济南市大气颗粒汞的浓度特征及污染来源解析

Concentration Characteristics and Source Identification of Atmospheric Particulate Mercury in Jinan

为了解冬季采暖对济南市大气PM_(2.5)中汞浓度的影响,在济南市城郊开展了为期超过两年的PM_(2.5)样品采集工作,共计采集有效样品481个,测定并分析其中的颗粒汞(PHg)浓度和汞含量变化特征。结果表明,济南市大气PHg在采暖期的浓度均值为583.1 pg/m^(3),约为非采暖期的1.4倍,在国内外城市中处于中等偏上水平。济南市大气PM_(2.5)对PHg具有极强的富集能力,且在采暖期更强,可能与燃煤等活动排放了更多的超细颗粒物有关。在采暖期,大气PHg浓度主要受煤炭燃烧源和交通排放源影响,两者分别贡献了总方差的39.2%和16.7%;在非采暖期,气象条件季节性变化、交通排放源、煤炭燃烧源的影响显著,三者分别贡献了总方差的32.4%、15.8%、12.0%。高浓度PHg主要来源于分布在采样站点东北偏东方向上的众多燃煤工业企业。此外,济南市大气PHg还主要受来源于鲁西南地区的区域污染气团的影响,途经污染较重的京津冀地区的污染气团对济南市PHg浓度也有较大贡献。在非采暖期,济南市PHg还受到来自东南和西南方向的清洁海洋气团的显著影响。

To understand the effects of winter heating activities on mercury(Hg)in PM_(2.5)in Jinan,the concentrations of particulate mercury(PHg)in 481 PM_(2.5)samples collected over two years at a suburban site in Jinan were measured,and the variation characteristics of PHg concentration and Hg content in PM_(2.5)were analyzed.The results showed that the average concentration of PHg in Jinan was 583.1 pg/m3 during the heating period,about 1.4 times of that during non-heating period,which was above the mdeium level in domestic and foreign cities.PM_(2.5)in Jinan had a strong enrichment capacity for PHg and this capacity during the heating period was stronger than those during the non-heating period,possibly due to the increased emissions of ultra-fine particles from activities such as coal combustion.During the heating period,coal combustion and traffic emission were the dominant sources of PHg,contributing 39.2%and 16.7%of the total variance respectively,whereas PHg were primarily influenced by meteorological variations,traffic emission and coal combustion during the non-heating period,contributing 32.4%,15.8%and 12.0%of the total variance respectively.The elevated PHg concentrations were mainly attributed to the numerous coal-burning industries located in the east-northeast of the sampling site.In addition,regional transport from the southwestern Shandong Province and the Beijing-Tianjin-Hebei region also contributed to the high PHg levels in Jinan.In contrast,PHg concentrations during the non-heating period were also strongly influenced by the clean ocean air mass from the southeast and southwest.