Air Flow Modeling in a Prototype Sanitary Sewer System
Publication: Journal of Environmental Engineering
Volume 144, Issue 3
Abstract
Modeling air movement in sewer systems is important because of its importance in addressing sewer odor issues and pipe corrosion. In this study, a steady-state model was developed for simulating the air pressure and movement in a prototype sewer pipe network with dropshafts and a pump station. It was found that the model was able to simulate the air pressure distribution along the trunk line with reasonable assumptions and simplifications. The lateral leakage model presented in this study suggested that the air leakage at lateral connections is a function of lateral pipe properties and the number of pipes. Increasing the pipe number has limited influence on the leakage air flow. The air pressure force, wastewater drag, and the friction force by pipe wall are dominant factors affecting the air flow in sewer pipes. The operation of the pump station affects the air pressure in the system significantly as a result of the alternate partially full and full-pipe flow condition near the pump station. The dropshafts were regarded as the key contribution for downstream pressurization of the sewer headspace.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors gratefully acknowledge the financial support from the Epcor, the Natural Sciences and Engineering Research Council of Canada, and the China Scholarship Council. The authors also wish to thank Perry Fedun for his technical support, and all crew members (Yiyi Ma, Haoming Yang, Jiafang Wei, Letian Sun, Zhi Yang, Linsey Lawson, and Amy Swanson) for their assistance in the fieldwork conducted in the summer of 2016.
References
Camino, G. A., Zhu, D. Z., and Rajaratnam, N. (2015). “Flow observations in tall plunging flow dropshafts.” J. Hydraul. Eng., 06014020.
Edwini-Bonsu, S., and Steffler, P. M. (2004). “Air flow in sanitary sewer conduits due to wastewater drag: A computational fluid dynamics approach.” J. Environ. Eng. Sci., 3(5), 331–342.
Edwini-Bonsu, S., and Steffler, P. M. (2006a). “Dynamics of air flow in sewer conduit headspace.” J. Hydraul. Eng., 791–799.
Edwini-Bonsu, S., and Steffler, P. M. (2006b). “Modeling ventilation phenomenon in sanitary sewer systems: A system theoretic approach.” J. Hydraul. Eng., 778–790.
Fisher, H. B., List, E. J., Koh, R. C. Y., Imberger, J., and Brooks, N. H. (1979). Mixing in inland and coastal waters, Academic Press, San Diego.
Guo, S., Qian, Y., Zhu, D. Z., Zhang, W. M., and Edwini-Bonsu, S. (2017). “Effects of drop structures and pump station on sewer air pressure and hydrogen sulfide: Field investigation.” J. Environ. Eng., in press.
Ma, Y., Zhu, D. Z., and Rajaratnam, N. (2017). “Air entrainment in a tall plunging dropshaft.” J. Hydraul. Eng., 04016038.
Pescod, M. B., and Price, A. C. (1982). “Major factors in sewer ventilation.” J. Water Pollut. Control Fed., 54(4), 385–397.
Potter, M. C., Wiggert, D. C., and Ramadan, B. H. (2012). Mechanics of fluids, 4th Ed., Cengage Learning, Stamford, CT.
Qian, Y., Zhu, D. Z., Zhang, W. M., Rajaratnam, N., Edwini-Bonsu, S., and Steffler, P. (2017). “Air movement induced by water flow with a hydraulic jump in changing slope pipes.” J. Hydraul. Eng., 04016092.
Rajaratnam, N., Mainali, A., and Hsung, C. Y. (1997). “Observations of flow in vertical dropshafts in urban drainage systems.” J. Environ. Eng., 486–491.
Tullis, B., and Larchar, J. (2011). “Determining air demand for small- to medium-sized embankment dam low-level outlet works.” J. Irrig. Drain. Eng., 793–800.
USACE (U.S. Army Corps of Engineers). (1980). “Engineering and design: Hydraulic design of reservoir outlet works.”, Washington, DC.
USEPA (U.S. Environmental Protection Agency). (1985). “Design manual: Odor and corrosion control in sanitary sewerage systems and treatment plants.”, Washington, DC.
Wang, Y. C., Nobi, N., Nguyen, T., and Vorreiter, L. (2011). “A dynamic ventilation model for gravity sewer networks.” Water Sci. Technol., 65(1), 60–68.
Ward, M., et al. (2011a). “Characterization of natural ventilation in wastewater collection systems.” Water Environ. Res., 83(3), 265–273.
Ward, M., Hamer, G., McDonald, A., Witherspoon, J., Loh, E., and Parker, W. (2011b). “A sewer ventilation model applying conservation of momentum.” Water Sci. Technol., 64(6), 1374–1382.
Zhang, W. M., Zhu, D. Z., Rajaratnam, N., Edwini-Bonsu, S., Fiala, J., and Pels, W. (2016). “Use of air circulation pipes in deep dropshafts for reducing air induction into sanitary sewers.” J. Environ. Eng., 04015092.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 144 • Issue 3 • March 2018
Copyright
©2018 American Society of Civil Engineers.
History
Received: Jul 14, 2017
Accepted: Sep 12, 2017
Published online: Jan 10, 2018
Published in print: Mar 1, 2018
Discussion open until: Jun 10, 2018
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.