Pilot Study On Distillery Wastewater Treatment By Two-Stage Anaerobic-Aerobic-Immobilized Nitrobacteria Process

The wastewater from Jiujiang Distillery Co. Ltd, Guangdong Province was treated by a hybrid system with EGSB-EGSB-Aerobic inner-circulated contact oxidation-Aerobic Fluidized bed packed with PEG-encapsulated nitrobacteria. PEG-immobilized nitrobacteria were applied to treat practical industrial wastewater for the first time in China. Through over 8 months'pilot-scale experimental research on each stage bioreactors, COD, ammonia-nitrogen, nitrite-nitrogen and nitrate-nitrogen removal rate were investigated in the pilot study. Main factors that affect the removal rate were also analyzed. Nitrification performance of immobilized nitrobacteria and the overall performance of the hybrid system were discussed in detail. The whole research can be divided into two phases: the first stage started from September 2005 to Februray 2006, and the temperature ranged from 15 oC to 25 oC; the second stage started from July 2006 to September 2006, and the temperature ranged from 25 to 35 oC.The main results of the research were listed as follows:(1) The main function of the first stage EGSB was to remove organic matters through methanogenesis and to convert KN to NH4-N. The maximum COD volume loading rate attained 10 KgCOD/m3/d, and COD removal rate under this condition is about 60-70%. The second phase experiment was conducted in summer. The maximum COD volume loading rate was 15 KgCOD/m3/d, and COD removal rate under this condition is about 60-70%. Temperature was a key factor that affected the COD removal rate of the EGSB significantly.(2) The second stage EGSB aimed to remove organic matters and NOx from the feed. In the first phase of the experiment, COD removal rate could attain 60-80% before the recycle of the effluent of nitrification tank. However, COD removal...