EDTA催化Fe3+/H2O2降解水中孔雀石绿

以孔雀石绿(malachite green, MG)为目标物,在pH=7的中性条件下,考察EDTA对Fe3 /H2O2降解水中孔雀石绿的影响,发现EDTA很大程度地促进了Fe3 /H2O2对孔雀石绿的降解. EDRA的加入可以使MG的脱色率由43%升至98.3%.在本实验条件下, EDTA的投加量增加5倍时, MG的脱色率上升40%.随着H2O2投量的增加, MG的脱色率显著上升.随着温度的升高, MG的脱色率显著上升.叔丁醇的加入抑制了EDTA对Fe3 /H2O2降解孔雀石绿的催化效果.总量相同H2O2的多次投加并未获得明显优于一次投加的去除效果. EDTA催化Fe3 /H2O2降解水中孔雀石绿并不遵循简单的羟基自由基机理,同时存在的中间价态铁的物种起着主要的氧化作用.随着反应的进行, EDTA被部分降解.

Degradation of malachite green in aqueous solution by Fe3+/H2O2 catalyzed with EDTA

This study found that the discolorization of Malachite green solutions (0.01mmol/L) was improved by Fe3+/H2O2 catalyzed with EDTA, at pH 7. Oxidation is carried out in presence of various hydrogen peroxide concentrations, in a wide range of temperature and EDTA concentration. It was found that oxidation with EDTA promoted the discolorization of MG from 43% to 98.3% as compared with the cases without EDTA. In this study, the discolorization of MG increased by 40% with the increase of EDTA concentration by 5 fold. The H2O2 concentration and temperature are higher, the discolorization of MG better. t-BuOH inhibited the improvement from EDTA. With the same total dosage of applied H2O2, the multiple steps addition did not show a much higher removal efficiency than that obtained by one step. OH free radical or an iron-oxo species may be the highly reactive oxidizing species, the latter may be the major oxidant. With the time, EDTA was a little oxidized.