Analysis of microbial community of activated sludge in different aeration basins within petrochemical industry wastewater treatment system by PCR-DGGE

To enhance the efficiency of A/O process for petrochemical wastewater treatment, the relationship between bacterial community structure and the pollutants loading/degrading rates are analyzed by the polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) technique. The results show; in the condition of COD loading between 424.92 mg/L and 559.10 mg/L and NH₃-N between 63.60 mg/L and 100.87 mg/L, the removal rate of COD and NH₃-N is low as 69.42% and 31.2% respectively. The removal rate of COD and NH₃-N fluctuats with bacterial categories in the bioreactor. The profde of bacterial community in different units by PCR-DGGE show that the number of bacterium bands chang a lot and the highest similar coefficient is 36.11% and the lowest is 6.25%, and that the similarity of bacterial community structure is extremely low. The experimental results indicate that the relationship between structure of bacterial community and its functions may be elucidated with the analysis of such variation.