Concentrations and Species Distributions of Mercury in Water and Sediment Porewater of Puding Reservoir,Guizhou Province

In order to study geochemistry circle of mercury in Puding Reservoir,the concentrations and distributions of various mercury(Hg) species,including total Hg(THg),dissolved Hg(DHg),reactive Hg(RHg),particulate Hg(PHg),total methylmercury(TMeHg),dissolved methylmercury(DMeHg),and particulate methylmercury(PMeHg) in the columns of water body and sediment porewater of Puding Reservoir,were determined by distillation-ethylation(GC-CVAFS) technique.The concentrations of THg,RHg,and TMeHg in the water columns ranged from 1.29 to 3.18 ng/L,from 0.09 to 0.43 ng/L,and from 0.06 to 0.18 ng/L,respectively.The concentrations of DHg and DMeHg in the porewater of sediment ranged from 2.65 to 11.47 ng/L and from 0.06 to 1.16 ng/L,respectively.Particulate Hg,which accounted for 46% of THg,was significantly correlated with THg;PMeHg,which accounted for 37% of TMeHg,was positively correlated to TMeHg;and the distributions of MeHgT were controlled by DMeHg.Moreover,the concentrations of DHg and DMeHg in porewater were higher than those in the water at interface,which suggested that sediment was the dominant Hg source to the reservoir.