履约对我国典型城市和偏远背景地区气态单质汞浓度和源区的影响研究

Variations of Concentrations and Potential Source Areas of Gaseous Elemental Mercury at Typical Urban and Remote Sites in China Following the Implementation of Minamata Convention

为了解我国城市和背景地区最新的气态单质汞(gaseous elemental mercury,GEM)水平,比较《关于汞的水俣公约》履约前后这些地区GEM来源和迁移规律的差异,本研究选择了1个城市监测站(淀山湖站)和1个背景监测站(哀牢山站),于2021年分别进行了为期1个月的GEM监测,同时使用潜在源贡献因子计算分析两地GEM的来源,并与履约前的结果进行比对。位于长三角地区的淀山湖站GEM浓度降幅大于位于我国西南的哀牢山站GEM浓度降幅,表明针对我国工业排放源超低排放的改造,获得了显著的履约成效。相对履约前,两地GEM的可能源区和传输形式没有显著改变,人为源排放仍然是影响两地GEM浓度的主要因素。本研究结果表明随着履约工作的逐步推进,我国城市和背景地区的GEM仍有下降的可能,长期在这些站点开展大气汞监测,可以为汞履约成效评估提供有效的数据支撑。

To obtain the latest gaseous elemental mercury(GEM)levels at urban and remote sites in China,and to compare the variations of sources and transports of GEM at those sites after the implementation of Minamata Convention,monitoring of GEM was conducted respectively at an urban site and a remote site in China for one month in 2021.Potential Source Contribution Function analysis was applied for identifying source areas and transports,and the results were compared to those before the convention implementation.The decrease of GEM level at the Dianshanhu urban site was larger than that at the Ailaoshan remote site,suggesting the effectiveness of ultra-low emission technology for convention implementation.The insignificant changes of potential source areas and transports of GEM at both sites indicated that anthropogenic emissions remained the most important impactor.These results imply that GEM in Chinese urban or remote areas can decrease with the gradual progress of the convention implementation,and long-term monitoring of atmospheric Hg in those areas can provide data support for the effectiveness evaluation of the Minamata Convention implementation.