Novel bentonite clay-based Fe-nanocomposite as a heterogeneous catalyst for photo-fenton discoloration and mineralization of orange II
Novel bentonite clay-based Fe-nanocomposite as a heterogeneous catalyst for photo-fenton discoloration and mineralization of orange II
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DOI：
10.1021/es034515c
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发表时间：
2004-01-01
影响因子：
11.4
通讯作者：
Yue, PL
中科院分区：
文献类型：
--
作者：
Feng, J;Hu, XJ;Yue, PL
研制了一种新型膨润土基铁纳米复合材料(Fe-B)，用于偶氮染料Orange II的光-Fenton变色和矿化反应。X射线衍射(XRD)分析表明，Fe-B纳米复合催化剂主要由Fe2O_3(赤铁矿)和SiO_2(石英)微晶组成，X-反射荧光(XRF)测定Fe-B催化剂的Fe含量为31.8wt%。在H_2O_2和紫外光(254 Nm)存在下，考察了Fe-B对橙色11的变色和矿化的催化活性。结果表明，Fe-B催化剂的最佳用量为1.0g/L左右，且随着橙黄11初始浓度的降低或反应温度的升高，橙11的变色和矿化效率增加。在最佳条件下(10 mM H_2O_2，1.0g铁-B/L，1×8W UVC，pH=3.0)，0.2 mm橙黄II的完全变色和矿化时间分别不到60min和120min。结果表明，Fe-B纳米复合催化剂不仅对橙黄11的光Fenton变色反应具有很高的催化活性，而且对橙黄II的矿化也表现出很高的催化活性。反应动力学分析表明，橙色11在前15分钟的光Fenton变色反应符合准一级动力学。计算的反应活化能为9.94kJ/mol，表明Orange II的Fenton变色对反应温度不是很敏感。
A novel bentonite clay-based Fe-nanocomposite (Fe-B) was successfully developed as a heterogeneous catalyst for photo-Fenton discoloration and mineralization of an azodye Orange II. X-ray diffraction (XRD) analysis clearly reveals that the Fe-B nanocomposite catalyst mainly consists of Fe2O3 (hematite) and SiO2 (quartz) crystallites, and the Fe concentration of the Fe-B catalyst determined by X-reflective fluorescence (XRF) is 31.8 wt %. The catalytic activity of the Fe-B was evaluated in the discoloration and mineralization of Orange 11 in the presence of H2O2 and UVC light (254 nm). It was found that the optimal Fe-B catalyst dosage is around 1.0 g/L, and the efficiency of discoloration and mineralization of Orange 11 increases as initial Orange 11 concentration decreases or reaction temperature increases. In addition, at optimal conditions (10 mM H2O2, 1.0 g of Fe-B/L, 1 x 8W UVC, and pH = 3.0), complete discoloration and mineralization of 0.2 mM Orange II can be achieved in less than 60 and 120 min, respectively. The result strongly indicates that the Fe-B nanocomposite catalyst exhibits a high catalytic activity not only in the photo-Fenton discoloration of Orange 11 but also in the mineralization of Orange II. The reaction kinetics analysis illustrates that the photo-Fenton discoloration of Orange 11 in the first 15 min obeys the pseudo-first-order kinetics. The reaction activation energy calculated was 9.94 kJ/mol, indicating that the photo-Fenton discoloration of Orange II is not very sensitive to reaction temperature.