大气污染综合治理攻坚行动前后北京市PM2.5质量浓度变化特征研究

Study on variation characteristics of PM2.5 mass concentrations in Beijing after the action on comprehensive control of air pollution

基于2013—2017年北京市美国大使馆监测点PM2.5质量浓度数据,分析了北京市近5年来PM2.5质量浓度的变化特征及其与NO2和SO2的关系,重点讨论了2017年秋冬季针对控制散煤燃烧排放实施的以'煤改气''煤改电'及'错峰生产'等为主的大气污染综合治理攻坚行动后北京市PM2.5变化。结果表明,北京市PM2.5质量浓度年均值自2013年起呈现逐年降低的趋势,2017年的年均值较2013年降幅达到50%。2013—2016年间,不同季节PM2.5质量浓度表现为冬季>秋季>春季>夏季的规律。2017年攻坚行动实施后,冬季PM2.5质量浓度明显低于秋季和春季,接近于夏季水平;冬季大气SO2和NO2的质量浓度相对于往年亦有大幅度降低,其中SO2的质量浓度降幅更为明显,表明散煤燃烧排放得到较明显的控制。PM2.5质量浓度与SO2均存在显著的正相关性,表明'煤改气''煤改电'等禁止散煤燃烧政策对降低PM2.5具有明显效果。

Based on the data of the PM2.5 mass concentrations from the monitoring point at the US embassy in Beijing from 2013 to 2017,the characteristics of PM2.5 mass concentration and its correlation with the mass concentrations of NO2 and SO2 in Beijing in the past five years are analyzed.The emphasis is focused on the variation characteristics of PM2.5 after the action on comprehensive control of air pollution implemented in the autumn and winter of 2017,which is aimed at the emission reduction from banning of uncontrolled coal combustion.The results show that the annual average of PM2.5 mass concentration in Beijing has decreased yearly since 2013,and the decreasing range of the annual average in 2017 has reached 50%.Analysis of data in different seasons shows that the PM2.5 mass concentration in winter is the highest,followed by autumn,spring,summer in descending order in 2013 to 2016.However,after the action on comprehensive control of air pollution,it is noticed that the mass concentration of PM2.5 in winter 2017 was lower than that in autumn and spring,approaching the level of summer.In addition,compared with the past years,the mass concentrations of NO2 and SO2 in the air also decreased significantly in winter 2017,in which the decrease of SO2 mass concentration is more obvious.These results show that the emission from burning coals has been effectively controlled after the action on comprehensive control of air pollution.Finally,the correlation analysis shows that the mass concentrations of PM2.5 has a significant positive correlation with those of SO2,indicating that countermeasures for the banning of uncontrolled coal combustion such as'coals replaced by gas'and'coals replaced by electricity'have an obvious effect on reducing the PM2.5 emission.