Concentration Characteristics and Source Identification of Atmospheric Particulate Mercury in Jinan
To understand the effects of winter heating activities on mercury(Hg)in PM2.5 in Jinan,the concentrations of particulate mercury(PHg)in 481 PM2.5 samples collected over two years at a suburban site in Jinan were measured,and the variation characteristics of PHg concentration and Hg content in PM2.5 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.PM2.5 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.