State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
Sci Total Environ. 2022 May 15;821:153383. doi: 10.1016/j.scitotenv.2022.153383. Epub 2022 Jan 24.
Secondary inorganic aerosols (SIA) account for 20-60% of the total fine particulates in the Beijing-Tianjin-Hebei (BTH) region of China, indicating an urgent need to clarify the relationship among such compounds. The purpose of this study was to quantify the relationship between emissions of NH, NOx, SO, VOCs and SIA concentrations during a severe winter haze episode using an air quality model and a meteorology-based redistributed NH emission inventory within the BTH region. The results showed that the model performance regarding the NH simulations in January by the four emission inventories improved after the redistribution of daily NH emissions, with an increase of 0.02-0.13 in R, a 9-56% decrease in NMB, and a 7-51% decrease in NME. The updated simulations reproduced the daily observations of SIA, SO, and NO well. A total of 125 sets of sensitivity simulations showed that a synergistic reduction in NH and VOCs was more efficient in terms of SIA control than simply reducing SO or NOx in the BTH region. If only NOx emissions were reduced, the SIA concentration would first increase and then decrease, and it could decline by another 0.86-8.03% in parallel with an equal NH emission cut. SIA could be reduced by approximately 22.68% with the most stringent inorganic precursors' control. Moreover, VOCs emission reductions could lead to a decrease in SIA, and the impact of VOCs on SIA was similar to that of NH. The collaborative control of both inorganic precursors and VOCs was more effective than single-factor control measures for decreasing SIA, and the decline rate was approximately 29.26% under minimum emission conditions. This improved effectiveness was obtained because VOCs mitigation effectively decreases the ozone concentration, which in turn influences SIA formation. Finally, on the premise of a 60% SO cut, the reduction scheme NH:VOCs:NOx = 4:4:1 was suggested for SIA control.
二次无机气溶胶 (SIA) 约占中国京津冀地区细颗粒物总量的 20-60%，表明迫切需要厘清此类化合物之间的关系。本研究旨在利用空气质量模型和重新分配的京津冀地区基于气象学的氨排放清单量化重霾期间 NH、NOx、SO、VOC 和 SIA 浓度排放之间的关系。结果表明，四个排放清单对一月 NH 模拟的模式性能在每日 NH 排放量重新分配后得到改善，R 值增加了 0.02-0.13，NMB 降低了 9-56%，NME 降低了 7-51%。更新后的模拟很好地再现了 SIA、SO 和 NO 的日观测值。总共进行了 125 组敏感性模拟，表明在京津冀地区，NH 和 VOC 的协同减排在控制 SIA 方面比单纯减少 SO 或 NOx 更为有效。如果仅减少 NOx 排放，SIA 浓度将先增加后减少，与等量 NH 排放削减同时可再降低 0.86-8.03%。采用最严格的无机前体控制，SIA 可减少约 22.68%。此外，VOCs 减排会导致 SIA 减少，VOCs 对 SIA 的影响与 NH 相似。无机前体和 VOCs 的协同控制比单一因素控制措施更有效地降低 SIA，在最小排放条件下，下降率约为 29.26%。这种改进的效果是由于 VOCs 缓解有效地降低了臭氧浓度，进而影响了 SIA 的形成。最后，在 60%SO 削减的前提下，提出了 SIA 控制的 NH:VOCs:NOx=4:4:1 减排方案。
