Electro-Fenton Process Catalyzed by Fe3O4 Magnetic Nanoparticles for Degradation of C.I. Reactive Blue 19 in Aqueous Solution: Operating Conditions, Influence, and Mechanism

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• 作者：Zhiqiao He ; Chao Gao ; Mengqian Qian ; Yuanqiao Shi ; Jianmeng Chen ; Shuang Song
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：March 5, 2014
• 年：2014
• 卷：53
• 期：9
• 页码：3435-3447
• 全文大小：663K
• 年卷期：v.53,no.9(March 5, 2014)
• ISSN：1520-5045

文摘

Fe₃O₄ magnetic nanoparticles (MNPs) were employed for electro-Fenton (Fe₃O₄鈥揺lectro-Fenton) degradation of C.I. Reactive Blue 19 (RB19) in an undivided electrochemical reactor with an activated carbon fiber felt cathode and a platinum anode. On the basis of physicochemical characterization of the Fe₃O₄ MNPs as well as quantitative measurements of iron leaching and H₂O₂ generation, it is concluded that the Fe₃O₄ MNPs facilitated the decomposition of H₂O₂ to generate hydroxyl radicals (鈥H). Moreover, the cathodic electro-Fenton facilitated electro-regeneration of ferrous ion and maintained continuous supply of H₂O₂. The effect of several operational parameters such as pH, current density, amount of added Fe₃O₄ MNPs, initial RB19 concentration, and temperature on the removal of total organic carbon was investigated. It was found that the Fe₃O₄鈥揺lectro-Fenton degradation of RB19 followed two-stage first-order kinetics with an induction period and a rapid degradation stage. Mineralization of RB19 proceeded rapidly only at pH 3.0. Increasing the current density and the dosage of Fe₃O₄ MNPs enhanced the rate of RB19 degradation. However, higher current densities and Fe₃O₄ dosages inhibited the reaction. The rate of RB19 degradation decreased with the increase in initial RB19 concentration and increased with the increase in temperature. The removal efficiency of total organic carbon reached 87.0% after 120 min of electrolysis at an initial pH of 3.0, current density of 3.0 mA/cm², 1.0 g/L concentration of added Fe₃O₄ MNPs, 100 mg/L initial dye concentration, and 35 掳C temperature. On the basis of the analytical results for the intermediate products and the assumption that 鈥H radicals are the major reactive species, we propose a possible pathway of RB19 degradation during the cathodic electro-Fenton process using Fe₃O₄ MNPs as iron source.