渤海东部和黄海北部沉积物中重金属分布特征

通过对渤海东部及黄海北部海域138个站位沉积物样品的重金属等含量分析,研究了该海域沉积物重金属元素分布特征及其控制因素.渤海东部及黄海北部海域沉积物中As、Cu、Cd、Cr、Co、Hg、Ni、Pb、V、Zn的平均含量分别为:9.87,20.1,0.15,58.9,11.6,0.02,26.7,23.0,74.0,65.5μg/g;重金属元素Cu、V、Cr、Co、Ni、Zn含量与有机碳含量、小于63μm细粒沉积物呈显著正相关,其在表层沉积物中的分布明显受到有机质含量和沉积物粒径的控制,而As、Hg分布没有明显受到有机质含量和沉积物粒径的影响.富集系数显示, Cr、Co、Ni、Pb、V和Zn为无富集;Cu为轻度富集;As、Cd和Hg为中度富集;依据Q-型聚类分析特征,将研究区域沉积物划分为3个不同的重金属分区,Ⅰ类区沉积物Hg富集程度较高;Ⅱ类区沉积物As富集程度较高;Ⅲ类区重金属元素含量普遍较高,尤其Cu、Zn和Cd含量明显增高.

Distribution of heavy metals in surface sediments in the eastern Bohai Sea and the northern Yellow Sea

Based on the concentration of As, Cu, Cd, Cr, Co, Hg, Ni, Pb, V and Zn in sediment samples taken from 138 stations in Eastern Bohai Sea and Northern Yellow Sea, the distribution characteristics and controlling factors of heavy metals in marine sediment were studied. The average concentration of As, Cu, Cd, Cr, Co, Hg, Ni, Pb, V and Zn were 9.87, 20.1, 0.15, 58.9, 11.6, 0.02, 26.7, 23.0, 74.0 and 65.5 μg/g, respectively. Contents of Cu, V, Cr, Co, Ni and Zn showed a significantly positive correlation between organic carbon contents and the amount of fine-grained sediments (<63 μm) and its distribution in surface sediments was controlled obviously by the contents of organic matters and sediment grain sizes while As and Hg distribution was not significantly affected by the contents of organic matters and particle sizes of sediment. Enrichment factors (EF) were calculated to determine whether the observed concentration was higher than background levels. Three groups of elements: (1) Cr, Co, Ni, Pb, V and Zn were at background concentrations; (2) Cu was slightly enriched; and (3) As, Cd and Hg were moderately enriched. According to the Q-type cluster analysis, characteristics of the sediment in the study area could be divided into three different zones of heavy metal distribution. Class Ⅰ featured high Hg enriched sediment; As of Class II region was higher degree of enrichment; Class III region was higher for all heavy metal elements, especially Cu, Zn and Cd.