Liu Yafei, Yin Shijie, Zhang Siqing, Ma Wei, Zhang Xin, Qiu Peipei, Li Chenlu, Wang Guangpeng, Hou Dongli, Zhang Xiang, An Junling, Sun Yele, Li Jie, Zhang Ziyin, Chen Jing, Tian Hezhong, Liu Xingang, Liu Lianyou
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2024 Jan 1;906:167847. doi: 10.1016/j.scitotenv.2023.167847. Epub 2023 Oct 14.
China has implemented various policies and measures for controlling air pollutants. However, our knowledge of the long-term trends in ambient volatile organic compounds (VOCs) after the implementation of these action plans in China remains limited. To address this, we conducted a five-year analysis (2016-2020) of VOC compositions and concentrations in Beijing. The annual VOC concentration decreased from 44.0 ± 28.8 to 26.2 ± 16.4 ppbv, with alkanes being the most prevalent group. The annual average concentrations of alkenes, alkynes, and aromatics have experienced a significant decrease of over 50 %. Seasonal variations indicated higher VOC concentrations in winter and autumn, with more significant reductions observed in winter and autumn. The impact of meteorological conditions caused variations in VOC reductions during the Chinese Spring Festival. Satellite-based measurements of formaldehyde (HCHO) columns confirmed the reduction of VOC emissions during the Coronavirus (COVID-19) lockdown. The normalized annual average VOC concentration decreased by 2.9ppbv yr from 2016 to 2020, and emission reduction contributed to 58.8 % of VOC reduction from 2016 to 2020 after meteorological normalization, indicating the effectiveness of implemented control measures. Based on receptor model, vehicle emissions and industrial sources were identified as the largest contributors to VOC concentrations. Vehicle emissions, liquefied petroleum gas/natural gas (LPG/NG) use, and coal combustion were major drivers of VOC reduction. Potential source region analysis revealed that air masses transported from northwestern and southern regions significantly contributed to VOC concentrations in Beijing. The range of source regions shrunk in both northwestern and southern regions with the reduction in VOC concentrations. The annual variations of ozone formation potential indicated a significant decrease in VOC reactivities through emission control. These results could provide insights into future emission control and coordinated efforts to improve PM and ozone levels in China.
中国已实施了各种控制空气污染物的政策和措施。然而，在中国实施这些行动计划后，我们对环境挥发性有机化合物（VOCs）长期趋势的了解仍然有限。为解决这一问题，我们对北京的VOCs成分和浓度进行了为期五年（2016 - 2020年）的分析。年度VOC浓度从44.0±28.8 ppbv降至26.2±16.4 ppbv，其中烷烃是最主要的类别。烯烃、炔烃和芳烃的年平均浓度显著下降超过50%。季节变化表明冬季和秋季的VOC浓度较高，且冬季和秋季的降幅更为显著。气象条件的影响导致中国春节期间VOC减排出现变化。基于卫星的甲醛（HCHO）柱测量证实了冠状病毒病（COVID - 19）封锁期间VOC排放的减少。2016年至2020年，归一化年平均VOC浓度每年下降2.9 ppbv，气象归一化后，减排对2016年至2020年VOC减排的贡献率为58.8%，表明已实施的控制措施是有效的。基于受体模型，车辆排放和工业源被确定为VOC浓度的最大贡献者。车辆排放、液化石油气/天然气（LPG/NG）使用和煤炭燃烧是VOC减排的主要驱动因素。潜在源区分析表明，从西北地区和南部地区输送来的气团对北京的VOC浓度有显著贡献。随着VOC浓度的降低，西北地区和南部地区的源区范围均缩小。臭氧生成潜力的年度变化表明，通过排放控制，VOC反应活性显著降低。这些结果可为中国未来的排放控制以及改善PM和臭氧水平的协同努力提供见解。
