The Research On The Pollution Of Heavy Metals In The TaiyuRiver Sediments, Tong'guan Goldfield

The samples of Taiyu river sediments were comprehensively collected and the Hg,Pb,Cd,Cr,As,Cu,Zn were determined. Using Excel as the tool of data processing, the spatial distributions of heavy metals were investigated in Taiyu river sediments. Combined with the reference values of heavy metals of river sediments in study area, the pollution level and present situation about accumulation of heavy metals were evaluated systematically by Nemero Index in Taiyu river. Under the condition of the highest environmental background values of normal granular sediments before modern industrialization, the damage degree of ecological environment by heavy metals were analyzed with potential ecological risk assessment in Taiyu river. The investigations on the vertical occurrence, migration, the adsorption capacity of sediments in the different sediments horizons of heavy metals were developed in Taiyu reservoir, and the changes on strength of mining activities after gold deposits were inversed. The achievements obtained were as follows.(1) The main pollution sources of stream sediments in and out mountain area were analyzed in Taiyu river.(2) Pb and Zn were main heavy metals of stream sediments in Taiyu, and influenced Huanghe river.(3) The homologies among the Hg-Pb, Hg-Cd, Hg-Zn, Cd-Pb, Cd-Zn, Zn-Pb were higher, while Zn, Cd and Cu had homologies in the sediments of Taiyu river. Cr and As accumulated particularly.(4) In the stream sediments of Tongguan goldfield, Pb, Cr and Zn were obviously enriched, Hg and As were slightly enriched, which basically reflected the original geochemistry background values. The concentration of Cd and Cu were relatively low.(5) The heavy metals were over standard except As and Cr, Hg, Pb and Cd were main pollutants in the sediments of Taiyu river.(6) The stream sediments were a record of history about gold mining activities at Tongguan that objectively reflected the low tide and climax of development of gold mining. Except Cr and As, accumulated pollution times of heavy metals in the sediments of reservoir was higher in the whole sections, and the accumulated degree is obvious.(7) The three kinds of heavy metals including Hg, Pb and Cd disserved the ecosystem badly. The damage degree of ecosystem by Cu was strong. Potential ecological risk by Cr, As and Zn were slight. The problems of ecosystem were compound disserved by Hg, Pb and Cd.