BIODEGRADATION OF PYRIDINE IN SEQUENCING BATCH BIOFILM REACTOR BASED ON DISSOLVED OXYGEN CONTROL

In this study, dissolved oxygen (DO) was controlled in a sequencing batch biofilm reactor (SBBR) to construct the pyridine wastewater biodegradation system. The effects of DO concentration and pyridine loading on the system removal efficiency were investigated. Results showed that the optimal DO concentration and pyridine loading were 3.5 mg/L and 0.5 kg COD/(m(3).d), respectively. Under operating conditions, pyridine removal rate by biodegradation could reach 80.89%. GC-MS analyser was used to determine the water quality of effluent, and the main intermediate products of biodegradation were 2-pentanone, 3-pentanone, methylbutyrate and dimethylformamide. As revealed by the DGGE results, the degradation of pyridine in the SBBR system was a synergistic effect of different kinds of microorganisms, including various dominant bacteria existing in a system. The main dominant microorganisms were Shinella zoogloeoides and Acidovorax caeni, as suggested by the results of DNA sequencing of the V3 region.