超声空化氧化过程中溴酸根的生成规律

Formation of bromate in aqueous solution in the presence of Br-under ultrasonic irradiation

研究了溴离子(Br^-)存在条件下,超声空化氧化过程中溴酸根(BrO_3^-)的生成机理及反应条件对其生成的影响。结果发现:超声过程中BrO_3^-的生成机理符合羟基自由基(·OH)氧化途径。BrO_3^-生成量随溴离子初始浓度的增加而增加,而溴离子转化率却随溴离子初始浓度的增加而减小。BrO_3^-的生成量随超声频率变化的大小关系为400>600>800>200kHz,存在最大的生成频率。超声声能密度从0.06 W/mL增大为0.19 W/mL时,溴酸根生成量先增大后减小。酸性条件下BrO_3^-的生成量较大,而碱性条件下BrO_3^-的生成量较小。

Formation of bromate（BrO3^-）in aqueous solution in the presence of Br^- under ultrasonic irradiation was investigated.The results show that BrO3^- formed by a series of reactions between hydroxyl free radical（·OH）generated by ultrasonic cavitation and Br^-.The total BrO3^- yield increases with the increase of the initial concentration of Br^-.While the yield ratio of BrO3^- to Br-decreases with the increased initial concentration of Br^-.The yield of BrO3^- at different frequencies follows the order 400〉600〉800〉200kHz.When the ultrasonic energy density increases from 0.06 W/Ml to 0.19 W/Ml,the formation rate of BrO3^- increases first and then decreases.BrO3^- formation rate decreases with the increase of Ph.