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BioMed Research International
Volume 2015, Article ID 901508, 7 pages
Research Article

Comparison of Simultaneous Nitrification and Denitrification for Three Different Reactors

1Department of Civil Engineering, Faculty of Engineering, Naresuan University, Thailand
2Centre of Excellence for Innovation and Technology for Water Treatment, Naresuan University, Thailand
3Department of Industrial Engineering, Faculty of Engineering, Naresuan University, Thailand
4Center of Excellence for Environmental Health and Toxicology, Naresuan University, Thailand
5School of Materials Science and Engineering, The University of New South Wales, Australia
6International Research Centre for River Basin Environment, University of Yamanashi, Japan

Received 4 August 2014; Revised 19 October 2014; Accepted 21 October 2014

Academic Editor: J. P. A. Hettiaratchi

Copyright © 2015 W. Khanitchaidecha et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Discharge of high NH4-N containing wastewater into water bodies has become a critical and serious issue due to its negative impact on water and environmental quality. In this research, the performance of three different reactors was assessed and compared with regard to the removal of NH4-N from wastewater. The highest nitrogen removal efficiency of 98.3% was found when the entrapped sludge reactor (ESR), in which the sludge was entrapped in polyethylene glycol polymer, was used. Under intermittent aeration, nitrification and denitrification occurred simultaneously in the aerobic and anaerobic periods. Moreover, internal carbon was consumed efficiently for denitrification. On the other hand, internal carbon consumption was not found to occur in the suspended sludge reactor (SSR) and the mixed sludge reactor (MSR) and this resulted in nitrogen removal efficiencies of SSR and MSR being 64.7 and 45.1%, respectively. Nitrification and denitrification were the main nitrogen removal processes in the aerobic and anaerobic periods, respectively. However, due to the absence of sufficient organic carbon, denitrification was uncompleted resulting in high NO3-N contents in the effluent.