渤海湾海岸带表层沉积物中黑碳的分布特征

在渤海湾西海岸潮间带、近海和主要河流采集了85个表层沉积物样品,对黑碳（BC）的质量分数及其分布规律进行了研究,并探讨了BC与沉积物粒度的关系。结果表明：（1）渤海湾海岸带表层沉积物中BC的平均质量分数为（0.65±0.42）mg·g^-1,占总有机碳的比例为16.8%±7.5%,均高于我国其它海岸带;（2）潮间带沉积物中BC的质量分数存在明显的南北分区差异（以天津港码头为界）,北区（0.92mg·g^-1）比南区（0.22mg·g^-1）平均高4倍以上;近海和河流样品BC的质量分数也有一定程度的＂北高南低＂趋势,表明BC在海岸带运移扩散的继承性,河流输入可能是主要途径;（3）潮间带沉积物粒度表现为＂北区细＂（以粘土质粉砂主）而＂南区粗＂（以砂为主）,反映两个区域的水动力条件和沉积环境不同,是造成BC质量分数区域差异的主要原因。

The distribution of black carbon in the surface sediments of coastal zone,Bohai Bay

The concentration and spatial distribution of black carbon（BC）in west coast of Bohai Bay were investigated,based on 85 samples that collected from the intertidal zone,near shore and main rivers.The correlation between BC concentration and sediment granularity was analyzed and discussed.The results showed that（1）mean concentration of BC in coastal zone of Bohai Bay was（0.65±0.42）mg·g^-1,which contributed 16.8%±7.5% of total organic carbon.These data were higher than the other coastal areas of China;（2）significant difference of BC concentration was observed between the southern and northern areas（divided by Tianjin Port）,and the average BC concentration in the northern area（0.92 mg·g^-1）was higher than that in the southern area（0.22 mg·g^-1）by more than four folds;BC concentrations displayed little spatial difference between near shore and rivers,which indicated the consistency of BC transportation in coastal zone and river input may be the main source;（3）sediment granularity in intertidal zone showed the obvious difference of ＂fine in north＂（dominated by clayey-silt）and ＂coarse in south＂（dominated by sandy）,which illustrated the different sedimentary dynamics between two areas,and it explained the spatial difference of BC concentrations.