Wang Xi, Zhu Kai, Ma Xiaoyue, Sun Zhirong, Hu Xiang
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, College of Environmental and Energy Engineering, Beijing University of Technology Beijing 100124 China
College of Chemical Engineering, Beijing University of Chemical Technology Beijing 100029 China
RSC Adv. 2018 May 30;8(36):19971-19978. doi: 10.1039/c8ra02776e.
In this work, polytetrafluoroethylene coating was firstly conducted to make stable and effective magnetic-activated carbon as a heterogeneous electro-Fenton catalyst for diuron oxidation. The catalysts were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). In addition, the effects of operating parameters such as catalyst dosage, current intensity, substrate concentration and pH on the degradation of diuron were investigated. The removal efficiency of diuron was more than 95% within 120 min oxidation under the conditions of = 100 mA, pH = 6.7 ± 0.2, catalyst loading 3 g L and diuron concentration 10 mg L. Moreover, the catalyst durability test demonstrated that the modification of 5% PTFE on the catalyst indeed has a significant beneficial effect on the useful life of the catalyst. We compared the performance of catalysts with or without PTFE modification in consecutive experiments; the modified catalysts exhibited remarkable advantages in that the diuron removal efficiency was stable with relatively low iron leaching (<0.1 mg L) during ten consecutive degradation experiments, which proved the durability and reusability of the modified catalyst. This work demonstrates that such a heterogeneous EF using stable magnetic activated carbon catalyst with PTFE modification is promising for organic wastewater treatment in initial neutral pH conditions; at the same time, these good properties of the modified catalyst increase the possibility of practical application.
在本工作中，首先对聚四氟乙烯进行涂层处理，以制备稳定且有效的磁性活性炭，作为用于敌草隆氧化的非均相电芬顿催化剂。通过扫描电子显微镜（SEM）、X射线光电子能谱（XPS）和X射线衍射（XRD）对催化剂进行了表征。此外，研究了催化剂用量、电流强度、底物浓度和pH等操作参数对敌草隆降解的影响。在电流强度为100 mA、pH = 6.7±0.2、催化剂负载量为3 g/L和敌草隆浓度为10 mg/L的条件下，氧化120分钟内敌草隆的去除效率超过95%。此外，催化剂耐久性测试表明，催化剂上5%聚四氟乙烯的改性确实对催化剂的使用寿命有显著的有益影响。我们在连续实验中比较了有无聚四氟乙烯改性的催化剂的性能；改性催化剂表现出显著优势，即在连续十次降解实验中，敌草隆去除效率稳定，铁浸出量相对较低（<0.1 mg/L），这证明了改性催化剂的耐久性和可重复使用性。这项工作表明，这种使用经聚四氟乙烯改性的稳定磁性活性炭催化剂的非均相电芬顿法在初始中性pH条件下处理有机废水具有前景；同时，改性催化剂的这些良好性能增加了实际应用的可能性。
