Mn-Mg-Ce/AC催化臭氧氧化降解水中苯酚的研究

Degradation of phenol in aqueous solution by Mn-Mg-Ce/AC catalytic ozonation

采用共沉淀法制备Mn-Mg-Ce/AC催化剂,并研究了其在苯酚废水降解过程中的性能和作用机理。利用XRD、FT-IR、SEM、EDS对催化剂的结构、形貌及组成进行表征,并考察了苯酚降解的最佳反应条件及其反应动力学。结果表明,催化剂表面金属氧化物负载均匀、催化效果好。当催化剂的质量浓度为2.5 g/L、溶液初始苯酚质量浓度为450 mg/L时,在较大pH范围内催化效果良好,苯酚去除率达到了99%以上,COD去除率达到了92%。该催化臭氧氧化反应动力学均为准一级反应,并用一系列自由基捕获的方法探究了降解反应机理,结果发现反应活性氧自由基(·OH、·O、~1O)参与了苯酚的降解。

Mn-Mg-Ce/AC catalyst is prepared via co-precipitation method,and its performance and action mechanism in the degradation process of phenol wastewater are studied.Various characterization methods,such as XRD,FT-IR,SEM and EDS,are employed to characterize the structure,morphology and composition of the catalyst.The optimal reaction conditions and kinetics for degradation of phenol are investigated.The result shows that metal oxides are uniformly supported on the surface of the catalyst.The removal rates of phenol and COD exceed 99%and 92%,respectively when the dosage of catalyst is 2.5 g,the initial concentration of phenol is 450 mg·L^(-1) and the initial pH of solution is 5.8.It is reasonable that the reaction kinetic can be divided into two stages,which follows two parallel pseudo-first-order reaction.The degradation mechanism is investigated through a series of free radical capture method,and it is found that·OH,·O,and~1Oare mainly responsible for phenol degradation.