|
|
|
| Advanced treatment of vitamin C wastewater by electrolytic oxidation and AF-MBBR integrated reactor |
|
|
|
|
Abstract 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.
|
|
Received: 24 January 2011
|
|
|
|
|
|
|
