ABSTRACT

Nanoscale composite metal oxide of Ag-La-Co was prepared by co-precipitation method for the treatment of Reactive Black 5 using catalytic ozonation process. Further, the catalyst was characterized by transmission electron microscope, X-ray powder diffraction (XRD), scanning electron microscope - energy dispersive X-ray (SEM-EDX) and Brunauer–Emmett–Teller (BET) surface area analyzer for clarity of the phenomenon. The factors such as amount of catalyst (0.2–1.2 g/L), solution pH (2, 7, and 12), initial dye concentration (100–1,000 mg/L), and ozone flow rate (30–60 LPH) were found to influence the process. The characterization results confirm the formation of the composite metal oxide of Ag-La-Co. The degradation efficiency of catalytic ozonation was 63% compared to 32% and 4% in ozonation without catalyst and adsorption on the catalyst, respectively. Furthermore, it was observed that a pseudo-first-order kinetics model fits well with the experimental data. In addition, the effect of tert-butyl alcohol, a hydroxyl radical scavenger, has been studied. Lastly, the repetitive use of the synthesized catalyst showed that even after three consecutive runs, the catalytic activity is not much degraded, and therefore, the degradation efficiency of the synthesized catalyst was comparatively high; about 95% of Total Organic Carbon (TOC) removal was achieved at solution pH 7, amount of catalyst 1 g/L, reaction time 80 min, and ozone flow rate 30 LPH, indicating an economically viable option for industrial wastewater treatment.

摘要

采用共沉淀法制备Ag-La-Co纳米复合金属氧化物，用于催化臭氧化处理活性黑5。此外，通过透射电子显微镜、X 射线粉末衍射 (XRD)、扫描电子显微镜-能量色散 X 射线 (SEM-EDX) 和 Brunauer-Emmett-Teller (BET) 表面积分析仪对催化剂进行了表征，以确保催化剂的清晰度现象。催化剂用量（0.2-1.2 g/L）、溶液 pH 值（2、7 和 12）、初始染料浓度（100-1,000 mg/L）和臭氧流速（30-60 LPH）等因素为发现影响进程。表征结果证实了Ag-La-Co复合金属氧化物的形成。催化臭氧化的降解效率为 63%，而无催化剂和吸附在催化剂上的臭氧化为 32% 和 4%，分别。此外，观察到伪一级动力学模型与实验数据非常吻合。此外，还研究了羟基自由基清除剂叔丁醇的作用。最后，合成催化剂的重复使用表明，即使连续运行3次，催化活性也没有明显下降，因此合成催化剂的降解效率较高；在溶液 pH 值为 7、催化剂用量为 1 g/L、反应时间为 80 分钟、臭氧流速为 30 LPH 时，可实现约 95% 的总有机碳 (TOC) 去除，表明工业废水处理的经济可行选择。羟基自由基清除剂，已被研究。最后，合成催化剂的重复使用表明，即使连续运行3次，催化活性也没有明显下降，因此合成催化剂的降解效率较高；在溶液 pH 值为 7、催化剂用量为 1 g/L、反应时间为 80 分钟、臭氧流速为 30 LPH 时，可实现约 95% 的总有机碳 (TOC) 去除，表明工业废水处理的经济可行选择。羟基自由基清除剂，已被研究。最后，合成催化剂的重复使用表明，即使连续运行3次，催化活性也没有明显下降，因此合成催化剂的降解效率较高；在溶液 pH 值为 7、催化剂用量为 1 g/L、反应时间为 80 分钟、臭氧流速为 30 LPH 时，可实现约 95% 的总有机碳 (TOC) 去除，表明工业废水处理的经济可行选择。