醌基陶粒强化偶氮染料化学脱色的特性研究

Enhanced Chemical Decolorization of Azo Dyes by Using AQS Immobilized on Ceramsites

采用吸附/共价耦合的方法将氧化还原介体蒽醌-2-磺酸(AQS)固定在无机陶粒表面(醌基陶粒),并对其在无氧条件下强化偶氮染料的化学脱色特性进行了研究。研究结果表明,AQS能够被固定在无机陶粒上,其浓度为2.3μmol g 1;在无氧条件下,醌基陶粒强化酸性金黄G化学脱色的最佳条件为:Na2S浓度为3.2 mmol L 1,pH为6.0;整个反应过程遵循假一级反应动力学,并且随着固定化AQS浓度的增加,酸性金黄G的假一阶动力学常数明显增大。当加入60μmol L 1固态醌时,酸性金黄G、活性艳红X-3B、苋菜红和酸性橙7的假一阶动力学常数分别提高2.9、5.3、9.9和6.0倍,并且重复实验表明,醌基陶粒介导的偶氮染料脱色速率能够保持为最初的98%。由此可见,此种新型的固定化介体材料醌基陶粒在偶氮染料废水处理方面具有潜在的应用价值。

Anthraquionne-2-sulfonate （AQS） was immobilized on the surface of cerarnsites to form AQS-ceramsites by using adsorption/covalence coupling method, and its catalytic performance on the chemical decolorization of azo dyes was investigated in the absence of oxygen. The results show that AQS could be immobilized on the ceramsites, and the concentration of immobilized AQS is 2.3 μmol.g-1. The optimal conditions for AQS-ceramsites mediated decolorization of Acid Yellow G were found to be 3.2 mmol.L-1 Na2S and pH 6.0. Under the above optimal conditions, its decolorization kinetics could be described by using a pseudo first-order equation. Moreover, with the increase of the concentration of the immobilized AQS, the pseudo-first-order rate constant of the decolorization of Acid Yellow G obviously increases. In the presence of 60 μmol.L-1 immobilized AQS, the rate constants of the decolorization of Acid Yellow G, Reactive Red X-3B, Amaranth and Acid Orange 7 increase respectivety 2.9, 5.3, 9.9 and 6.0 fold higher than those without using AQS-ceramsites. Furthermore, experiments with repeated used AQS-ceramsites show that their decolorization efficiencies of azo dyes could remain over 98% of their original value. These studies indicate that the novel immobilized AQS as redox mediators has potential applications in the treatment of azo dyes wastewater.