中文摘要：

为了探索Fe^3＋催化氧化S（Ⅳ）的反应动力学规律,实验考察了pH、Fe^3＋浓度、S（Ⅳ）浓度、温度对反应动力学的影响.结果表明,Fe^3＋催化氧化S（Ⅳ）过程中动力学控制步骤为Fe^2＋的氧化,且pH在0～3范围内,氧化速率随着H＋浓度的升高而降低;Fe^3＋浓度为0～0.01 mol·L^-1时,氧化速率随Fe^3＋浓度的增加而加快,继续增加Fe^3＋浓度,氧化速率没有明显变化;S（Ⅳ）浓度为0～0.1 mol·L^-1时,氧化速率随S（Ⅳ）浓度的增加而加快.由实验数据得到了氧化速率公式.反应速率在20～40 ℃范围内随温度升高而加快,反应活化能约为13kJ·mol^-1.在实验基础上推测反应为自由基链反应机理.

英文摘要：

The effect of pH, concentration of Fe^3 ＋ and S（Ⅳ） and temperature on the kinetics of Fe （ Ⅲ ） catalyzed oxidation of S（Ⅳ） is presented in the present work. The oxidation of Fe^2 ＋ was the rate-determining step in the Fe^3 ＋ catalyzed oxidation of S（Ⅳ）. The rate of Fe^2 ＋ oxidation decreased with increasing concentration of H ^＋ when the pH of the solution was within the range of 0 - 3, while the rate of Fe^2 ＋ oxidation increased with increasing concentration of Fe^3 ＋ within the range of 0 - 0.01 mol· L^ -1. The oxidation rate did not change significantly at higher concentrations of Fe^3 ＋ . The rate of Fe^2 ＋ oxidation increased with the increasing concentration of S（Ⅳ） within the range 0 -0. 1 mol· L ^-1. The rate of Fe^2 ＋ oxidation was first order with respect to Fe^3 ＋ concentration and S（Ⅳ） concentration according to the experimental data. The oxidation rate increased with temperature from 20 to 40℃, and had an activation energy of 13 kJ·mol^ -1. The mechanism of Fe （ Ⅲ ） catalyzed oxidation of S（Ⅳ） , a radical chain reaction, is described.