【作者】 李慧；

【导师】 陈桂秋； 曾光明； 孙赛武；

【作者基本信息】 湖南大学 ， 环境工程（专业学位）， 2019， 硕士

【摘要】 随着工业的快速发展,产生的诸多有机污染物被无意识地释放,然后进入水体,尤其是排放的染料废水对水环境和生态环境造成了严重的危害。为了使受污染的水体得到治理,许多方法被研究开发,其中利用催化剂催化还原有机染料被大力推崇。为了探究高效、节约和环保的催化剂,本研究通过原位还原法制备了Ag纳米颗粒负载聚多巴胺涂层包覆磁性生物炭的催化材料（MC-PDA-Ag）。MC-PDA-Ag复合催化材料的表面形态、元素组成和化学结构通过透射电子显微镜（TEM）,扫描电子显微镜（SEM）,X射线衍射仪（XRD）,X射线光电子衍射仪（XPS）和振动样品磁强计（VSM）五种仪器进行了不同的表征,从而进一步确定了MC-PDA-Ag复合催化材料的成功制备。催化还原试验证实了,MC-PDA-Ag复合催化材料在NaBH₄存在下能够对三种模型染料（MB,RhB和MO）显示出优异的催化性能,但对每种模型染料的催化效果又有差异性。同时,还比较了无还原剂参与情况下,三种复合材料对MB染料的吸附性能,证明了MC-PDA-Ag复合材料的吸附性能没有催化性能优越。另外,还将MC-PDA-Ag与其他报道的催化剂进行对比,发现MC-PDA-Ag催化剂的催化性能最佳。在不同的初始溶液pH（3-11）和不同的NaNO₃浓度（0-0.5 M）下,MC-PDA-Ag催化还原MB的反应发生5分钟后,其催化效率依然超过90%,表明MC-PDA-Ag催化剂在染料废水的处理中具有潜在的普遍适应性。此外,MC-PDA-Ag经过5次循环使用后,观察到它的催化能力没有明显降低,并且该催化剂可以通过外部磁体被分离,表明制备的MC-PDA-Ag催化剂具有高的可重复使用性和易分离性。这些结果共同表明MC-PDA-Ag复合材料可以作为还原有机染料的有效催化剂被使用,在废水处理中具有很大的应用潜力。更多还原

【Abstract】 With the rapid development of industry,many organic pollutants are unintentionally released into the water body,especially the discharge of dye wastewater cause serious damage to the water environment and the ecological environment.In order to treat contaminated water bodies,many methods have been researched and developed,and the catalytic reduction for organic dyes using a catalyst has been strongly promoted.In order to explore efficient,economical,and environmentally friendly catalysts,Ag nanoparticles loaded on polydopamine coated magnetic biochar（MC-PDA-Ag）catalyst was prepared by in-situ reduction approach in this study.The surface morphology,elemental composition,and chemical structure of MC-PDA-Ag composites were characterized by the transmission electron microscopy（TEM）,the scanning electron microscope（SEM）,X-ray diffractometer（XRD）,X-ray photoelectron spectroscopy（XPS）,and vibrating sample magnetometer（VSM）,and the characterization results further confirmed the successful preparation of MC-PDA-Ag composite catalyst.Catalytic reduction tests confirmed that MC-PDA-Ag catalyst exhibited excellent catalytic performance on the model dyes（MB,RhB,and MO）in the presence of NaBH₄,but the catalytic effects of each model dye were different.At the same time,the adsorption performance of three composites on MB dyes was compared in the absence of reducing agent,and it was proved that the adsorption performance of MC-PDA-Ag was not as good as its catalytic performance.In addition,MC-PDA-Ag was compared with other reported catalysts,and it was found that the MC-PDA-Ag catalyst has excellent catalytic performance.The reduction efficiency of MB exceeded 90%by MC-PDA-Ag even under different initial pH（3-11）and different NaNO₃ concentrations（0-0.5 M）within 5 min,indicating that the MC-PDA-Ag catalyst has potential strong universal adaptability in dye wastewater treatment.Furthermore,no significant decrease in catalytic ability was observed after 5recycles,and the catalyst can be separated by an external magnet,indicating that this as-prepared catalyst exhibited high reusability and easy separability.These results collectively suggest that MC-PDA-Ag composites can be used as an efficient catalyst for the reduction of organic dyes,and have great potential for application in wastewater treatment.更多还原