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基于2012年夏季对南黄海南部海域的调查资料,分析了表层沉积物中7种重金属元素的含量分布特征;采用多元统计分析,揭示了研究区表层沉积物重金属污染的主要来源及各元素之间的相关性;应用地质累积指数法和Hakanson潜在生态风险指数法对重金属元素进行了污染及风险分析.结果表明:Cd、Pb的含量均符合国标规定的一类沉积物标准,Zn、Cu、Cr在绝大部分站位也都低于国标规定的一类沉积物的最高标准,仅在个别站位处达到二类或三类沉积物标准;除Cr、Cd、Mn外,其余各重金属与Al2O3、平均粒径之间有显著的相关性,表明它们均以自然来源为主,并受到沉积物粒度的控制,遵循“元素的粒度控制律”;Cr、Cd、Mn与Al2O3的相关系数较小,表明其可能受到人为污染源的影响.通过主成分分析和聚类分析可将7种重金属元素辨识为2个主成分,PC1(Zn、Cu、Pb、Fe、Mn)为自然源因子,PC2(Cr、Cd)为工农业源因子;其中,Cr、Cd在PC1和PC2上均具有一定的正载荷,受自然地质背景和人类活动的共同控制.地质累积指数法评价结果表明,Zn、Cu、Cd、Pb整体均处于清洁级别,而Cr则处于轻微污染水平,污染程度排序依次为Cr>Pb>Cd>Zn>Cu;潜在生态风险评价结果表明,各元素潜在生态危害等级排序依次为Cd>Pb>Cu>Cr>Zn,Cr、Zn、Cu和Pb均为低生态危害等级,Cd以低中等生态危害等级为主,局部出现较重生态危害等级,综合潜在生态风险评价为低度.
Based on the survey data of the southern South Yellow Sea in summer of 2012, the distribution characteristics of seven heavy metal elements in surface sediments were analyzed. By using multivariate statistical analysis, the main sources of heavy metal pollution in surface sediments and the relationships among the elements The results showed that the contents of Cd and Pb all met the criteria of a kind of sediment regulated by national standard, and the contents of Zn, Cu, Cr In most of the stations are also lower than the national standard of a class of sediments, the highest standards, only at individual stations to achieve two or three types of sediment standards; except Cr, Cd, Mn, the rest of the heavy metals and Al2O3 , And the average particle size, indicating that they are mainly from natural sources and are controlled by the grain size of the sediment and follow the “grain size control law” of elements. The correlation coefficients of Cr, Cd, Mn and Al2O3 Which indicates that it may be affected by anthropogenic pollution sources.The seven heavy metal elements can be identified as two principal components by principal component analysis and cluster analysis.The PC1 (Zn, Cu, Pb, Fe, Mn) PC2 ( Cr, Cd) were the source of agriculture and industry. Among them, Cr and Cd had certain positive loads on both PC1 and PC2, and were controlled by the natural geological background and human activities. The evaluation results of Geological Cumulative Index showed that Zn, Cu, Cd and Pb are all in the cleanliness level while Cr is slightly polluted. The order of pollution degree is Cr> Pb> Cd> Zn> Cu. The potential ecological risk assessment results show that the order of potential ecological risk of each element is Cd> Pb> Cu> Cr> Zn, Cr, Zn, Cu and Pb, respectively. All of them were low and medium ecological hazard level, while heavy local ecological hazard level and integrated potential ecological risk were low.