二氧化氯对过量硫代硫酸钠氧化的动力学  

Kinetics of excess thiosulfate oxidation with chlorine dioxide

作　　者：曹向禹[1,2] 崔崇威[1] 黄君礼[1] 李绍峰[3] 

机构地区：[1]哈尔滨工业大学市政环境工程学院,哈尔滨150090 [2]齐齐哈尔大学轻纺学院,黑龙江齐齐哈尔161006 [3]深圳职业技术学院建筑工程系,广东深圳518055

出　　处：《哈尔滨工业大学学报》2008年第12期1923-1926,1936,共5页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金资助项目(50178022);国家高技术研究发展计划项目(863-2006AA06Z309)

摘　　要：为研究过量硫代硫酸钠与ClO2的反应动力学及其机理,采用停流技术测定该反应过程中各物质的浓度变化.结果表明,该化学反应方程式为:3S2O32-+2ClO2+H2O→S4O62-+2SO42-+2Cl-+2H+,建立相应的反应动力学方程,该反应对于ClO2和硫代硫酸钠均为一级,对S4O62-为0.5级,获取pH=9.27、T=298K和[S2O32-]0/[ClO2]0浓度范围为1.2～3.7情况下该反应的速率常数k值为2.8251×105L1.5/(mol1.5.s),反应活化能Ea为20.5kJ/mol,表明在一般的水处理研究中,硫代硫酸钠作为ClO2的猝灭剂是合理的,提出过量硫代硫酸钠与ClO2的4步反应机理,指出S2O3ClO22-是反应中重要的中间体,说明该反应遵循单电子转移机理.Kinetics and mechanism of the reaction between excess thiosulfate and ClO2were studied by following the concentration change of reactive substances with the stopped-flow technique. Results showed that the stoichemistry was found to be 3S2O3^2- ＋2ClO2 ＋ H20→S4O6^2- ＋2SO4^2- ＋2Cl^- ＋2H^＋. The equation of reaction kinetics was established. The reaction was first-order with respect to both ClO2 and thiosulfate, and half-order to tetrathionate. When pH was 9. 27, water temperature was 298 K and ratio of [ S2O3^2- ]0/[ ClO2]0 ranged from 1.2 to 3. 7, the order reaction rate constant k was 2. 8251 × 10^5 L^1.5/（mol^1.5 · s）, and the reaction activation energy was 20. 5 kJ/mol, which reveals that taking thiosulfate as the fast terminating reagent of ClO2 is reasonable under usual water treatment conditions. A 4-step mechanism based on the theory of single electron transfer（SET） between excess thiosulfate and ClO2 is proposed, in which S2O3ClO2^2- plays a significant role.

关 键 词：二氧化氯 硫代硫酸钠 动力学 反应机理 

分 类 号：TU991.2[建筑科学—市政工程]