鄱阳湖及支流底泥中重金属形态研究

A Study on Heavy Metal Speciation in Sediment of Poyang Lake and Its Branches

采用五步连续萃提法区分了我国最大的淡水湖—鄱阳湖及支流底泥中的重金属(Cu、Co、Cd、Pb、N、iCr)的5种形态,结合原子吸收测定了各形态的含量。结果表明,Cu、Co、Cd、Pb、N i、Cr 6种元素的总量(mg/kg)分别为:26.79、16.11、1.52、36.16、23.38、35.35,其含量(mg/kg)最高的形态分别是:残渣态S5(11.70)、残渣态S5(8.70)、可交换态S1(0.44)、铁锰氧化物结合态S3(17.00)、残渣态S5(18.24)、残渣态S5(28.19)。除镉外,各元素生物可用性最高的可交换态含量普遍较低。同时对鄱阳湖及支流底泥中重金属进行了形态分析,确定了6种重金属在不同形态间的分配关系及地域分配关系,为鄱阳湖环境综合治理提供了参考数据。

In this study, an improved analytical method involving five - step sequential extraction was used to differentiate heavy metals （Cu, Co, Cd, Pb, Ni, Cr） in the sediment of Poyang Lake, the biggest fresh water lake in China, and its branches, in order to determine their environmental pollution level. The sediment samples were analyzed by using flame atomic absorption spectroscopy （FAAS）. The experimental resuits showed ： the average extracted contents of the six elements, according to the five - step analysis, were found to be （mg/kg） Cu： 26.79, Co： 16.11, Cd： 1.52, Pb： 36.16, Ni： 23.38, Cr： 35.35. The fractions containing most metals （mg/kg） for the above elements were S5 （ 11.70）, S5 （ 8.70）, S1 （0.44）, S3 （17.00）, S5 （18.24）, S5 （28.19）. Except for Cd, the content of the exchangeable species is generally lower. This is the first speciation analysis on the heavy metals in the sediment of Poyang Lake and its branches. Acccording to the results, the distribution relationships of the six metals are determined. The data can be used for the control of the environment of Poyang Lake.