大沽河口潮间带沉积物重金属污染特征

为了解胶州湾大沽河口潮间带沉积物重金属污染现状，2015年采集60个大沽河口潮间带表层沉积物样和2个柱状样，测试了样品的粒径及主要重金属元素含量。结果显示，大沽河口地区以黏土质粉砂为主，局部含有砂质粉砂和粉砂质砂；潮汐对粒径较大的砂、粉砂的分选性较好，对黏土的分选性较差；沉积物重金属污染程度较低，Zn、Pb、Cu、Cr、Cd、As和Hg等7种重金属元素的平均含量为30.29×10-6、29.35×10-6、80.55×10-6、69.92×10-6、0.08×10-6、0.05×10-6和8.63×10-6；表层沉积物中各金属元素与平均粒径之间有较强的负相关性；利用Hakanson潜在生态危害指数法对各金属元素的潜在生态危害程度进行了评价，结果显示大沽河口潮间带重金属污染程度整体较低，Hg为主要超标元素，近年来，该地区环境有所改善。

The characteristics of heavy metal pollution in the intertidal zone of Dagu estuary

60 surface sediment samples and 2 cylindrical samples were collected from intertidal zone of Dagu estuary, Jiaozhou bay in May 2015, the particle size and concentrations of main heavy metals were measured.The distribution of sand and silty sand were better, and the separation of clay was poor.The concentrations of heavy metals were generally low in this survey, in which the average concentrations of Zn, Pb, Cu, Cr, Cd, As and Hg were 30.29×10-6, 29.35×10-6, 80.55×10-6, 69.92×10-6, 0.08×10-6, 0.05×10-6 and 8.63×10-6, respectively.There was a strong negative correlation between the metallic elements in the surface sediments and the average particle size.The potential ecological risks of heavy metals were evaluated by Hakanson's method.The results displayed that almost all the metals were at low pollution levels except Hg.The environment has improved in recent years.