基于市政污泥的高效非均相Fenton催化材料的制备及其性能研究

Preparation of Heterogeneous Fenton Catalyst Derived from Dewatered Sludge and Catalytic Performance

以市政脱水污泥和(NH_4)_2Fe(SO_4)2·6H_2O试剂为原料,通过超声-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,探讨了泥铁质量比、焙烧温度和时间等因素对催化剂性能的影响,确定了最佳的制备条件,并运用SEM、FT-IR和XRD等方法对合成样品进行表征,探究了所制备催化剂降解亚甲基蓝(MB)模拟废水的性能。试验结果表明,最佳的制备条件为泥铁质量比1∶0.8,焙烧温度为500℃,焙烧时间为120 min。污泥基非均相Fenton催化剂中的铁元素主要以Fe_2O_3的形式存在,并能均匀、分散地负载于污泥载体上,负载铁元素与污泥载体之间形成了Si-O-Fe和Fe-O键,具有较好的稳定性。在考察不同体系下MB降解试验发现,制备时引入超声作用可有效提高催化剂性能,反应80 min后对MB的脱色率可达99%,是污泥载体和铁氧化物为表面活性点位协同作用的结果。本研究提出了便捷的、环境友好的污泥回用方法,可有效降解染料废水,达到以废治废。

Heterogeneous Fenton catalyst with high stability and catalytic ability was synthesized using dewatered sludge and(NH4)2 Fe(S04)2.6H2O solution as raw materia,which was prepared by ultrasound assisted impregnation method and fully characterized by means of SEM、XRD、FT-IR.In addition,its performance in catalytic degradation of Methylene Blue(MB)was studied.The results indicated that the optimum parameters(dewatered sludge/(NH4)2Fe(S04)2.6H2O mass ratio 1~0.8,calcination temperature 500℃,calcination time 120 min)for preparation of the catalyst were obtained by single factor experiments.While iron element was present in the catalyst in the form of Fe20 3,and new chemical bonds Si-O-Fe and Fe-0 were formed between iron element and silicon dioxide.The catalytic activity was evaluated by degradation of MB under heterogeneous Fenton system,which manifested that the ultrasound assisted impregnation method could be effective approach for improving catalyst performance,and 99%discoloration were achieved within 80 min under optimum conditions.The synergistic effect between the sludge as carrier and Fe20 3was proved to exist,which could promote the degradation of MB.This protocol provides an alternative environmentally friendly sludge reuse method and dewatered sludge,which was difficult to handle,can be used for the preparation of heterogeneous Fenton catalyst.