偶氮染料的光还原脱色及其染色废水的回用研究

Decoloration of azo dyes by photo-reduction and the reuse of dyeing effluence

用还原脱色剂对水溶性偶氮染料进行光还原脱色降解,重点考察了还原脱色剂、辐射光以及染料浓度等对还原脱色反应的影响,并将脱色后的染色废水回用于棉织物染色中。结果表明,以适当比例的引发剂和促进剂组成的还原脱色剂具有较强的脱色降解能力,辐射光对染料的还原脱色反应具有明显的促进作用,染料浓度的提高不利于染料的脱色降解反应。脱色废水可以回用于棉织物的活性染料染色中,通过降低染色过程中氯化钠和碳酸钠的添加量,可使染色试样与自来水染色试样的总色差(DE*)<1.0。

The photo-reduction decoloration of two water-soluble azo dyes in water has been carried out with reducing agent based on promoter and inducer. A few factors affecting the decoloration such as, reducing agent, irradiation and dye concentration are e^amined with respect to decoloration efficiency. The spent dyebath water is decolorized and used for the dyeing of cotton fabrics with reactive dyes. The results indicate that reducing agent containing an appropriate proportion of promoter to inducer shows higher power of decoloration. Also the decoloration of the dyes could be improved significantly by irradiation. Decreasing the initial concentration of dyes enhanced the decoloration. In addition, decolorized dyeing effluent is available in the dyeing of cotton fabrics with reactive dyes, The color difference （DE^＊） between cotton fabrics dyed in fresh tap water and the decolorized dyeing effluent is less than 1.0, when the dosages of sodium chloride and sodium carbonate are decreased in the process of dyeing.