Al2O3负载ZnO催化臭氧氧化处理造纸废水的研究

Catalytic Ozonation Treatment of Papermaking Wastewater by Al2O3 Loaded with ZnO

中文关键词:  催化臭氧  造纸废水  Al₂O₃@ZnO催化剂

Key Words:catalytic ozonation  papermaking wastewater  Al₂O₃@ZnO catalyst

中文摘要:

      将ZnO负载在Al₂O₃上，制备用于催化臭氧降解造纸废水中有机物的催化剂（Al₂O₃@ZnO）；采用场发射扫描电子显微镜（SEM）和X射线衍射仪（XRD）对Al₂O₃@ZnO催化剂进行物相分析；研究了造纸废水的初始pH值、反应时间和催化剂用量对Al₂O₃@ZnO催化臭氧氧化处理造纸废水效果的影响；并进行了自由基捕集剂叔丁醇实验，以探讨降解造纸废水中有机物的主要因素。结果表明，本研究成功制备了具有良好催化性能的Al₂O₃@ZnO催化剂；在造纸废水初始pH值为11、催化剂用量为2.0 g/L、反应时间为60 min的条件下，Al₂O₃@ZnO催化剂对造纸废水中COD_Cr的去除率可达到84.6％，与单独使用臭氧氧化方法相比，COD_Cr去除率明显提高，且COD_Cr的动力学降解反应遵循准一级动力学方程；叔丁醇的实验结果表明，在Al₂O₃@ZnO催化臭氧氧化处理造纸废水有机物的过程中，羟基自由基是降解废水有机物的主要因素。

Abstract:

      A catalyst loading ZnO on Al₂O₃ for oxidative degradation of papermaking wastewater was prepared. The properties of the catalyst was characterized by XRD and SEM. The effects of initial pH value of papermaking wastewater， reaction time， and catalyst dosage on the treatment of papermaking wastewater were studied. In addition， the effect of the free radical trapping agent tert-butanol on the catalytic ozone treatment of wastewater was also characterized. The characterization results showed that the Al₂O₃@ZnO catalyst with good catalytic performance was successfully prepared. Under the conditions of pH value=11， catalyst dosage of 2.0 g/L， and reaction time of 60 min， the removal rate of chemical oxygen demand （COD） reached 84.6%. Furthermore， the removal rate of the catalytic ozonation method was significantly higher than that of the ozonation method alone. The kinetic degradation reaction of COD_Cr followed a quasi-first-order equation. The experimental results of tert-butanol showed that in the process of Al₂O₃@ZnO catalyst treating organic matter in papermaking wastewater， hydroxyl radical was the main factor in the degradation of organic matter in wastewater.