Primary Study On Pollution Of Heavy Metals And Biogenic Elements In Typical Sea Areas Of The North Yellow Sea

In July2009acquisition of Zhifu Bay and Jiaozhou Bay surface sediment samplesand columnar sediment samples were measured and analyzed heavy metalconcentrations of sediment mercury (Hg), copper (Cu), lead (Pb), zinc (Zn), cadmium(Cd), nickel (Ni), cobalt(Co), manganese (Mn) and biogenic elements in biogenicsilica (of BSi), organic carbon (TOC), total nitrogen (TN), total phosphorus (TP)content, then analysis and evaluate the potential ecological risk of heavy metals andbiological elements of hazard.Compared with other domestic waters and harbour, heavy metals of Zhifu Bay andJiaozhou Bay have a relatively low level of Hg, Cu, Pb, Zn, of Cd, Ni, Co., Mn,average content of them were lower than the quality standards of the National Marinesediments Class Ⅰ,the average content of0.015mg/kg12.3mg/kg,12.3mg/kg,32.8mg/kg,8.67mg/kg,11.4mg/kg,5.00mg/kg of the229mg/kg well as0.03mg/kg,19.02mg/kg,12.92mg/kg53.06mg/kg,0.055mg/kg,17.21mg/kg,8.24mg/kg,800mg/kg.Geological Cumulative Index Method and the Potential Ecological RiskIndex Assessment show that Hg in the two bays is relatively serious pollution heavymetal, in addition, Zhifu Bay of Cd in the moderate hazard.Columnar sediment sample analysis found that the trends of most heavy metalswere tested emerged from the bottom to the surface gradually increased of ZhiFu Bayand Jiaozhou Bay, the vertical distribution of heavy metals Zhifu Bay showingobvious serrated, Hg, Cu, Pb, Zn, Co.values appear in the10~15cm department,appeared in the1990s, and heavy metals in sediments of JiaoZhou Bay region of30~40cm out fluctuations is earlier.The content of biogenic elements of of BSi, the TP, the TOC, TN in ZhiFu Bay andJiaoZhou Bay sediments at a high level,their contents were1.44%~2.61%,0.052%~0.1%,0.28%~0.91%,0.01%~0.05%and1.82%~3.47%,0.028%~0.052%,0.62%~0.96%,0.05%~0.08%, with an average1.98%,0.07%,0.65%,0.03%and2.47%,0.042%,0.75%,0.63%. BSi contents from the two harbour higher than mostof the other Chinese waters, TOC, TP, are Ⅰgrade pollution. TN of Zhifu Bay is alsoat the Ⅰ level pollution, the majority ofthe Jiaozhou Bay stations TN in the level ofclass II pollution.From the molar ratio of BSi/TOC, in the waters far from shore inZhifu Bay the diatom contribution to the TOC larger, but Jiaozhou Bay in the coastal waters, this consistent with the two bays in the past diatom red tide waters. From theTN/TP ratio ZhiFu Bay and JiaoZhou Bay surface sediments belong to the P limit.With the increase of land-based sources of N input, P limit trend of ZhiFu Bay andJiaoZhou Bay will further. From the TOC/TN ratios, ZhiFu Bay surface sediments,TOC mainly by the impact of land-based sources,and TOC in Jiaozhou Bay surfacesediments are subject to the mixed effects of the aquatic and terrestrial sources.Biogenic elements of ZhiFu Bay sediments do not significantly increase with depthincrease, but content of biogenic elements of JiaoZhou Bay sediment have adecreasing trend with the increase of depth. The start time of nutrition enter inJiaoZhou Bay Area much earlier (around1960) than ZhiFu Bay region (1995~1996).