Optimization of Internal Bypass Ratio for Complete Ammonium and Phosphate Removal in a Dephanox-Type Two-Sludge Denitrification System
Publication: Journal of Environmental Engineering
Volume 134, Issue 7
Abstract
The capacity of complete simultaneous ammonium and phosphate removal was studied in a laboratory scale Dephanox system in relation to its internal bypass ratio (BPR). In this configuration, most of the ammonium detected in the effluent is ammonium bypassed by the system’s internal settler. Therefore, this research studies the possibility of complete simultaneous ammonium and phosphate removal by means of the balance of bypassed ammonium with ammonium requirement for growth of denitrifying phosphorus accumulating organisms in the anoxic tank. During these experiments, ammonium removal was governed by internal BPR and limited by sludge settleability. The predominant anaerobic-anoxic sludge developed a high settleability, allowing the application of drastic low BPRs. The system studied under many BPRs proved to achieve almost complete simultaneous ammonium and phosphate removal for BPRs ranging from 0.08 to 0.13 of the influent. A BPR lower than the inferior limit produced extreme accumulation of sludge into the internal settler, interfering in the distribution of sludge and consequently in removal efficiency. A positive effect of the internal settler was the extension of anaerobic contact time and anaerobic solids retention time. The increased phosphorus release suggests that a higher volatile fatty acids production might have occurred when raw wastewater was used as influent.
Get full access to this article
View all available purchase options and get full access to this article.
References
American Public Health Association (APHA), American Water Works Association (AWWA), and Water Environment Federation (WEF). (1995). Standard methods for the examination of water and wastewater, 19th Ed., Washington, D.C.
Barker, P. S., and Dold, P. L. (1996). “Denitrification behavior in biological excess phosphorus removal activated sludge systems.” Water Res., 30, 769–780.
Bortone, G., Malaspina, F., Stante, L., and Tilche, A. (1994). “Biological nitrogen and phosphorus removal in an anaerobic/anoxic sequencing batch reactor with separated biofilm nitrification.” Water Sci. Technol., 30, 303–313.
Bortone, G., Saltarelli, R., Alonso, V., Sorm, R., and Tilche, A. (1996). “Biological anoxic phosphorus removal—The dephanox process.” Water Sci. Technol., 34, 119–128.
Brinch, P. P., Rindel, K., and Kalb, K. (1994). “Upgrading to nutrient removal by means of internal carbon from sludge hydrolysis.” Water Sci. Technol., 29(12), 31–40.
Hao, X., van Loosdrecht, M. C. M., Meijer, S., Heijnen, J., and Qian, Y. (2001). “Model based evaluation of denitrifying P removal in a two-sludge system.” J. Environ. Eng., 127(2), 112–118.
Kerrn-Jespersen, J. P., Hence, M., and Strube, R. (1994). “Biological phosphorus release and uptake under alternating anaerobic and anoxic conditions in a fixed-film reactor.” Water Res., 28, 1253–1255.
Kuba, T., Smolders, G., van Loodrecht, M. C. M., and Heijnen, J. J. (1993). “Biological phosphorus removal from wastewater by anaerobic-anoxic sequencing batch reactor.” Water Sci. Technol., 27, 241–252.
Kuba, T., van Loosdrecht, M. C. M., and Heijnen, J. J. (1996). “Phosphorus and nitrogen removal with minimal COD requirement by integration of denitrifying dephospahtation and nitrification in a two-sludge system.” Water Res., 30(7), 1702–1710.
Kuba, T., van Loodrecht, M. C. M., and Heijnen, J. J. (1997). “Biological dephosphatation by activated sludge under denitrifying conditions: pH influence and occurrence of denitrifying dephosphatation in a full-scale waste water treatment plant.” Water Sci. Technol., 36(12), 75–82.
Kuba, T., Wachtmeister, A., van Loosdrecht, M. C. M., and Heijnen, J. J. (1994). “Effect of nitrate on phosphorus release in biological phosphorus removal systems.” Water Sci. Technol., 30, 263–269.
Matsuo, Y. (1994). “Effect of the anaerobic solids retention time on enhanced biological phosphate removal.” Water Sci. Technol., 30(6), 193–202.
Metcalf and Eddy Inc. (2003). Wastewater engineering: Treatment and reuse, McGraw-Hill, Boston.
Shoji, T., Sato, H., and Mino, T. (2001). “Use of denitrifying polyphosphate accumulating organisms for simultaneous nitrogen and phosphate removal.” Asian Waterqual, Proc., Asia-Pacific Regional Conf., IWA, 813–818.
Torrico, V., Kuba, T., and Kusuda, T. (2006). “Effect of particulate biodegradable COD in a post-denitrification enhanced biological phosphorus removal system.” J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng., 46(8), 1715–1728.
Wachtmeismer, A., Kuba, T., van Loosdrecht, M. C., and Heijnen, J. J. (1997). “A sludge characterization assay for aerobic and denitrifying phosphorus removing sludge.” Water Res., 31(3), 471–478.
Wanner, J., Cech, J. S., and Kos, M. (1992). “New process design for biological nutrient removal.” Water Sci. Technol., 25, 445–448.
Information & Authors
Information
Published In
Copyright
© 2008 ASCE.
History
Received: Apr 24, 2006
Accepted: Jul 13, 2007
Published online: Jul 1, 2008
Published in print: Jul 2008
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.