春、夏季长江口海域表层沉积物中重金属污染的模糊综合评价及来源分析

Fuzzy comprehensive evaluation and analysis of source of heavy metals pollution in surface sediments from Changjiang Estuary in spring and summer

通过2010年春季(5月)和夏季(8月)对长江口海域表层沉积物中重金属Cu、Zn、Pb、Cd、Hg、As含量的调查分析,应用模糊综合评价方法对表层沉积物中重金属元素的污染程度进行了评价,同时应用主成分分析方法分析了重金属来源。结果表明:春、夏季各重金属平均含量顺序依次均为Zn>Pb>Cu>As>Cd>Hg;仅在夏季有1个调查站位表层沉积物中重金属质量水平属于二类,其余各调查站位在春、夏季表层沉积物中重金属质量水平均属于一类,整体上,春季表层沉积物中重金属污染程度小于夏季;主成分分析的结果表明前2个主成分特征值均大于1,方差贡献分别为43.47%、33.31%,重金属分布主要受工业排污与生活污水、沉积物中有机质、地球化学成分的变化的影响。

The concentrations of six heavy metals were detected in the surface sediments from the Changjiang Estuary during spring（ May） and summer（ Aug.）,2010. The fuzzy comprehensive evaluation model was employed to evaluate the quality status of heavy metals. The principal component analysis（ PCA） was applied to estimate the sources of heavy metal. The results show that the order of average concentration of heavy metals was Zn〉Pb〉Cu〉As〉Cd〉Hg. The quality of heavy metals in surface sediments belongs to the second- class quality in just one sampling station in summer,and the others belong to the first- class quality in all of the sampling stations in spring and summer. Overall,the quality of heavy metals in surface sediments in spring was better than in summer. The contamination sources of heavy metals through the principal component analysis（ PCA） were revealed that the contribution rates of the top two principal components were 43. 47%,33. 31%,respectively. The main sources of heavy metals were as follows： the industrial waste water and domestic sewerage,the change of organic matter and geochemical characteristics in the sediments.