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With the rapid development of society and the improvement of the level of industrialization, which to bring huge economic benefits for human, but also to have serious effect on human’s living environment. Water pollution in these environmental problems was the most prominent. Polluter of water bodies were mainly wastewater discharged by industrial production, in particular, the wastewater discharged by printing and dyeing industry. Most of these synthetic dyes have complex aromatic structures; the complex aromatic molecular structures of dyes make them more stable and more difficult to biodegrade. Synthetic dyes have been increasingly used in the textile, leather, paper, rubber, plastics, cosmetics, pharmaceutical and food industries. The extensive use of dyes often poses pollution problems in the form of colored wastewater discharged into environmental water bodies, which lead to the pollution of natural water. For that reason, the wastewater discharge must be effective treatment prior to discharge into the water body. In this thesis, the aqueous solution of alizarin red dye as analogue dye wastewater, its treatment was researched by adsorption, electrochemical oxidation and adsorption cooperated with electrochemical method.In the fist part, first the type and nature of dyes and use of dyes were introduced, respectively. Then analysis of the pollution caused by the dye and its hazards, and illustrated that dyeing wastewater brought benefits to mankind, but also it created hazards to the survival of human and environmental. And status of printing and dyeing wastewater treatment were reviewed in detail, including physical, chemical and biological treatment methods of printing and dyeing wastewater, in special, emphasized the nature and current treatment status for alizarin red dye, and activated clay application in dyeing wastewater. Finally, we presented the purpose, content and innovation of this study.In the second part, it mainly introduced the preparation of an inexpensive adsorbent—modified activated clay, and the characterization of the prepared adsorbents was performed using physical adsorption analyzer, X-ray diffraction (XRD) instrument, environmental scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), fourier transform infrared spectroscopy (FT-IR) and other analytical methods. The experimental results show that the prepared modified activated clay can remove more than 98% of alizarin red S dye, COD removal rate can reach 80% and solution of pH about 6.8 under optimum operational conditions of a dose of adsorbent 16 g/L, pH 3.05 and a contact time of 60 min for initial dye concentrations of 400 mg/L. Treated wastewater can reach the first grade level of wastewater discharge standards.In the third part, it mainly introduced the electrochemical oxidation of anthraquinone dye Alizarin Red S wastewater assisted by sulfuric acid modified activated clay in a 500 ml electrolytic batch reactor with graphite plate as anode and titanium net as cathode was investigated. The effects of initial pH, applied voltage, electrolyte type, ventilation, and the initial dye concentration on decolorization of Alizarin Red S were discussed. From the results it can be found that when the initial pH was at 3, dye concentration of 200 mg/L; sodium chloride electrolyte was 3 g/L; cell voltage was 10 V; catalyst dose was 20 g/L; ventilation was 100 L/h, decolorizing rate could reach up to 97.1% in 50 min.In the fourth part, removal of alizarin red dye wastewater using the low-cost adsorbent combined with the electrochemical method was introduced. By univariate analysis of factors, to determine the main factors which influenced the experimental were four, namely:the initial dye solution pH, cell voltage, adsorbent dosage, electrolysis quality. Then, factors which affected water removal, each of which was tested at four levels by range and variance analysis using the orthogonal design method, and to optimize the best wastewater treatment process.
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