| Continental margin seas are active zones of the land-ocean interaction. Continental shelf sediments take in the metallic elements from land river and atmospheric precipitation. The result of the natural process reveals the natural abundance and distribution of the metallic elements, and constitutes the environmental background value. Under certain conditions, the metallic elements emitted into water by human activities can enter the sediments in relatively unstable chemical forms by a variety of physical and chemical effects. The proportion of different forms extracted by sequential extraction can show the biotoxity, source and migration law of heavy metals, which is significant to study nearshore environment and both temporal and spatial changes of biological production. In this thesis, the content of major components of surface sediments and the content and proportion of heavy metals in non-residual part, collected from the South Yellow Sea (SYS) in Januray and November 2007 and from the East China Sea (ECS) in June 2007, are measured by sequential extraction to discuss the migration law of heavy metals in sediments. Through the comparative analysis of the content and proportion each form of heavy metals in the major components and non-residual part of sediment core, collected from coastal mud off the South Yellow Sea (SYS) in January 2007, the interannual change, the interrelationship and the response to environmental factors of the major components are clarified. Conclusions are summarized as follows:1. The content of Cu in the non-resdual form in mud sediment area in ECS ranges from 1.3μg/g ~ 7.0μg/g, and Fe from 0.91 mg/g ~ 2.5 mg/g, both of which mainly exist in ERO (easily reducible oxides). The content of Pb in the non-resdual form ranges from 5.6μg/g ~ 12.0μg/g, and Mn from 0.07 mg/g ~ 0.26 mg/g, both of which mainly bound to CRAB (carbonate). The content of Al in the non-resdual form is 0.63 mg/g ~ 1.8 mg/g, whose main form is OSM (organic/sulfide matter). The chemical forms of heavy metals and their distributed pattern are influenced by the major component, such as CaCO3, the FeOOH-MnO2 and organic matter. The depth of the sampling station is also a factor correlated to content and chemical forms of the heavy metals and indicates the terrigenous input and the migration behavior in the coastal area.2. The content of CaCO3, FeOOH-MnO2 and OC in 03 profile in SYS ranges from 0.94 % ~ 9.9 %, 0.72 mg/g ~ 1.9 mg/g and 0.15 % ~ 1.5 % respectively, which will change regularly along with the distance from the coast and the grain size. Except the Pb in nearshore station is mainly exist in ERO, other heavy metals and the Pb in the middle station of the SYS are familiar with that in ECS. Grain size and atmospheric precipitation may be the major factors that affect the content of heavy metals. Compared with the forms of heavy metals in the sediments in Yellow River and the ECS, it shows that the nerashore sediment of SYS is mutiple-source from the Yellow River and the ECS. The biogenic source also contributes to the mud area, but is unconspicuous.3. The CaCO3 content has no distinct change trend vertically,ranging from 2.3% ~ 3.3%, with average 2.7 % in sediment core 0306,changed with the runoff amount and sediment load of Huang River. The sedimentation of FeOOH-MnO2 is in a stable state with average 0.73 mg/g, and the content of OC is a little higher than that of other data, ranging from 0.86% ~ 1.2%, with average of 1.0%. Cu is mainly bound to ERO and Pb is CARB. The total content of heavy metals Cu, Pb, Al and Fe in non-residual form investigated in this paper gradually increases vertically, reflecting the environmental change in this sea area in recent 50 year.
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