Abstract
The chemical oxygen demand (COD) and NH3-N in the coke-plant wastewater were treated by an immobilized-microbial-cell anaerobic-aerobic system. Compared with activated sludge system and immobilized nitrifiers system, the immobilized-microbial-cell anaerobic-aerobic system was more promising. When the inlet content of COD and NH3-N in the wastewater was about 1,350 mg/l and 287 mg/l, the removal efficiency of COD and NH3-N can yield up to 90.2% and 91.6%, respectively, after it was treated by the immobilized-microbial-cell anaerobic-aerobic system for 48 h. The pollutant concentration of COD and NH3-N would meet the required discharge state standard GB8978-1996 in China. Results showed that the immobilized-microbial-cell anaerobic-aerobic system had better effluent quality than the activated sludge system and immobilized nitrifiers system in terms of the simultaneous removal of COD and NH3-N in the coke-plant wastewater.
Acknowledgments
The authors are grateful for financial support from MOE projects IRT 0517, NCET-05-0267, and NCET-06-261, Shanxi Returned Scholarship (2005-21, 2006-29) and Natural Science Fund of Shanxi (20051017). They also wish to thank Professor Weiren Bao for valuable suggestions and Prof. Chunsheng Xuan for assistance with the analysis equipment.