湖泊沉积物中镉的测定及环境意义研究

Research on determination of cadmium in the lake sediments and its environmental significance

建立了氢化物发生-原子荧光光谱法测定湖泊沉积物中镉的分析方法。优化了沉积物中镉的提取条件和测定条件,研究了Cu元素对测定镉的干扰及消除方法。以武汉市涨渡湖为例,通过对总镉和有效态镉的测定揭示了涨渡湖近百年来镉的各形态垂直分布特征。结果表明:自上世纪50年代以来,涨渡湖沉积物中的总镉由深层到表层呈上升趋势,有效态镉变化不大但其含量维持在较高水平。镉的潜在风险性较大。

A new method for the determination of cadmium in the sediments by hydride generation-atomic fluorescence spectrometry has been proposed. The optimum extraction processes, the experimental conditions by HG-AFS, interference of coexistent elements and elimination are investigated. This method is applied to the determination of cadmium in the sediments of Zhangdu lake in Wuhan city. The data of the total and available Cd contents have announced the ver- tical distribution features of Zhangdu lake in the 20th century. The experimental results indicate that the total Cd content keeps ascending trend from deep-bed to surface layer while the available cadmium is basically unchanged and remains on a relatively high level. Cadmium has not yet revealed the dangers but we should pay close attention to it.