海绵铁对不同种类偶氮染料脱色性能及其动力学研究

Study on the Kinetics and Deocolorization Performance of Different Azo Dyes by Sponge Iron

系统考察了不同脱色条件下海绵铁对偶氮染料的脱色性能及其动力学。研究结果表明,脱色时间在0~40min内海绵铁对酸性媒介黑T、直接兰2B、直接橙S、活性黄X-R和阳离子红X-GRL的脱色率随着脱色时间增加而增加,且脱色反应符合一级反应动力学方程。偶氮染料的脱色率和脱色反应速率常数(k_(obs))随着海绵铁粒径的增大而降低,但是随着海绵铁投加量和反应温度的增加而增大。海绵铁对不同偶氮染料的脱色率和脱色k_(obs)随着pH升高而逐渐降低。由于不同偶氮染料的物理性质、化学性质和化学结构存在差异,海绵铁对不同种类偶氮染料的脱色率和脱色k_(obs)是不同的。

The decolorizaiton performance and kinetics of different azo dyes by sponge iron were investi- gated at different decolorizaiton conditions. The decolorization efficiencies of acid chrome black T, direct blue, direct orange S, reactive yellow X-R and cationic red X-GRL by sponge iron increased with the in- crease of decolorization time from 0 to 40 min, and the decolorization reactions of azo dyes by sponge iron were in accord with first-order reaction kinetic equation. The decolorization efficiency and decolorization reaction rate constant （kobs）of azo dyes by sponge iron decreased with the increase of particle size and in- creased with the increase of reaction temperature and sponge iron dose. The decolorization efficiency and decolorization kobs Of azo dyes by sponge iron decreased with the increase of pH. Due to the difference of physical property, chemical property and chemical constitution, the decolorization efficiency and decolori- zation kobs, of different azo dyes by sponge iron were different at different decolorization conditions.