太湖沉积物中重金属的地球化学形态及特征分析  

Chemical partitioning of heavy meta ls and their characteristics for sediments from Lake Taihu

作　　者：袁旭音[1] 王爱华[2] 许乃政[2] 

机构地区：[1]河海大学环境科学与工程学院,江苏南京210098 [2]中国地质调查局南京地质矿产研究所,江苏南京210016

出　　处：《地球化学》2004年第6期611-618,共8页Geochimica

基　　金：江苏省自然科学重点基金(BK99204)

摘　　要：用连续提取法分析了太湖沉积物5种重金属的地球化学形态,对地球化学形态的组成和地理特征进行了分析研究。重金属地球化学形态配分的共同特点是可交换态最低,残渣态最高。两种形态中Cd的可交换态最高,Cr的残渣态最高,可交换态最低。Cd的碳酸盐态较高,Cr的最低;Pb、Cd的Fe-Mn氧化态较高,Cu的偏低;Cu的有机态最高,Cd的最低;Zn的地球化学形态比例大都处于中间。地域上变化较大的元素是Cd和Cu,变化不明显的元素有Pb和Zn。化学成分中Fe2O3、MnO与重金属地球化学形态的相关性最好,TOC与Cu的形态相关系数最高。综合对比分析表明,太湖沉积物重金属的生物有效性以Cd为最高,其次为Pb。The speciations of heavy metals(Cu,Pb,Zn,Cd and Cr )in sediments from Lake Taihu are analyzed using a sequential extraction proce dure.Variations of chemical fractions for elements and geographic situ ations are studied.It is found that the residual fraction is the highest and the exch angeable fraction is the lowest for t he five metals in these sediments.Among the five metals,exchangeable Cd has the highest percentage of chemical fraction.Cr is mainly associated wi th the residual.The Cu bound to organ ic fraction and Pb bound to Fe-Mn fraction are the important phases.W hereas the Cd bound to the organic fra ction,Cu bound to the Fe-Mn oxides an d Pb bound to the carbonate fraction sh ow the lowest percentages in sedimen ts.The Cd bound to the non-residual fractions decreases from the bay to t he center of the lake.The Cu associated to organic matter and Cr associate d to residual increases from the coast to the center of the lake.The speciatio ns of Pb and Zn do not show significant variations in the special distribut ion.Fe 2 O 3 ,MnO show the higher correlation wit h speciation of heavy metals.The highest correlation coefficients a re present between total organic carbon and Cu speciation.Comparison of results may reflect that Cd has the strongest bioavailability and Pb does the next one for the five metals.

关 键 词：沉积物 重金属 连续提取法 元素地球化学形态 太湖 

分 类 号：P595[天文地球—地球化学]