蛋白土-Fe_2O_3非均相Fenton催化剂高效降解罗丹明B染料废水

Research on opal-Fe_2O_3 as a heterogeneous Fenton catalyst for degrading the Rhodamine B dye wastewater

采用共沉淀法将Fe_2O_3负载于蛋白土表面,制备出一种新型、高效的非均相光-Fenton催化剂,并将其用于降解罗丹明B染料废水,取得显著效果。利用N_2吸附、X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱分析仪(EDS)、傅里叶红外光谱(FTIR)等方法对复合材料的结构进行了表征。考察了废水中COD去除率及影响降解效果的因素,包括溶液pH、反应温度、催化剂投加量、H_2O_2投加量以及罗丹明B的初始浓度等。试验结果显示,在可见光照射下、pH=2.5、反应温度30℃、催化剂投加量0.15g/L、H_2O_2投加量9.0mmol/L、罗丹明B初始浓度40mg/L的条件下磁力搅拌120min,罗丹明B溶液脱色率达到96.49%,COD去除率达到50.51%。对反应过程进行了一级动力学方程拟合,在最佳反应条件下R^2=0.98,说明该反应过程属于一级动力学反应。催化剂循环使用5次后,对罗丹明B的脱色率仍能达到85%以上,证明该催化剂具有良好的循环性能。最后,对反应过程进行了分析,提出了一种可能的反应机理。

A novel and efficient heterogeneous photo-Fenton catalyst has been successfully prepared using co-precipitation method,in which the Fe2O3particles were loaded onto the surface of opal.Thecatalyst was then used to degrade the Rhodamine B(RhB).The structural characterization of catalyst was analyzed by N2adsorption,X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),Fourier transform infrared spectroscopy(FTIR).The COD(chemical oxygen demand)removal and the influencing factors of degradation effect were analyzed,such as pH,temperature,catalyst dosage,H2O2dosage and initial dye concentration.The results showed that the decolorization rate of RhB and COD removal were96.49%and50.51%respectively under agitation after120min treatment with pH of2.5,reaction temperature30℃,dosage of catalyst0.15g/L,dosage of H2O29.0mmol/L and initial concentration of RhB40.0mg/L.The first-order kinetic equation was fitted to the reaction process,and R2=0.98under the optimal condition,which indicated that the reaction process obeys the first-order kinetic equation.The decolorization rate of RhB was still higher than85%when the catalyst used for5times,which proved that the catalyst has a good reusability.Finally,the reaction process was analyzed and a possible photocatalytic mec hanism was proposed.