Study on the Degradation of Azo Dye Wastewater by Zero-valent Iron

摘要

Wastewater from fabric and yarn dyeing impose serious environmental problems because of their colour and potential toxicity. The release of coloured wastewaters in ecosystems is a dramatic source of aesthetic pollution, eutrophication and perturbations in aquatic life. The most common group of commercial dyes used in the textile industries is azo dyes. The degradation of azo dye wastewater by zero-valent iron was investigated. The dye of C.I. Reactive Red 15 was chosen as object in the experiment. The effects of the dosage of zero-valent iron, pH in solution, reaction time and the initial azo dye concentration on the decolorization were studied in detail. The results showed that the pH value, the dosage of zero-valent iron and the initial azo dye concentration had an important impact on azo dye decolorization. High decolorization efficiency of azo dye wastewater by zero-valent iron was achieved under the optimal condition. The zero-valent iron was also proved to be a universal and efficient reductant for rapid decolorization of the azo dye wastewater. This method can be applied into the treatment of the azo dye wastewater.