CoFeMg氧化物纳米晶Fenton-降解亚甲基蓝的反应动力学

采用溶胶-凝胶法制备CoFeMg氧化物纳米晶,并用扫描电子显微镜(SEM)和X射线衍射(XRD)表征样品形貌,考察亚甲基蓝催化剂与H2O2的协同降解作用.采用稳态近似法研究氧化降解亚甲基蓝的动力学过程.结果表明:CoFeMg氧化物纳米晶和H2O2组成的Fenton反应体系可有效降解亚甲基蓝,当催化剂和H2O2的加入量分别为0.8g/L和2mmol/L,初始pH≈7.15时,亚甲基蓝的降解率为95%;与传统的Fenton反应体系相比,溶出铁的质量浓度降低为0.2mg/L;Fenton反应是羟基自由基(·OH)氧化降解有机物的过程,其反应可近似为二级动力学反应.

Reaction Kinetics of CoFeMg Oxide Nano Particles Fenton-Degraded Methylene Blue

CoFeMg oxide nanocrystals were prepared with sol gel method and characterized as a catalyst. SEM and XRD were used to characterize thecatalyst, methylene blue was used to study the synergistic degradation of the catalyst and H₂O₂, the dynamic process of oxidative degradation of methylene
blue was studied by the steady state approximation method. Results show that CoFeMg Fenton reaction system composed of CoFeMg oxide nanocrystals used as a heterogeneous Fenton like catalyst and H₂O₂ effectively degraded methylene blue. At pH≈7.15, a mass concentration of CoFeMg oxide nanocrystals of 0.8 g/L and concentration of H₂O₂ of 2 mmol/L, the degradation rate of methylene blue was evaluated to be 95%. Compared with that of traditional Fenton reaction system, the amount of leaching of iron was decreased to 0.2 mg/L under similar conditions. Thedynamics results show that Fenton reaction system shows a hydroxyl radicals (·OH) oxidation degradation process of methylene blue, and the reaction was considered as secondary dynamics.