the scenarios of high initial PM level, low planetary boundary layer height and long pollution duration. It is anticipated that these methodologies and findings would supply guidelines for further regional PM mitigation, in which source-oriented NO indicators could also provide some orientations for industrial cleaner production such as denitrification and low nitrogen combustion.
尽管在过去十年里中国特大城市的细颗粒物（PM）大幅减少，但许多分布着大量工业企业的二三线城市，在近期消除重污染天气的政策背景下，PM进一步减排仍面临巨大挑战。鉴于NO对PM的核心影响，预计这些城市进一步降低NO有望打破PM下降的瓶颈，然而，目前尚缺乏NO排放与PM质量负荷之间的联系。在此，我们基于典型工业城市（济源）的每日NO排放，逐步构建了一个PM生成评估系统，考虑了一系列嵌套参数，包括NO演变成硝酸进而硝酸盐的过程，以及硝酸盐对PM的贡献。随后，基于19个污染案例对该评估系统进行了验证，以更好地重现PM污染的实际增加过程，均方根误差为19.2±16.4%，这表明制定与减轻大气PM目标相关的NO排放指标是可行的。此外，进一步的对比结果表明，该工业城市目前的高NO排放严重阻碍了大气PM环境容量目标的实现，尤其是在初始PM水平高、行星边界层高度低和污染持续时间长的情况下。预计这些方法和研究结果将为进一步的区域PM减排提供指导，其中以源为导向的NO指标也可为工业清洁生产（如脱硝和低氮燃烧）提供一些方向。
