Shang Lihai

The concentrations and distribution of mercury in aquatic ecosystem of Baihua Reservoir

Mercury species in water column, sediment and fish from the Hg-contaminated Baihua Reservoir were measured by trap pre-concentration and CVAFS and CVAAS detection methods. The results showed that the highest average total Hg concentration is up to 73.36 ng/L in the water column, 186.7 ng/L in pore water of surface sediment in the Baihua Reservoir. The total mercury concentrations in the sediments range from 0.87 to 33.74 mg/kg. This suggests that sediment re-suspending and Hg input from the upstream organochemical plant are the main mercury sources of water body for this reservoir. In addition, the possible reason why mercury is low in fish is that the low DOC and high pH are infavarable to methylmercury formation or absorption by fish.Mercury species in water column, sediment and fish from the Hg-contaminated Baihua Reservoir were measured by trap pre-concentration and CVAFS and CVAAS detection methods. The results showed that the highest average total Hg concentration is up to 73.36 ng/L in the water column, 186.7 ng/L in pore water of surface sediment in the Baihua Reservoir. The total mercury concentrations in the sediments range from 0.87 to 33.74 mg/kg. This suggests that sediment re-suspending and Hg input from the upstream organochemical plant are the main mercury sources of water body for this reservoir. In addition, the possible reason why mercury is low in fish is that the low DOC and high pH are infavarable to methylmercury formation or absorption by fish.

Distribution characteristics of mercury and methylmercury in phytoplankton at Guizhou Plateau reservoirs in winter

To understand the distribution characteristic and bioaccumulation factors(BAF) of total mercury(THg) and methylmercury(MeHg) in phytoplankton at Guizhou Plateau reservoirs,southwest of China.The phytoplankton and water samples were investigated at five reservoirs in the winter of 2012.The results showed that diatom was the dominant algae at Guizhou Plateau reservoirs in winter and phytoplankton abundance had obvious difference at the five reservoirs.The maximum phytoplankton abundance was about 29.05 × 104cells / L at Lake Baihua dam,and the minimum only 0.49 × 104cells / L at Sanbanxi Reservoir.The concentrations of THg and MeHg in phytoplankton were 29.29-277.07 ng / g(dry) and 1.12-10.93 ng / g(dry),respectively.The maximum concentrations of THg and MeHg in phytoplankton was at Lake Baihua.The BAF of THg and MeHg in phytoplankton were 1.42 × 104-9.78 × 104and 3.10 × 104-4.43 × 105,respectively.The maximum BAF in phytoplankton of THg was at Lake Baihua.The maximum BAF of MeHg in phytoplankton was at Lake Hongfeng.There was different effect on biological enrichment of mercury and methylmercury for different phytoplankton species composition.There were significant positive correlations between MeHg in phytoplankton and THg,MeHg,dissolved MeHg(DMeHg) in water.No significant correlation was found between MeHg in phytoplankton and the THg,DMeHg in water.MeHg was not only absorbed by phytoplankton.There were other factors influencing MeHg concentration in phytoplankton inevitably.There were significant negative correlations between MeHg in phytoplankton and environmental factors(SD,TN,NO-3-N).The degree of eutrophication had effects on MeHg concentration in phytoplankton.