BACKGROUND VALUES OF METAL ELEMENTS IN RIVER SEDIMENTS WITHIN THE BEIJING AREA
北京地区河流沉积物的金属元素背景值研究

The research on background values of metals in the river sediments is a basic work for the impact assessment In the aquatic system.Total Cu, Ph., Zn, Cd, Ti, Fe, Ma, Ni, Ca, Cr, Hg were extracted bydigesting 1 - 2 gram of air-dry sediments in aqua regia-HP-HCIO4, HNO3-H2SO4-HF, HNO3,H2SO4-V2O5and analyzed by the flameless atomic absorptionCWFD-1/2) and atomic absorption flame emissio-spectrophotometer (A-A-640B) and cold atomic absorption (CG-) .In this paper, D the numbers of necessary samples of Cu, Pb, Zn, Cd, Gr, Hg in river sediments of the area for a given level of statistical certainty were computed. 2 ) The distribution types of background values of metals were determined by vestelivs statistic method, the background values of metals in the river sediments were computed.3)The eocrelation coefficients and step-wise regression and factor analysis on the chemical composition data in the sediments were performed by a computer.The correlation between the metals was discussed. 4 ) Background contents of metals in river sediments were compared with those in rocks and soils in this afea.The results showed the background values of metals in river sediments in the area are in normal rangea.The distribution of backvaluea and correlation and translation of the petals in this area are dominantly effected by regional geology and hydrogenetic geochemistry.