新冠肺炎疫情期间湖北省大气污染物减排效果评估

Emission Reductions and Air Quality Improvements during the COVID-19 Pandemic in Hubei Province

新冠肺炎疫情期间,湖北省工业源、移动源、扬尘源等人为源排放的大气污染物大幅削减。为了科学评估疫情期间空气质量改善与污染物减排关系,根据烟气连续排放连续监测系统(CEMS)数据计算得到,疫情管控期间,湖北省重点行业二氧化硫(SO2)、氮氧化物(NOx)和烟尘(PM)日均排放量分别为6.8、35.4和80.3 t/d,较管控前下降41.9%、34.7%和47.6%,其中电力、水泥、化工、陶瓷行业排放下降幅度较大。武汉市重点行业PM、SO2和NOx日均排放量较疫情管控前下降18.3%、23.2%、21.7%。通过空气质量模拟量化了气象条件变化及污染减排对环境空气质量改善的贡献,发现疫情期间武汉市PM2.5浓度的下降均为污染减排贡献,气象条件反而会加剧PM2.5污染;疫情期间臭氧浓度有所上升,其中污染减排对臭氧平均浓度上升的贡献占比为52.5%,气象条件的贡献占比为47.5%。

Affected by the COVID-19,the air pollutant emissions from industry,transportation,dust,and other anthropogenic sources were considerably reduced in Hubei Province.In order to estimate the emission reductions and air quality improvements,the CEMS data was used to calculate SO2,NOx,PM emissions from key industries.During the COVID-19 pandemic,daily average emissions of SO2,NOx,PM were 6.8 t/d,35.4 t/d and 80.3 t/d,which decreased by 41.9%,34.7%and 47.6%respectively,compared to the emissions before the COVID-19 lockdown.Emissions from power,cement,chemical,and ceramic plants had larger declines than the other industries.For Wuhan City,daily average emissions of SO2,NOx,PM from key industries were decreased by 18.3%,23.2%,21.7%respectively.The contribution of meteorological conditions and emission reductions to the improvement of ambient air quality was quantified by air quality simulation.Results showed that the decrease of PM2.5 concentration in Wuhan was totally contributed by emission reductions and changes of meteorological condition would intensify PM2.5 pollution.The increase of ozone concentration was the result of the joint action of meteorological conditions and precursor emission reductions,to which the constitution of the former factor was 47.5%and the latter was 52.5%.