MnFe_2O_4的合成及其非均相Fenton法降解工业废水的性能

Systhesis of MnFe_2O_4 and its degradation of industrial wastewater by heterogeneous Fenton method

采用水热合成法制备了尖晶石铁氧体Mn Fe_2O_4磁性纳米催化剂,通过XRD、SEM、TEM、BET、TG/DTA等对其物相结构进行表征,并通过降解亚甲基蓝、罗丹明B和苯酚作为探针反应行了活性测试。结果表明,在反应溶液体系p H=7、催化剂加入量0.5g/L、过氧化氢浓度1.25mmol/L、反应温度20℃时,亚甲基蓝、罗丹明B、苯酚的降解率在130min内分别达到了97.34%、94.48%、16.63%。反应体系引入超声辅助后50min内亚甲基蓝降解率为95.61%,高于单一非均相Fenton催化体系50min内对其80%的降解率,表明超声空化与非均相Fenton反应之间具有协同效应,有助于提高反应物降解率。活性中心鉴定表明高价铁氧体为染料降解的主要活性中心,而羟基自由基则是苯酚降解的主要活性中心。循环测试实验表明,催化剂活性高、稳定性高、可再生、不易溶出失活。

Spinel ferrite MnFe2O4 magnetic nano catalysts were prepared through hydrothermal synthesis.Their morphology and structure were characterized by XRD,SEM,TEM,BET and TG/DTA.Methylene blue（MB）,Rhodamine B and phenol were selected as the degradation object for activity test.The results showed that when the reaction conditions were 0.5g/L catalyst and1.25mmol/L H2O2,20℃and p H=7,the degradation rate of MB,Rhodamine B,phenol reached97.34%,94.48%and 16.63%respectively in 130 minutes.Moreover,the degradation rate of MB was increased to 95.61%within 50min with the introduction of ultrasound,which was higher than that of the sole heterogeneous Fenton reaction system,indicating the synergistic effect between ultrasonic cavitation and heterogeneous Fenton reaction.The identification of active center revealed that high valence ferrite is the main active substance of the dye degradation system,whereas the hydroxyl free radical is the most important for phenol degradation.Recycle tests showed that the catalysts had high activity,good stability and excellent renewable capacity.