Study Of The Advanced Treatment On Vitamin C Wastewater

Vitamin C wastewater, as one typical wastewater of pharmaceutical fermentation industry, used only be treated by the traditional anaerobic-aerobic methods, cannot meet the standards (GB21903-2008) for fermentation pharmaceutical industry. The effluent had the characteristics of high salinity, high chroma and poor biodegradability. This paper was looking forward to seek a simple and convenient method for the advanced treatment. Firstly, electrolytic oxidation was researched as the pretreatment. Secondly, the bio-augmented integrated reactor was used for advanced treatment. Lastly, in order to obtain parameters in the actual project, the industrialized demonstration project was studied. The results showed that:(1) The effect of electrolytic oxidation was studied. Electrolytic oxidation was effective for decolorization, and the optimal operation conditions were as following: pH of4, current density of50mA/cm2, electrolysis time of15min, and the distance of electrodes of25mm. Under these conditions, the chroma of effluents decreased from almost300times to150times. The TOC of effluents were still100mg/L which could not meet the new standards yet. Nevertheless, the ratio of BOD5/COD increased from less than0.1to about0.24. Upon pretreatment, the biodegradability of the wastewater was promoted significantly which made good condition for the follow biological treatment.(2) The advanced treatment of vitamin C wastewater using bio-augmented integrated reactor was studied. Upon pretreatment, the effluent was further treated through UBF-MBBR integrated reactor. After46days, the reactor was adapt to the wastewater. The TOC, chroma NH4+-N and TN decreased to57.18mg/L,60times2.55mg/L and41.02mg/L respectively, which primarily discharge met the standards (GB21903-2008) for fermentation pharmaceutical industry, verifying the feasibility of the combined treatment process for advanced treatment of vitamin C wastewater. The volume load of reactor reached0.062kgTOC/(m3·d). The optimum HRT of the integrated reactor was16h. The addition of100mg/L glucose substantially enhanced denitrification and more than78.1%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 UBF-MBBR biological treatment.(3) The industrialized demonstration project for advanced treatment of vitamin C wastewater was studied. The devices stayed stable for196days. The max design flow of this project was3.0m3per hour. Be treated after20minutes in the electrolytic oxidation reactor, the TOC and chroma of effluents decreased from120mg/L and300times to105mg/L and150times respectively when the current and voltage was450A and20V. Upon pretreatment, the biodegradability of the wastewater was promoted significantly and the chroma was decreased also. The effluent was further treated through UBF-MBBR integrated reactor. The TOC, chroma, NH4+-N and TN decreased to51.4mg/L,60times,3.78mg/L and36.93mg/L respectively, which primarily discharge met the standards (GB21903-2008) for fermentation pharmaceutical industry. The combined treatment process was feasible for the advanced treatment of vitamin C wastewater, which realized the goal of decarbonization, decolorization and denitrification of vitamin C wasteater.