| A few researches found elevated MeHg concentrations in fish even in lakes located far from point sources in northern Europe and North America. As a result, Mercury contamination of aquatic systems became an important worldwide health concern. As a water supply for the industry,agriculture, living as well as aquiculture in regional drainage area and ZhunYi City, WuJiangdu reservoir is should be concerned for the actual status of mercury pollution . From December in 2006 to August in 2007, the concentration,distribution transportation and fate of mercury species in water columns sediment profiles from WuJiangdu reservoir were measured and researched.Through the detailed studies reported in this thesis, some main conclusions were obtained as follows:1. Discernible seasonal change of different mercury in water body were obtained in WuJiangdu Reservoir. The concentrations of total mercury(HgT) were 0.74-3.34ng·L-1the average isl.38ng·L-1 ; The concentrations dissolved (HgD) ranged from0.49 to2.86 ng·L-1, the average is 1.06ng·L-1 ;The concentrations particulate mercury (HgP) were 0.01- 1.25 ng·L-1 ,the average is 0.33 ng·L-1 ; The concentrations reactive mercury (HgR)were 0.04- 0.62ng·L-1 ,the average is 0.2 ng·L-1. The concentrations total methylmercury (MeHgT)were 0.04- 0.62ng·L-1 ,the average is 0.15 ng·L-1.The concentrations r dissolve methylmercury (MeHgD)were 0.04- 0.62ng·L-1 ,the average is 0.2 ng·L-1. The concentrations particulate methylmercury (MeHgP)were 0.001- 0.88ng·L-1 ,the average is 0.10 ng·L-1.2. The concentrations of dissolve mercury and particulate mercury in WuJiangdu surface freshwater wereevidently correlated with total mercury, it shows that dissolve mercury and particulate mercury are possess on stability characteristic; reactive mercury and dissolve organic carbon were associated with dissolve mercury just in low flow period, it shows that reactive mercury is difficulty to changing methylmercury; The common effects debased the concentrations of available mercury, and reduced the latency harm to hydrophily-zoology.3. The concentrations of total mercury in WuJiangdu sediment which were higher compared to data reported in other uncontaminated lake, total mercury ranges and average concentrations were 126ng.g-1-1202 ng.g-1, 162.5ng.g-1 respectively; which was higher compared to data reported in other uncontaminated lake(1035 ng.g-1 and it shows that WuJiangdu reservoir contaminated in terms of mercury in sediments, the total mercury concentrations were not obvious in terms of space and seasonal variety. Total methylmercury ranges and average concentrations in the whole sediments were 1.58ng.g-1 respectively, the concentrations of methylmercury occurred obviously seasonal variety, higher flux period was higer than low flux period; The methylmercury proportion of mercury was much lower than estuary, peat bog and aha lake and hongfeng lake in the same background area.4. Obviously seasonal changes of total mercury and methylmercury in pore water were obtained during the sampling periods, the concentration of inorganic mercury and methylmercury in high flow period were higher than that in low flow period.The methylmercury in pore water column were evidently correlated to that of the sediment.
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