铬污染归宿的同位素原位监测法

MONITORING THE FATE OF CHROMIUM CONTAMINATION USING ISOTOPE ANALYSIS

铬(Cr)污染的迁移和环境毒性主要取决于其化学形态。在环境中,如果移动性及毒性较大的Cr(Ⅵ)能被还原为移动性及毒性较小的Cr(Ⅲ),并且还原速率大于污染速率,那么对铬污染的自然生态修复治理是可行的。铬在氧化还原过程中,存在着同位素动力学分馏效应,致使同位素比率发生移动,移动的大小和反应进程有关,服从Reyleigh关系方程。因此,利用同位素测定可以确定Cr(Ⅵ)的归宿,用于铬(Cr)污染自然修复的监测。本文就环境铬污染自然生态修复中,应用同位素原位分析法进行监测的基本原理、分析过程及应用的可行性进行了阐述。

The movement and environmental toxicity of Chromium contamination would be extensively determined by its chemical form and Cr（ Ⅵ ）, which is mobile and suspected carcinogen and may convert to Cr（ Ⅲ）, which is less mobile and less toxic, when there is sufficient rates of natural reduction, the ＂monitored natural attenuation＂ approach would be expected. Ellis et al associated chromium now reported that the ^53 Cr/^52 Cr ratio changes during reduction of Cr （Ⅵ ） to Cr （ Ⅲ ）, shift of isotope ratio extent of reducing process whit Reyleigh formula, therefore tracking 53 Cr in Cr （Ⅵ） may monitor the fate contamination. In the paper, the background of theory, sampling and test examples on the topic are clarified.