School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
Ecotoxicol Environ Saf. 2020 Jun 15;196:110541. doi: 10.1016/j.ecoenv.2020.110541. Epub 2020 Apr 2.
Urban emissions are a major contributor to atmospheric Hg budgets. Continuous measurements of total gaseous mercury (TGM) and particulate-bound mercury (PHg) in PM were conducted from October 2015 to July 2016 in a metropolis, Jinan, in eastern China. Average TGM and PHg concentrations were 4.91 ± 3.66 ng m and 451.9 ± 433.4 pg m, respectively, in the entire study period. During the winter heating period (HP), mean concentrations of TGM and PHg were 5.79 ng m and 598.7 pg m, respectively, twice higher than those during the non-heating periods (NHPs). During the HP, TGM exhibited a distinct diurnal pattern with a peak in the morning and a minimum in the afternoon on less polluted days but a singular peak at midday on heavily polluted days. The diurnal variation of TGM during the NHPs was predominantly influenced by the variation in boundary layer height while during the HP by anthropogenic emissions. The ratio of PHg/PM in Jinan was one to two orders of magnitude larger than those elsewhere worldwide and those in soil and coal, which suggested the high enrichment of PHg in PM in Jinan. Correlation and principle component analysis results suggested that PHg and TGM had common combustion sources during the HP, whereas PHg resulted mainly from biomass burning and meteorological variations during the NHPs. High Hg concentrations in Jinan were mostly caused by emissions from coal-fired power plants, especially for those situated east of the sampling site. In addition, TGM and PHg concentrations significantly increased during haze and fog episodes, but decreased during a dust episode due possibly to strong ventilation conditions combined with partitioning of Hg between adsorption to PM and coarse dust particles.
城市排放是大气汞预算的主要贡献者。2015 年 10 月至 2016 年 7 月，在中国东部的大都市济南连续测量了 PM 中总气态汞（TGM）和颗粒态汞（PHg）。在整个研究期间，TGM 和 PHg 的平均浓度分别为 4.91±3.66ng/m 和 451.9±433.4pg/m。在冬季供暖期（HP），TGM 和 PHg 的平均浓度分别为 5.79ng/m 和 598.7pg/m，是非供暖期（NHPs）的两倍。在 HP 期间，TGM 表现出明显的日变化模式，在污染较轻的日子里，早上有峰值，下午有最小值，但在污染严重的日子里，中午有一个单一的峰值。在 NHPs 期间，TGM 的日变化主要受边界层高度变化的影响，而在 HP 期间则受人为排放的影响。济南的 PHg/PM 比值比世界其他地区以及土壤和煤炭中的比值高出一到两个数量级，这表明济南 PM 中 PHg 的高度富集。相关性和主成分分析结果表明，在 HP 期间，PHg 和 TGM 具有共同的燃烧源，而在 NHPs 期间，PHg 主要来自生物质燃烧和气象变化。济南高汞浓度主要是由燃煤电厂排放引起的，特别是位于采样点东侧的电厂。此外，TGM 和 PHg 浓度在雾霾和雾天显著增加，但在沙尘天气下减少，可能是由于强通风条件和 Hg 在 PM 与粗颗粒之间的分配。
