臭氧在水中溶解度及氧化除锰的动力学研究

Study on the Solubility of Ozone and the Kinetics of Manganese Removal by Oxidation

采用碘量法研究了不同进口空气流量、pH值、温度等条件对臭氧溶解特性的影响。结果表明,在进口空气流量100 L/h、常温20℃、pH1.5左右时,臭氧在水中的溶解度最高达62.22 mg/L。在此基础上进行了不同空气进口流量下锰脱除的试验和动力学研究。结果表明,随着空气流量的增加,Mn的脱除率呈现出先增加后减小的趋势,当空气流量为100 L/h时,Mn的脱除率最高达99.99%。动力学研究结果表明,臭氧氧化去除水中的锰离子符合拟一级动力学特征,即扩散是其限制性环节,溶液中Mn^(2+)被臭氧氧化后水解形成α-MnO_(2)沉淀形式从溶液中被去除。

The effect of inlet air flow rate,pH and temperature on the solubility of ozone were investigated by iodometric method.The results showed that the solubility of ozone was up to 62.22 mg/L at the optimized parameters,such as air flow rate of 100 L/h,temperature of 20℃and pH of about 1.5.Based on the ozone solubility,the experiment and kinetic study of manganese removal using ozone under different air flow rates was carried out.The results showed that the removal rate of Mn increased and then decreased with the increase of air flow rate.At 100 L/h air flow rate,the removal rate of Mn was reached up to 99.99%.The kinetics results indicated that the Mn removal by ozone followed the pseudo-first-order kinetics,and was controlled by diffusion.Mn^(2+)was oxidized by ozone and then hydrolyzed to formα-MnO_(2) precipitate to be removed from the aqueous solution.