Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan, 030051, Shanxi, China.
Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
Environ Sci Pollut Res Int. 2018 Sep;25(25):25060-25070. doi: 10.1007/s11356-018-2551-8. Epub 2018 Jun 23.
The rotating packed bed (RPB) as a continuous flow reactor performs very well in degradation of nitrobenzene wastewater. In this study, acidic nitrobenzene wastewater was degraded using ozone (O) combined with hydrogen peroxide and titanium ions (Ti(IV)/HO/O) or using only HO/O in a RPB. The degradation efficiency of nitrobenzene by Ti(IV)/HO/O is roughly 16.84% higher than that by HO/O, and it reaches as high as 94.64% in 30 min at a HO/O molar ratio of 0.48. It is also found that the degradation efficiency of nitrobenzene is significantly affected by the high gravity factor, HO/O molar ratio, and Ti(IV) concentration, and it reaches a maximum at a high gravity factor of 40, a Ti(IV) concentration of 0.50 mmol/L, a pH of 4.0, a HO/O molar ratio of 0.48, a liquid flow rate of 120 L/h, and an initial nitrobenzene concentration of 1.22 mmol/L. Both direct ozonation and indirect ozonation are involved in the reaction of O with organic pollutants. The indirect ozonation due to the addition of different amounts of tert-butanol (·OH scavenger) in the system accounts for 84.31% of the degradation efficiency of nitrobenzene, indicating that the nitrobenzene is dominantly oxidized by ·OH generated in the RPB-Ti(IV)/HO/O process. Furthermore, the possible oxidative degradation mechanisms are also proposed to better understand the role of RPB in the removal of pollutants. Graphical abstract ᅟ.
旋转填充床（RPB）作为连续流反应器在降解硝基苯废水方面表现非常出色。在这项研究中，使用臭氧（O）与过氧化氢和钛离子（Ti(IV)/HO/O）结合或仅在 RPB 中使用 HO/O 来降解酸性硝基苯废水。Ti(IV)/HO/O 对硝基苯的降解效率比 HO/O 高约 16.84%，在 HO/O 摩尔比为 0.48 时，30 分钟内可达到 94.64%。还发现，硝基苯的降解效率受到高重力因子、HO/O 摩尔比和 Ti(IV)浓度的显著影响，在高重力因子为 40、Ti(IV)浓度为 0.50mmol/L、pH 值为 4.0、HO/O 摩尔比为 0.48、液体流速为 120L/h 和初始硝基苯浓度为 1.22mmol/L 时达到最大值。O 与有机污染物的反应涉及直接臭氧化和间接臭氧化。由于在系统中添加了不同量的叔丁醇（·OH 清除剂），间接臭氧化占硝基苯降解效率的 84.31%，表明硝基苯主要被 RPB-Ti(IV)/HO/O 过程中生成的·OH 氧化。此外，还提出了可能的氧化降解机制，以更好地理解 RPB 在去除污染物中的作用。
