树脂负载草酸铁光助类芬顿降解水中孔雀石绿

Photo-assisted Degradation of Dye Malachite Green Solution over Fe^(3+) C_2O_4-Loaded Resin in the Presence of H_2O_2

为了强化多相类芬顿反应的速率,在可见光下采用以草酸盐为配体的三价铁草酸络合物(Fe3+C2O4/R)为催化剂催化过氧化氢降解水中孔雀石绿.结果表明,与Fe3+/R相比催化剂Fe3+C2O4/R具有更强的催化活性,能强化羟基自由基(.OH)的产生.过氧化氢的初始浓度越高,反应速率越快,反应遵循一级反应动力学,反应速率常数与过氧化氢浓度具有很好的相关性.在pH值3~9的范围内,催化剂Fe3+C2O4/R都能有效地对MG进行降解,最佳pH值为6.随着催化剂投量的增加,MG的去除效率明显提高.随着MG初始浓度的增加,MG的去除也由吸附为主转化为以氧化为主,但总体影响不大.催化剂重复使用后仍然具有较好的催化活性,说明铁在树脂表面负载比较牢固,催化剂具有反复使用的能力.反应中的氧化活性物种是羟基自由基和高价态铁同时共存.

In order to increase the reaction rate of the heterogeneous Fenton-like oxidation, the catalyst of Fe^3＋C2O4/R was used to catalytically decompose H2O2 for the removal of malachite green （MG） in aqueous solution under the visible light irradiation condition. The results show that the catalyst of Fe^3＋C2O4/R has a better catalytic reactivity to enhance the formation of ·OH compared with that of Fe3 ~/R. The higher the concentration of H2 02, the faster the reaction rate is. This reaction follows pseudo-first-order kinetics, the reaction rate constant has a good relativity with the concentration of H202. The catalyst of Fe^3＋C2O4/R could decompose H2O2 to degrade MG effectively at pH 3-9, the optimum pH is 6. The removal rate of MG increased with the increase of the dosage of catalyst. With the increase of the concentration of MG, the removal of MG by the adsorption turned to be by the oxidation. Repeated uses of catalyst did not decrease the removal rate of MG. The ferryl and hydroxyl radicals are both the reactive species in the oxidation of MG.