铁基蒙脱土异相光助芬顿催化降解活性黑5的性能研究

Fe-montmorillonite As a Heterogeneous Photo-Fenton Catalyst for the Degradation of Reactive Black 5

采用离子交换法制备了铁基蒙脱土(Fe-MMT),运用傅里叶变换红外光谱(FT-IR)和X-射线衍射(XRD)对其结构进行表征。利用Fe-MMT构建异相光助芬顿体系,考察了反应条件对活性黑5(RB5)脱色和苯环降解性能的影响。结果表明,光照明显提高了Fe-MMT构建的芬顿体系对RB5的脱色和苯环降解性能。脱色反应进行30 min后,开始发生苯环的降解反应。以1.0倍MMT离子交换容量的Fe(III)制备的Fe-MMT为催化剂,在投加量0.02 g,RB5浓度100 mg/L,pH为3,H2O2浓度2 mmol/L的条件下,反应240 min后,RB5的脱色率可达99.8%,苯环降解率可达91.4%。RB5的脱色过程符合准一级动力学模型,而苯环降解过程更符合准二级动力学模型。催化剂连续循环使用4次后,对RB5的脱色率仍达99.8%,苯环降解率为87.6%,表明催化剂具有良好的重复使用性能。

Fe(III)-exchanged montmorillonites(Fe-MMT)were prepared and characterized by Fourier Transform Infrared Spectroscopy(FT-IR)and X-ray diffraction(XRD).Fe-MMT was studied as heterogeneous catalyst of photo-Fenton like oxidation of Reactive Black 5(RB5).A detailed experimental study was carried out to investigate the effects of operating parameters on the decolorization and degradation of RB5.The results indicated that the efficiency towards decolorization and degradation of RB5 was enhanced as the Fenton process was coupled with solar light illumination.The degradation reaction of benzene ring started after the decolorization reaction carried for 30 minutes.The optimal operating parameters were determined as pH 3,initial concentration of RB5100 mg/L,H2O22 mmol/L using 0.02 g Fe-MMT,which prepared as Fe(III)amount to the exchange capacity of MMT 1.0 times,for 240 min.The decolorization and degradation rate of RB5 reached to 99.8%and 91.4%,respectively.The decolorization reaction of RB5 was found to fit into the pseudo first-order kinetic model,while the degradation reaction was best agreement with the pseudo second-order kinetic model.The decolorization and degradation rate maintained 99.8%and 87.6%after four times consecutive catalysis,which confirmed the excellent cycling performance of Fe-MMT.