摘要： 采用沉淀法制备的MgO催化剂催化臭氧氧化水中氨氮，研究了pH、臭氧流量、催化剂投加量、时间和温度等因素对处理效果的影响。结果表明，500℃下煅烧得到的MgO的催化活性最高；在pH为9，MgO投加量为1 g/L，臭氧流量为12 mg/min，曝气时间为2 h，反应温度为60℃的条件下，当初始氨氮质量浓度为50 mg/L时，氨氮去除率可以达到96%，处理出水达到《地表水环境质量标准》（GB 3838—2002）的5类标准。叔丁醇抑制实验表明，MgO催化臭氧氧化氨氮的机理为MgO催化O₃分解产生·OH，从而使氨氮得到降解。动力学分析显示，该反应符合准一级动力学方程，相关系数为0.994 6。

关键词: 氨氮, MgO, 催化剂, 催化臭氧氧化

Abstract: MgO catalyst has been prepared by precipitation method for the catalytic ozonation of ammonia-nitrogen in water. The influences of factors,such as pH,ozone flow, dosage of catalyst,time,temperature,etc. on the treatment effect are investigated. The results show that the catalyzing activity of MgO obtained by calcination at 500℃ is the highest. Under the following conditions:the pH is 9,dosage of MgO 1 g/L,ozone flow 12 mg/min, aeration time 2 h,reaction temperature 60℃ and initial concentration of NH₄⁺-N 50 mg/L,the removing rate of ammonia-nitrogen is 96%. The treated effluent reaches the 5th kind of standard specified in Environmental Quality Standards for Surface Water (GB 3838-2002). Tert-butyl alcohol inhibition experiment indicates that the mechanism of MgO catalytic ozonation of ammonia- nitrogen in water is hydroxyl produced from the decomposition of MgO catalysis O₃,so as to degrade ammonia-nitrogen. Dynamics analysis show that the reaction complies with the pseudofirst- order kinetics equation, whose correlation coefficient is 0.994 6.

Key words: ammonia-nitrogen, MgO, catalyst, catalytic ozonation

中图分类号: 

• X703