中文摘要：

为了解环境中Se的氧化还原行为和潜在的环境风险,本文采用氢化物发生器-原子荧光光谱法对元素Se与H2O2作用的机理进行了实验研究。结果显示,H2O2可将元素Se快速氧化,形成Se（4＋）和Se（6＋）的混合产物。反应分两步进行,首先是元素Se被氧化为Se（4＋）,而后是Se（4＋）转化为Se（6＋）。H2O2氧化元素Se的过程可用拟二级动力学方程描述,速率常数为0.0659m L·μg（-1）·h（-1）。推测H2O2分子在元素Se表层的吸附是H2O2氧化元素Se的控制步骤。

英文摘要：

For the purpose of understanding the redox behavior and potential environmental risks of Se,in this paper,hydride generator-atomic fluorescence spectrometry was used in studying the kinetic mechanism of elemental selenium oxidized to Se oxyanions by H2O2. The experimental results showed that elemental Se can be oxidized to the mixture of Se（ Ⅳ） and Se（ Ⅵ）.This reaction is carried out in two steps： The first is that elemental Se is oxidized to Se（ Ⅳ）,and Se（ Ⅳ） oxidized to Se（ Ⅵ） in the second step,which indicates that the oxidation of elemental Se by H2O2 can be described by the pseudo second-order rate law with rate constants of 0. 0659 m L·μg·h. According to experimental data,we suggested that chemical adsorption of H2O2 molecules onto the elemental Se surface is the rate-controlling step.