Treatment Of Anthraquinone Dye Wastewater By Process Of Fe/C Electrolysis-Fenton Synergistic Oxidation-coagulation Sedimentation-Anaerobic-Aerobic

Anthraquinone disperse dyes are widely used in textile printing and dyeing industry,with its bright color and high fastness.Because of the high chroma,large amounts of refractory organic pollutants and poor biodegradability,the dye wastewater was difficult to be treated by biochemical technology directly.Besides,this kind of wastewater will destroy the aquatic ecosystem and even cause serious problems of water environment if it discharged directly into the water did not reach the required standard.In this study,the process of Fe/C micro electrolytic-Fenton synergistic oxidation,coagulation sedimentation and anaerobic-aerobic was used to treat anthraquinone dye wastewater.In order to ensure the final effluent could reach the discharge standard,a series of experiments was used to determine the appropriate operating parameters.Obtain the following results:（1）The process of Fe/C micro electrolytic-Fenton synergistic oxidation can reduce the chroma and the concentration of organic pollutants in wastewater effectively,also improve the biodegradability of wastewater significantly.The order of influence of each factor on reducing COD was that:pH>the dosage of H₂O₂>the dosage of Fe/C>reaction time.The appropriate reaction conditions in this unit were that:initial pH was 3.5,the dosage of H₂O₂ was 3ml/L,the dosage of Fe/C was 300g/L,the reaction time was 100 min.Under aeration conditions,the removal rates of COD and colority could reach more than 55% and 85%,respectively.（2）In the coagulation sedimentation unit,the order of influence of each factor on reducing COD was that:pH>the dosage of effective Al₂O₃>sedimentation time>the dosage of PAM.The appropriate reaction conditions in this unit were that:initial pH was 7,the dosage of effective Al₂O₃ was 400mg/L,the dosage of PAM was 3mg/L,sedimentation time was 30 min.Under these conditions,the effluent concentration of COD was about 800¹000mg/L and the removal rate up to 60%,the effluent of chroma was about 200³00times and the removal rate up to 80%,the value of BOD5/COD was about 0.35.（3）Anaerobic and aerobic reactor takes 40 days and 32 days respectively to complete the activation.The appropriate reaction conditions in anaerobic reactor were that:initial pH was 7,the hydraulic retention time was 72 h,the temperature was 33³5℃.The appropriate reaction conditions in aerobic reactor were that:initial pH was 7,the hydraulic retention time was 24 h,the concentration of dissolved oxygenwas 3⁵mg/L,the temperature was 33³5℃.Run for 30 days continuously under the appropriate condition of anaerobic and aerobic reactor.The experimental results show that,anaerobic-aerobic system was stable,the effluent concentration of COD was139¹78mg/L and the removal rate up to 80%,the effluent of chroma was65⁷0times and the removal rate up to 70%,the effluent concentration of （NH₄）⁺ -N,TN,TP were 8.13¹1.64mg/L,22.87²7.31mg/L and 0.74¹.27mg/L,respectively.（4）Through the treatment of Fe/C micro electrolytic-Fenton synergistic oxidation,coagulation sedimentation and anaerobic-aerobic,the water quality indicators of anthraquinone disperse dye wastewater could reach the indirect discharge standards of Water Pollutants for Textile Printing and Dyeing Industry（GB 4287-2012）.