Department of Environmental Resources Management, Chia-Nan University of Pharmacy and Science, Tainan 717, Taiwan.
National Center of Excellence for Environmental and Hazardous Waste Management, Department of Environmental Engineering, Faculty of Engineering, King Mongkut 's University of Technology, Thonburi, Bangkok 10140, Thailand.
Environ Technol. 2014 Jan-Feb;35(1-4):89-94. doi: 10.1080/09593330.2013.811543.
This study investigates the effects of the Fe2+ concentration and synthetic iron oxide catalysts on o-toluidine degradation using a fluidized-bed Fenton process. The mineralization ofo-toluidine in the synthetic catalyst system is also examined. The H3.5 and H7.3 Fe/SiO2 and A7.8 and A 12.5 Fe/SiO2 catalysts were successfully synthesized by adding H202 and injecting air process, respectively. The optimum initial ferrous ion concentration for degradation of 1 mM o-toluidine was 1 mM. Experimental results reveal that 1 mM o-toluidine can be 100% degraded at 60 and 120 min in the modified fluidized-bed Fenton process with A7.8 Fe/SiO2 and the conventional fluidized-bed Fenton process with SiO2 carrier, respectively, when the optimum conditions of 1mM Fe2+ and 17mM H202 at pH 3 were used. The A7.8 Fe/SiO2 catalyst had a stronger oxidation ability than the H3.5 Fe/SiO2, H7.3 Fe/SiO2 and A12.5 Fe/SiO2 catalysts, and was attributed to the high iron content on the surface of the SiO2 support. The Fenton and Fenton-like reactions occurred in the A7.8 Fe/SiO2 catalyst system. Degradation of o-toluidine in the Fenton-like process follows pseudo-first-order kinetics. The A7.8 Fe/SiO2 catalyst efficiently enhanced o-toluidine oxidation under the pH range of 2-4.
本研究采用流化床芬顿工艺考察了 Fe2+浓度和合成氧化铁催化剂对邻甲苯胺降解的影响，并考察了邻甲苯胺在合成催化剂体系中的矿化作用。通过添加 H2O2 和注入空气过程，成功合成了 H3.5 和 H7.3 Fe/SiO2 以及 A7.8 和 A12.5 Fe/SiO2 催化剂。降解 1mM 邻甲苯胺的最佳初始亚铁离子浓度为 1mM。实验结果表明，在优化条件下（pH 3 时分别为 1mM Fe2+和 17mM H2O2），在改性流化床芬顿工艺中使用 A7.8 Fe/SiO2 和传统流化床芬顿工艺中使用 SiO2 载体时，1mM o- 甲苯胺在 60 和 120 分钟内可完全降解。A7.8 Fe/SiO2 催化剂比 H3.5 Fe/SiO2、H7.3 Fe/SiO2 和 A12.5 Fe/SiO2 催化剂具有更强的氧化能力，这归因于 SiO2 载体表面的高铁含量。Fenton 和类 Fenton 反应发生在 A7.8 Fe/SiO2 催化剂体系中。类 Fenton 过程中邻甲苯胺的降解遵循准一级动力学。A7.8 Fe/SiO2 催化剂在 pH 值为 2-4 的范围内有效增强了邻甲苯胺的氧化。
