The results of the suspended material measurement in the Huanghe River Estuary show that the silt movement in the estuary is different during summer and winter. The centric water-mass in Bohai Sea enters the Laizhou Bay, which makes the fresh water occupy the head of Laizhou Bay and prevents the silt from spveading to the sea.The disturbing of wind in winter makes the sediment resuspend which results in the high content of suspended materials in the water. The distribution of suspended materials and salinity in summer indicate that because of its own momentum, the silt from the Huanghe River will go ahead out of the river mouth and the effect of centric water-mass in the middle Bohai Sea is relatively small in summer. The distributions of suspended materials in the mid and bottom layer water during different seasons show that the primary direction of the siltl movement in the estuary is towards NE, whice coincides with the movement of residual current.Our paper also presents the size distribution of suspended materials.According to the data, we consider that the silt from Huanghe River moves mainly in the surface layer and the Huanghe River Estuary belongs to weak mixing estuary.
Heavy metals (Cu, Pb, Zn, Mn, Fe, Cr, Ni) in the sediment from Huanghe River Estuary and the adjacent areas were analyzed using Model WFX-IA AAS. The eoneentrationsof these elements are: Cu 9-32ppm,Pb 24-44ppm,Zn 41-105ppm, Mn 500-700ppm, Fe 2.1-3.0%, Cr 50-71ppm, Ni 24-72ppm. There are relatively close correlations among the distribution of the heavy metals, suspended materials and salinity. The distribution of heavy metals in summer are similar to that in winter, except Pb. It is believed that the higher concentration results from the increasing of water discharge,silt content and the decreasing of particle size in the summer. Pb is easily absorbed and carried in the suspended materials,which, perhaps, is another reason that the concentration of Pb is higher in summer.
Ten samples from the Huanghe River Estuary were analysed to separate the heavy metals (Cu, Pb, Zn, Cr, Ni, Fe, Mn, Cd) into following phases: (1) adsorbed to materials, (2) bound to carbonates, (3) Fe-Mn oxides, (4) organic matters, (5) residual. The contents of the heavy metals in residue fraction account to the main part of the total concentrations. The concentrations of the heavy metals adsorbed on the materials are very low, and the heavy metals bound to Fe-Mn oxides are relatively stable, making up 10-20 percent of the t otal concentrations, which indicates that there is almost no heavy metal pollution in the estuary. The content of Pb, Mn bound to carbonates are rather high, Pb makes up 18-42 percent, Mn 22-63 percent of the total concentration, which are caused by geological process and coincide with the high content of carbonates in the loess. Cu is concentrated in organic matter indicating the strong complexation abilily of copper with organic matter. The distribution of all the eight elements are not all the same. The order of their progressive decreasing are written as follows: (1) Cu, Cr, Hi, Fe, Zn: Ⅴ>Ⅳ≥Ⅲ>Ⅱ>Ⅰ; (2) Pb, Cd: Ⅴ>Ⅱ>Ⅲ≥Ⅳ Ⅰ;(3) Mn:Ⅱ>Ⅴ>Ⅲ>Ⅳ>Ⅰ.
