【摘要】 基于2008年1月对东洞庭湖6个具代表性监测断面的采样分析,通过地累积指数模型、多变量分析理论和主成分分析法,研究了东洞庭湖沉积物中重金属的污染富集分布特征及其主要来源.结果表明,沉积物中重金属元素Cd和Hg在各采样断面的污染富集程度均较高,尤其是在樟树港、洞庭湖出口2个采样断面的污染富集程度达到重度污染水平.相关分析表明,w(Pb),w(Hg),w(Cd)和w(Zn)之间呈显著正相关,w(Cr)与w(As)之间也呈显著正相关,其他重金属之间无显著的相关性.通过主成分分析研究了重金属的来源,发现2个主成分的贡献率分别为52.267%和33.380%.结合洞庭湖水系自身特点及周边点源、非点源污染情况,将东洞庭湖沉积物中的重金属划分为2类:Pb,Hg,Cd和Zn作为第一主成分,主要受人类活动中的工矿业采冶支配;第二主成分为Cr与As,与人类活动中的生活污水排放和农业生产有密切关系.更多还原

【Abstract】 The distribution characteristics of pollution accumulation and main sources of heavy metals in sediment from East Dongting Lake were investigated based on analysis of samples from six representative monitoring sections in January 2008 by the geo-accumulation index model,multivariable analysis theory and principal component analysis method.The results showed that the enrichment degree of Cd and Hg became higher at each station,especially in the Zhangshugang Station and the exit of the Dongting Lake Station,reaching a severe pollution level.Correlation analysis indicated that significant positive correlations existed among w(Pb),w(Hg),w(Cd) and w(Zn) and as well as w(Cr) and w(As),but there was no significant correlation between other heavy metals.Principal component analysis was applied to estimate the sources of heavy metals in the sediment.It was found that the first two components accounted for 52.267% and 33.380% of the total variance.On the basis of previous research and information on the Dongting hydrographic net,the first principal components included Pb,Hg,Cd and Zn,which were considered to come from mining and heavy industry.The second principal components included Cr and As,which were probably from agricultural contamination and sewage.更多还原