汕头湾表层沉积物重金属元素含量和分布特征研究

A study on concentration and distribution characteristics of heavy metals in surface sediment of the Shantou Estuary in China

于2002年9月在汕头湾采集了13个表层沉积物样品,测定了它们的细粒级组分、总有机质、铝、铁、锰、铜、锌、铅、镉、铬、镍、钴的含量,对其分布特征及其彼此之间相关性进行了分析,并以南海陆架区重金属含量为背景值计算了汕头湾表层沉积物重金属元素的富集系数,结果表明,铁、锰、铜、锌、铅、镉、铬、镍、钴的含量范围分别为2.91%-3.94%,427.85-810.96,24.43-79.49,84.83-248.50,35.56-50.25,0.30-1.75,36.11-74.22,16.99-31.69,8.22-10.87 mg/kg,其分布由汕头湾上游的榕江口至湾口呈波浪状递减（锰除外）。汕头湾表层沉积物中各重金属的富集系数均大于1,其中富集系数从大到小的重金属元素是铜、镉、铅、锌、镍、铬和锰。人为排污、水动力作用、黏土含量、盐度是多数重金属元素分布特征的控制因素。锰的分布特征更多地取决于汕头湾水域的氧化还原条件。

Contents of fine grain-size,total organic matter,aluminum,iron,manganese,copper,zinc,lead,cadmium,chromium,nickel and cobalt were determined for 13 surface sediments collected from the Shantou Estuary in Guangdong Province,China in September of 2002,and the relationships of one to another among them and their distributional characteristics were analyzed.Meanwhile,the enrichment factor of some major heavy metals in the surface sediment of Shantou Estuary was calculated according to their background value in the South China Sea.The result suggested that content ranges of iron,manganese,copper,zinc,lead,cadmium,chromium,nickel and cobalt were 2.91%～3.94%,427.85～810.96,24.43～79.49,84.83～248.50,35.56～50.25,0.30～1.75,36.11～74.22,16.99～31.69,8.22～10.87 mg/kg,and their distribution pattern showed a decrease trend as waves from outfall of the Rongjiang River to the mouth of Shantou Estuary（except manganese）.The enrichment factor of each heavy metal were higher than one,and showed an order copper graater than cadmium graater than lead graater than zinc graater than nickel graater than chromium graater than manganese.For most heavy metals,their distribution characteristics were controlled by anthropogenic pollution,hydrodynamic process,clay and salinity.As for the element manganese,redox conditions probably play an important role in controlling distribution pattern.