The application of chromium substituted magnetite as heterogeneous Fenton catalyst for the degradation of aqueous cationic and anionic dyes
The application of chromium substituted magnetite as heterogeneous Fenton catalyst for the degradation of aqueous cationic and anionic dyes
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铬取代磁铁矿作为多相芬顿催化剂降解水性阳离子和阴离子染料的应用
DOI：
10.1016/j.cej.2012.03.001
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发表时间：
2012-05-15
影响因子：
15.1
通讯作者：
Jiang, Zheng
中科院分区：
文献类型：
--
作者：
Liang, Xiaoliang;Zhong, Yuanhong;Jiang, Zheng
在中性pH条件下，研究了一系列含铬磁铁矿（Fe 3-xCrxO 4，x=0.00，0.18，0.33，0.47和0.67）催化的非均相芬顿降解阳离子和阴离子染料的反应。选择亚甲基蓝（MB）和酸性橙子II（AOII）作为阳离子和阴离子污染物的模型。重点比较了MB和AOII的降解特性以及Cr取代对两种染料降解效率的影响。Cr ~（3+）的八面体占据增加了磁铁矿的比表面积和表面羟基含量，从而提高了磁铁矿对亚甲基蓝的吸附能力。然而，这些含铬磁铁矿显示没有吸附AOII。MB的降解遵循Langmuir-Hinshelwood模型，符合零级动力学方程，AOII的降解遵循Eley-Rideal模型，符合两阶段准一级动力学方程。Cr的掺入显著提高了磁铁矿在非均相芬顿反应中的催化活性，但提高的程度因取代度而异。这些新的见解是非常重要的环境应用的金属取代磁铁矿在净化纺织废水。(C)2012爱思唯尔有限公司版权所有。
In this study, the heterogeneous Fenton degradation of cationic and anionic dyes catalyzed by a series of Cr-containing magnetites (Fe3-xCrxO4, x=0.00, 0.18, 0.33, 0.47 and 0.67) has been investigated under neutral pH conditions. Methylene blue (MB) and acid orange II (AOII) were chosen as models of cationic and anionic contaminants. Emphases were laid on the comparison of degradation characteristic between MB and AOII and the effect of Cr substitution on the degradation efficiency of both dyes. The octahedral occupancy of Cr3+ increased the BET surface area and superficial hydroxyl amount of magnetite, resulting in an improvement of adsorption ability of MB. However, these Cr-containing magnetites showed no adsorption to AOII. The MB degradation, following the Langmuir-Hinshelwood model, was well fitted by zero-order equation while AOII degradation following the Eley-Rideal model, was well fitted with two-stage pseudo-first-order kinetics. The Cr incorporation significantly improved the catalytic activity of magnetite in heterogeneous Fenton reaction, but the extent of improvement varied with the substitution level. These new insights are of high importance for the environmental application of metal substituted magnetites in the purification of textile wastewater. (C) 2012 Elsevier B.V. All rights reserved.