| In this thesis, the heavy metal pollution and chemical speciations in the surfacesediments from typical cities(Lanzhou Reach, Yinchuan Reach, Xining Reach, Baotou Reach)in upstream of Yellow River was monitored for Cu、Fe、Mn、Ni、Zn、Cd、Cr and Pb byInductively Coupled Plasma-Atomic Emission mass spectrometry (ICP). The pollutionassessment of heavy metals was used by Geoaccumulation index (Igeo), enrichment factor,pollution load index, a single factor mass index and so on.1. The heavy metal concentration (mg/kg) of Yellow River (Lanzhou Reach) sedimentranged as flowings: Cu,15.52-57.50; Fe,19600.33-48350.00; Mn,493.50-1260.00; Ni,9.34-53.20; Zn,64.86-168.57; Cd,1.09-4.25; Cr,70.00-139.33; and Pb,5.66-19.13in thesurface sediments. The contents of heavy metal were1.1to3.9times higher than that of thesoil background values, respectively.Yellow River (Yinchuan Reach) sediment heavy metal concentration (mg/kg) were: Cu,18.83-28.98; Ni,29.25-53.40; Zn,75.87-89.33; Pb,5.66-15.86; Cd,0.32-4.55; Cr,73.73-111.64; Mn,485.27-674.83; and Fe,21240.00-29143.33in the surface sediments. Thecontents of heavy metal were1.01to1.84times higher than that of the soil background values,respectively.The heavy metal concentration (mg/kg) of Yellow River (Xining Reach) sedimentranged as flowings: Cu,11.86-30.98; Fe,20637.33-32203.33; Mn,431.93-798.03; Ni,20.38-86.11; Zn,67.18-104.61; Cd,0.27-1.33; Cr,87.84-130.33; and Pb,1.21-14.03in thesurface sediments. The contents of heavy metal were1.01to1.43times higher than that of thesoil background values, respectively.Yellow River (Baotou Reach) sediment heavy metal concentration (mg/kg) were: Cu,10.28-32.43; Ni,26.08-48.07; Zn,74.53-121.97; Pb,1.51-10.64; Cd,0.39-1.21; Cr,84.20-147.93; Mn,475.07-722.17; and Fe,18460.00-32975.33in the surface sediments. Thecontents of heavy metal were1.06to4.28times higher than that of the soil background values,respectively.2. The heavy metals Cu, Fe and Mn in the Yellow River (Lanzhou Reach) sedimentshowed a very significant positive correlation (p<0.01), which indicated that three metals mayhave common sources of pollution, but Mn, Pb and Zn could not have common sources ofpollution. The heavy metals Cu, Mn, Fe and Cr in the Yellow River (Xining Reach) sedimentshowed a very significant positive correlation (p<0.01), which indicated that the metals couldhave common sources of pollution, but Zn, Cd and Fe may not have common sources ofpollution. The heavy metals Cu, Fe and Mn in the Yellow River (Yinchuan Reach) sedimentshowed highly significantly positive correlation at99%level. This might imply that elementsCu, Fe and Mn might have a common origin, but Zn, Pb and Ni could not have commonsources of pollution. The heavy metals Fe and Mn、Cu and Zn in the Yellow River (Baotou Reach) sediment showed highly significantly positive correlation at99%level. This mightimply that elements Fe and Mn、Cu and Zn may have a common origin.3. Six kinds of evaluation methods based on total concentration and sequential extractionof heavy metals in sediment were employed to assess the degree of contamination andpotential ecological risk of heavy metals in sedimens from Yellow River (Lanzhou Reach、Xining Reach、Yinchuan Reach and Baotou Reach), The results of comprehensive assessmentindicated that the potential ecological risk and bioavailability of Cr and Cu in Lanzhou Reachwere very high, and had great impact on the local environment. The results of comprehensiveassessment indicated that the potential ecological risk and bioavailability of Cu in XiningReach were very high, and had great impact on the local environment. The results ofcomprehensive assessment indicated that the potential ecological risk and bioavailability ofCd and Cu in Yinchuan Reach were very high, and had great impact on the local environment.The results of comprehensive assessment indicated that the potential ecological risk andbioavailability of Cr、Cu and Pb in Baotou Reach were very high, and had great impact on thelocal environment. |
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