【作者】 刘静；

【导师】 何士龙；

【作者基本信息】 中国矿业大学 ， 环境科学， 2021， 硕士

【摘要】 Fenton氧化技术由于处理效率高、运行费用低、操作管理简单等优点,广泛应用于难降解有机废水的处理中。但传统Fenton体系也存在适应的pH值范围在酸性、铁泥产生量较大等缺点。而利用固体催化剂代替Fenton试剂中的Fe²⁺来构建非均相类Fenton体系是解决上述问题的有效方法之一,研发高效的非均相类Fenton体系中的催化剂也就成了目前环境工程领域的热点之一。Fe₂（MoO₄）₃催化剂因其较强的固体酸性能常被用于类Fenton和光-Fenton反应中,但存在催化活性较低、催化剂投加量大等问题。鉴于此,本研究将Fe₂（MoO₄）₃催化剂作为非均相类Fenton反应催化剂,通过硫修饰以及掺杂Ce离子对该催化剂进行改性以提高其催化性能,并结合SEM、FT-IR、XRD等表征手段,探讨活性改善机制,为非均相类Fenton体系催化剂的选择与实践应用提供理论依据及数据支撑,主要研究结论如下:（1）通过共沉淀法在n（Fe）/n（Mo）=1:1.5、pH值为5、500℃焙烧2 h的条件下制备的Fe₂（MoO₄）₃催化剂,具有最佳催化性能。通过单因素实验以及响应曲面法得到在催化剂和H₂O₂投加量分别为0.414 g/L和33 mmol/L,pH值为7时邻苯二甲酸的去除率达到92.48%,TOC去除率为39.8%。自由基淬灭试验表明,反应的主要活性物种为Fe³⁺和MoO₄^2-协同催化产生的·OH。5次重复试验,邻苯二甲酸的去除率在80%以上,铁溶出量低于1mg/L,具有良好的稳定性和重复使用性能。（2）通过掺杂Ce催化剂进行改性,结果表明Ce掺杂量为15%的催化剂,在最佳反应条件下对邻苯二甲酸有95.94%的去除效果。掺杂15%Ce后的催化剂比表面积增大,催化剂特征吸收峰增强,具有良好的催化性能。5次重复试验后,催化剂对邻苯二甲酸的去除率仍然保持在85%以上,铁溶出量均低于0.63mg/L。（3）通过硫修饰改性得到的催化剂在最优条件下对邻苯二甲酸的去除率可以达到96.43%。XRD和FT-IR结果均表明,硫化后的催化剂存在酸中心,固体酸性能更强,对H₂O₂具有更强的作用,重复使用5次的催化剂对邻苯二酸去除率仍然在88%以上,且铁溶出量低于0.53 mg/L。硫修饰后得到的催化剂具有最高的催化性能、稳定性和重复使用性能。本文共有图39幅,表10个,参考文献82篇。更多还原

【Abstract】 Fenton technology has been extensively used in the treatment of refractory organic wastewater on account of its advantages of high treatment efficiency,low operation cost and convenient operation.However,the traditional Fenton system also has some disadvantages,such as the suitable pH range in acidity and large amount of iron sludge production.The use of solid catalyst instead of Fe²⁺in Fenton reagent to construct heterogeneous Fenton system is one of the effective methods to solve the above problems,research and development of efficient heterogeneous Fenton technology catalyst has been hot off the press in the field of environmental engineering.Fe₂（MoO₄）₃catalyst has often been used in Fenton-like and photo-Fenton reactions due to its strong solid acidity,but it has some problems such as low catalytic activity and large dosage of catalyst.In view of this,this study will Fe₂（MoO₄）₃catalyst as an all similar Fenton reaction catalyst,through the sulfur modified and doped Ce ions in the catalyst is modified to improve its catalytic properties,and combined with the characterization methods such as SEM,XRD,FT-IR,explore the activity to improve the mechanism,for not all similar Fenton system catalyst selection and practical application to provide theoretical basis and data support,the main research conclusions are as follows:（1）Under the conditions of n（Fe）/n（Mo）=1:1.5,pH value is 5,calcination time of2 h at 500℃,Fe₂（MoO₄）₃ catalyst prepared by co-precipitation method has the best catalytic performance.The single factor response surface methodology（RSM）showed that when the dosage of catalyst and H₂O₂ were 0.414 g/L and 33 mmol/L,respectively,and the pH value was 7,the removal rate of phthalic acid reached 92.48%,and the TOC removal rate was 39.8%.Free radical quenching experiments showed that the main active species in the reaction were·OH produced by the co-catalysis of Fe³⁺and MoO₄^2-.The removal rate of phthalic acid is more than 80%,the iron dissolution is less than1mg/L,and it has good stability and re-use performance.（2）The catalyst was modified by doping Ce catalyst.The results showed that the catalyst with 15%Ce doping amount could remove 95.94%of phthalic acid under the optimal reaction conditions.The catalyst doped with 15%Ce has higher specific surface area and higher characteristic absorption peak,which shows good catalytic performance.After five repeated tests,the removal rate of phthalic acid was still above85%,and the iron dissolution was lower than 0.63mg/L.（3）Under the optimal conditions,the removal rate of phthalic acid can reach96.43%.The results of XRD and FT-IR showed that the sulfurized catalyst had acid center,stronger solid acid energy,and stronger effect on H₂O₂.The removal rate of phthalic acid was still above 88%,and the iron dissolution amount was less than 0.53mg/L after the catalyst was reused for 5 times.The catalyst obtained by sulfur modification has the highest catalytic performance,stability and reusability.There are 39 figures,10 tables and 82 references in this paper.更多还原