Advanced treatment of the effluent from anaerobic-aerobic biological treatment of vitamin C wastewater with electrolytic oxidation coupled with AF-MBBR integrated reactor was studied. Electrolytic oxidation was effective for decolorization, and the optimal operation conditions were as following: pH of 4, current density of 50 mA/cm2, electrolysis time of 15 min, and the distance of electrodes of 25 mm. Under these conditions, the TOC and chroma of effluents were 97.6~123.2mg/L and 135-155 times respectively. The ratio of BOD5/COD increased from less than 0.1 to about 0.24. Upon pretreatment, the effluent was further treated through AF-MBBR integrated reactor. The TOC, chroma and NH4+-N decreased to 57.18mg/L, 60 times and 2.55mg/L respectively, which primarily discharge met the standards (GB 21903-2008) for fermentation pharmaceutical industry, verifying the feasibility of the combined treatment process for advanced treatment of vitamin C wastewater. The optimum HRT of the integrated reactor was 10h. The addition of 100 mg/L glucose substantially enhanced denitrification and more than 78.1% of TN was removed. It showed that glucose could be used as the appropriate carbon resource for denitrification for advanced treatment of vitamin C wastewater. In addition, ultraviolet and infrared analysis showed that the chromophore was mainly from the carbonyl groups, which could be broken by the electrolytic oxidation and the AF-MBBR biological treatment.%采用电解氧化和厌氧生物滤池-好氧移动床生物膜(AF-MBBR)一体化反应器组合工艺对维生素C生产企业的二级生化出水进行深度处理.结果表明,电解氧化预处理具有较好的脱色效果,优化的运行条件为:pH值为4、电流密度50mA/cm2、极板间距25mm、电解时间15min.此时出水TOC降为97.6～ 123.2mg/L、色度降为135～155倍、BOD√COD从不足0.1提高到0.24左右.出水进入AF-MBBR一体化反应器处理,出水平均TOC、色度和氨氮可分别降至57.18mg/L、60倍和2.55mg/L,基本达到发酵制药行业排放标准(GB 21903-2008),表明该工艺用于维生素C废水的深度降碳脱色处理具备可行性.一体化反应器的最佳HRT为10h.当进水中添加100mg/L的葡萄糖后,反应器脱氮效果得到较大改善,TN平均去除率可达78.1％,这表明葡萄糖适宜作为维C废水深度处理时的反硝化碳源.紫外及红外光谱分析结果表明主要发色基团为羰基,电解氧化和生化处理均能破坏其双键结构,从而获得较好脱色效果.
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