Abstract:
Distributions of reactive and dissolved gaseous mercury and controlling factors were investigated in Hongfeng Reservoir based on gold trap and cold vapour atomic fluorescence detection. Dissolved gaseous mercury (DGM) concentrations changed from 0.024 to 0.110 ng/L. DGM concentrations were higher in summer than in winter, and decreased with increasing water depth. The vertical and seasonal distribution patterns of DGM showed the photoreduction of Hg (Ⅱ) complexes served as a major source of Hg
0 production in water. DGM concentrations were also affected by algae activities, but were not related with temperature and dissolved carbon. RHg concentrations changed from 0.14 to 2.70 ng/L and were mainly controlled by photoreduction and methylation of Hg
2+, as well as mercury contaminations.