大气水相H_2O_2-S(Ⅳ)反应动力学

THE KINETICS OF SULFUR (IV) -HYDROGEN PEROXIDE IN ATMOSPHERIC PRECIPITATION

对1988年6月至1989年10月在西南地区收集的59个雨水样品进行了H_2O_2氧化S(Ⅳ)的反应动力学研究,得出了其氧化速率.采用连续电流定量测量反应物浓度跟踪反应的程度.在影响H_2O_2-S(Ⅳ)反应的各种因素中,研究了甲醛对此反应的影响,进行了实验室动力学研究和计算比较,结果表明,甲醛不干扰大气水相中的H_2O_2-S(Ⅳ)反应.在pH为4.0的纯水反应媒介中(0—50℃),测定了H_2O_2-S(Ⅳ)反应的活化能,由此得到温度对此反应影响的阿伦尼乌斯公式.

The kinetics of the reaction of dissolved S(IV)with H2O2 was studied on 59 precipitation samples collected in Southwestern China,during the period of June 1988 to October 1989. The oxidation rates of the reaction were measured. The extent of the reaction was followed by continuous amperometric measurement of the concentrations of the reagents. The effect of formaldehyde on the reaction was also studied. It was indicated that formaldehyde with typical atmospheric concentration exerts no influence on the reaction of dissolved S(IV)with H2O2. In addition, the activation energy of the reaction was also measured in purified water as reaction medium for temperature range 0-50 ℃ at pH 4.0.