[目的]揭示珠江上游多介质典型重金属Pb、Zn的含量与分布特征,存在形态与环境风险之间的关系以及迁移规律.[方法]测定了珠江上游南盘江流域农田、非农田土壤及沉积物中Pb、Zn的含量,并采用BCR连续提取法分析了Pb、Zn的存在形态.[结果]研究区农田土壤部分样点存在Pb、Zn不同程度富集,但多数农田土壤Pb、Zn含量未超过中国土壤质量标准(GB15618-1995)的限值,沉积物中Pb、Zn含量也未超过欧盟淡水沉积物Pb、Zn标准(EC standard)限值.位于工业区(A8样点)农田和非农田土壤Pb、Zn含量显著高于其它样点.[结论]3种介质中的Pb、Zn形态分布模式是相似的,Zn的迁移性高于Pb,沉积物Pb、Zn 的迁移性高于土壤.%[Objective] The objective of this study is to reveal concentration and distribution of typical heavy metals (Pb and Zn),and to understand the relationship between its speciation and environmental risks as well as its transfer rules.[Method] The concentration of Pb and Zn in agricultural,non-agricultural soils and sediment were investigated in upstream of the Pearl River,China.The sequential extraction procedure recommended by BCR method was applied to study the speciation of Pb and Zn.[Result]The results suggested that,Pb and Zn were accumulated somehow in several of the samples in agricultural soil,and their concentrations in all the sampling sites did not exceeded the maximum allowable concentrations of China agricultural soil standard (GB15618-1995).Total concentrations of Pb and Zn in all the sampling site for sediment also did not exceeded standard values of European commission for freshwater sediments (EC standard).Total Pb and Zn concentrations of site A8 in agricultural and non-agricultural soils were significantly higher than those of other sites.Agricultural,non-agricultural soils and sediment were similar in their Pb and Zn speciation distribution.[Conclusion] The mobility of Zn were higher than Pb in three media,and the mobility of Pb and Zn in sediment were higher than in both agricultural and non-agricultural soils.
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