超声-浸渍法制备污泥负载型高效非均相Fenton催化剂及其催化性能

基于简易的超声-浸渍法将铁元素成功掺杂于污泥载体上,得到了一种高效稳定的非均相Fenton催化剂,并运用X射线衍射(XRD)、扫描电子显微镜(SEM)、电感耦合等离子体发射光谱(ICP)和傅立叶变化红外光谱(FT-IR)等对合成催化剂的结构和性能等进行表征,探究了所制备催化剂对亚甲基蓝(MB)模拟废水的降解行为。结果表明,以脱水污泥为载体,可快速有效将铁元素掺杂于污泥中,并主要以Fe2O3的形式存在,且负载铁元素和载体形成了Fe-O、Fe-O-H和Si-O-Fe等化学键,保证催化剂的稳定性。对50mg/L MB的降解实验表明,在初始pH为4、催化剂用量为0.6g/L、H2O2投加量为5mL/L的最优实验条件下,反应120min后对MB的降解率可达99.8%,并且循环实验5次仍能保持较好的催化性能。同时阐明了非均相Fenton催化体系对MB可能的降解机理。

Preparation of heterogeneous Fenton catalyst derived from dewatered sludge using ultrasound-enhanced impregnation method and its catalytic performance

Heterogeneous Fenton catalyst with high stability and catalytic ability was prepared by ultrasound-enhanced impregnation method and fully characterized by means of X-ray diffraction(XRD),scanning electron microscope(SEM),inductively coupled plasma(ICP)and Fourier transform infrared spectrometer(FT-IR).The catalytic performance of the catalyst was analyzed by degradation of methylene blue.The results indicated that iron element was present in the catalyst in the form of Fe2O3,and new chemical bonds Fe-O,Fe-O-H and Si-O-Fe were formed between iron element and dewatered sludge.In the degradation experiment of 50 mg/L simulated methylene blue wastewater(MB),under the optimal experimental conditions of initial pH=4,amount of the catalyst of 0.6 g/L and the H2O2 concentration of 5 mL/L,the degradation rate of the catalyst for MB was found to be 99.8%after reaction of 120 min.Moreover,there were no distinct changes in the degradation capacity during the 5 cycles under the optimum conditions,which suggested that the catalytic material had excellent stability of catalytic activity.Meanwhile,the possible degradation mechanism was analyzed for the heterogeneous Fenton system in the degradation of MB.