湛江湾表层沉积物重金属分布及污染评价

利用ICP-MS分析测定了湛江湾表层沉积物中Cr、Cu、Zn、Cd、Pb等重金属含量。各站位中Cr、Cu、Zn、Cd和Pb等元素全海湾平均含量分别为(84.84±3.86)×10-6、(29.51±1.44)×10-6、(110.02±10.14)×10-6、(0.205±0.003)×10-6、(56.49±1.31)×10-6。各站位表层沉积物中重金属含量较高及其富集系数较大的区域大多集中在人类活动较频繁的港口、码头等海域,体现了人类活动加速重金属沉积过程的痕迹。相关性分析结果表明,Cr与Cu、Pb、Zn等元素的沉积行为差异较大,可能与其在沉积物中主要赋存形态为氧化态和残渣态,而Zn、Cd和Pb等元素在各相中都有富集有关。与已有结果比较,湛江湾表层沉积物中Cr、Cu、Pb、Zn等引起的污染呈逐渐加重的演变趋势,须采取有效的预防措施。

Distribution and pollution assessment on heavy metals in surface sediments of Zhanjiang Bay

The content of heavy metals(Cu,Pb,Zn,Cd,Cr) in surface sediments of Zhanjiang Bay was analyzed with ICP-MS.Of all 12 stations in Zhanjiang Bay,the average contents of Cr,Cu,Zn,Cd and Pb in surface sediment were(84.84±3.86)×10-6,(29.51±1.44)×10-6,(110.02±10.14)×10-6,(0.205±0.003)×10-6,(56.49±1.31)×10-6,respectively.A similar planar distribution for all metals was observed that the content and accumulation coefficient of each element was higher in anthropogenic area than other areas,which expressed the accelerating sedimentation of metals due to the influence of anthropogenic activity.Compared with other four elements by Pearson correlation analysis,a discordant sediment behavior was observed for Cr due to its main speciation as oxidizable and residual forms in sediment.The pollution situation of Cr,Cu,Pb and Zn in surface sediment became more serious compared with the reference results in Zhanjiang Bay,and some effective measures must be adopted.