WANG Yu;GAO Qi;SHI Yunxiang;CHEN Kunjie;College of Engineering, Nanjing Agricultural University;SPH Xing Ling Sci. &Tech. Pharmaceutical Company Limited;Nanjing Dashan Environmental Technology Company Limited;

ginkgo ketone ester production wastewater;;anaerobic fermentation;;electrochemical oxidation;;COD removal rate;;BOD_5 removal rate;;decolorization rate

By use of the production wastewater of ginkgo ketone ester, we employed the single factor test to screen out the optimized process conditions. These conditions included a group of sludge mass concentration(3 000, 4 000, 5 000,6 000, 6 000, 7 000 mg/L), pH(4, 5, 6, 7, 8, 9), fermentation temperature(20, 25, 30, 35, 40, 45 ℃) and fermentation time(3, 4, 5, 6, 7, 8 d). The orthogonal test of 4 factors and 3 levels was designed based on fermentation temperature,fermentation time, pH and sludge mass concentration. The optimal process parameters for degradation of COD in wastewater by anaerobic fermentation were as follows: the fermentation temperature of 35 ℃, the fermentation time of 5 d, the pH of 7, and the sludge mass concentration of 5 000 mg/L. And the COD removal rate of wastewater reached71.62%. In this study, the influence of electrochemical oxidation pretreatment on the effect of anaerobic fermentation on the treatment of wastewater was also analyzed. After electrochemical oxidation+anaerobic fermentation treatment of ginkgo ketone ester production wastewater, the COD removal rate reached 90.62%, the decolorization rate reached96.42%, and the BOD_5 removal rate reached 86.33%. When the fermentation time was 3 d, the removal rate of COD in the wastewater tended to be stable. We concluded that electrochemical oxidation+anaerobic fermentation could obviously improve the COD removal rate and decolorization rate of ginkgo ketone ester production wastewater, and shorten the fermentation time.