来自汞污染场地气态汞的排放是全球大气汞重要的源。许多污水灌溉区的土壤长期受到含汞污水的影响，是一种典型的汞污染场地。我国拥有世界上面积最大的污灌区。由于受技术、管理和成本等方面的制约，我国污灌区土壤汞污染情况非常严重，来自我国污灌区土壤的汞排放可能影响区域汞循环。但目前针对我国污灌区土壤气态汞排放研究还几乎为空白。本项目拟在我国典型污灌区利用动态通量箱，开展污灌区土壤气态排放的现场观测研究，认识污灌区土壤气态汞的排放通量和变化特征。结合实验室模拟研究，认识影响污灌区土壤气态汞排放的重要因子，进一步构建一个适用于污灌区土壤气态汞排放的参数化方案。最终，在上述参数化方案的基础上，结合现场调查、数据收集和地理信息系统，初步评估我国污灌区土壤气态汞的排放通量及其时空变化特征，为深入认识污灌区在区域乃至全球汞循环中的作用提供科学依据。

Mercury (Hg) emission from Hg-polluted region has an important contribution to the atmospheric Hg pool. Sewage irrigation region is one of the typical areas for Hg pollution after long-term irrigation with Hg-polluted sewage. China has the largest area of sewage irrigation in the world. Because of the limitation of technology, management and cost, Hg pollution in the soil of sewage irrigation is very serious in China. Hg emission from this region potentially influences the regional Hg cycle. However, few studies have been carried out to address this issue. In this project, we will conduct field measurements to investigate the Hg emission from sewage irrigated soil using dynamic flux chamber. Meanwhile, we will perform the laboratory simulations to explore the key factors influencing the Hg emissiion and further to develop a parameterization of Hg emission for the sewage irrigated soil. Finally, we will use this parameterization together with field survey, data collection and geographic information system (GIS) to estimate the Hg emission flux from sewage irrigation soil in China. This study will significantly promote the understanding of the role of the sewage irrigation region in the regional and global Hg cycle.