电解氧化-AF-MBBR处理维生素C生产废水

Advanced treatment of vitamin C wastewater by electrolytic oxidation and AF-MBBR integrated reactor

采用电解氧化和厌氧生物滤池一好氧移动床生物膜（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、BOD5／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（GB21903—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100mgTL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．

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 BODJCOD 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.