College of Resource and Environment, Henan Polytechnic University, Jiaozuo 454003, China.
Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2023 Dec 15;904:166857. doi: 10.1016/j.scitotenv.2023.166857. Epub 2023 Sep 9.
Despite the significant reduction in atmospheric pollutant levels during the COVID-19 lockdown, the presence of haze in the North China Plain remained a frequent occurrence owing to the enhanced formation of secondary inorganic aerosols under ammonia-rich conditions. Quantifying the increase or decrease in atmospheric ammonia (NH) emissions is a key step in exploring the causes of the COVID-19 haze. Historic activity levels of anthropogenic NH emissions were collected through various yearbooks and studies, an anthropogenic NH emission inventory for Henan Province for 2020 was established, and the variations in NH emissions from different sources between COVID-19 and non-COVID-19 years were investigated. The validity of the NH emission inventory was further evaluated through comparison with previous studies and uncertainty analysis from Monte Carlo simulations. Results showed that the total NH emissions gradually increased from north-west to south-east, totalling 751.80 kt in 2020. Compared to the non-COVID-19 year of 2019, the total NH emissions were reduced by approximately 4 %, with traffic sources, waste disposal and biomass burning serving as the sources with the top three largest reductions, approximately 33 %, 9.97 % and 6.19 %, respectively. Emissions from humans and fuel combustion slightly increased. Meanwhile, livestock waste emissions decreased by only 3.72 %, and other agricultural emissions experienced insignificant change. Non-agricultural sources were more severely influenced by the COVID-19 lockdown than agricultural sources; nevertheless, agricultural activities contributed 84.35 % of the total NH emissions in 2020. These results show that haze treatment should be focused on reducing NH, particularly controlling agricultural NH emissions.
尽管 COVID-19 封锁期间大气污染物水平显著降低，但由于富氨条件下二次无机气溶胶的增强形成，华北平原仍频繁出现雾霾。量化大气氨（NH）排放的增加或减少是探索 COVID-19 雾霾原因的关键步骤。通过各种年鉴和研究收集了人为 NH 排放的历史活动水平，建立了 2020 年河南省人为 NH 排放清单，并研究了 COVID-19 年和非 COVID-19 年不同来源的 NH 排放变化。通过与先前研究的比较和蒙特卡罗模拟的不确定性分析进一步评估了 NH 排放清单的有效性。结果表明，NH 排放总量从西北向东南逐渐增加，2020 年总计为 751.80 kt。与 2019 年的非 COVID-19 年相比，总 NH 排放量减少了约 4%，其中交通源、废物处理和生物质燃烧是排放量减少最多的三个来源，分别减少了约 33%、9.97%和 6.19%。人类和燃料燃烧的排放量略有增加。同时，牲畜废物排放量仅减少了 3.72%，其他农业排放量变化不大。非农业源受 COVID-19 封锁的影响比农业源更严重；然而，农业活动在 2020 年贡献了总 NH 排放量的 84.35%。这些结果表明，雾霾处理应侧重于减少 NH，特别是控制农业 NH 排放。
