湖南省2021年春节期间PM2.5重污染特征及来源分析

Analysis on the Characteristics and Source of Heavy Pollution Process of PM_(2.5) during the Spring Festival in 2021 in Hunan Province

针对2021年春节期间(2月11—17日)湖南省发生的一次PM2.5重污染过程,利用湖南省内组分站和复合监测站水溶性离子分析仪、碳组分分析仪、无机元素分析仪等分析了PM2.5的化学组成,对颗粒物主要成分进行了来源解析,并结合气象综合分析了此次重污染的过程和成因。监测结果显示,此次重污染过程中PM2.5最高日均质量浓度达184μg/m3,超标1.45倍;烟花爆竹集中燃放期间,全省PM2.5浓度平均升高了2.3倍,各城市PM2.5小时峰值浓度较初始浓度分别增高2.7~11.2倍。重污染期间硫酸盐是PM2.5的主要组分,最高可达24.8%;此次重污染是受烟花爆竹燃放叠加高湿静稳、逆温、小风等不利气象条件的影响而引起空气质量的恶化。

A heavy pollution process of PM2.5 occurred in Hunan Province during the Spring Festival from February 11 to 17,2021,was analyzed by using component stations and the ambient air composite monitoring station’s water-soluble ion analyzer,carbon component analyzer,inorganic element analyzer,etc. Combined with meteorological elements,the process and causes of the heavy pollution were analyzed. The monitoring results showed that the maximum daily average mass concentration of PM2.5 in the heavy pollution process was 184 μg/m3,which exceeded the standard by 1.45 times;The PM2.5 concentration in the whole province increased by 2.3 times,and the peak concentration of PM2.5 in each city increased by 2.7 ~ 11.2 times compared with the initial concentration. Sulfate was the main component of PM2.5 during the heavy pollution period,with the maximum concentration up to 24.8%. This heavy pollution is due to the deterioration of air quality caused by the superposition of fireworks and adverse meteorological conditions such as high humidity,static stability,temperature inversion and thin wind.