Passive and Active Methods for Enhancing Water Quality of Service Reservoir
Publication: Journal of Hydraulic Engineering
Volume 139, Issue 7
Abstract
Knowledge of flow pattern and water age distributions in service reservoirs is of the utmost importance for ensuring water quality supplied to the customers. In this article, a balancing reservoir was first investigated as a benchmark case. Using the computational fluid dynamics (CFD) method coupled with dynamic meshes, the flow pattern and water age distributions in the reservoir were simulated under actual service conditions. The calculated flow pattern indicated the migration and evolution of flow recirculation regions in the reservoir, which would lead to nonuniform lateral and vertical distributions of the water age, and therefore residual chlorine concentration. A passive flow control method, by adjusting the original circular nozzles to elliptical nozzles, was explored to enhance the water quality. It was found that using elliptical nozzles could assist fluid mixing in the reservoir. The water in the modified reservoir with elliptical nozzles had 5% lower age values than those of the original. Next, bubble plumes were used as an active method to enhance the water quality in the balancing reservoir. It was found that bubble plumes could enhance the fluid mixing significantly in both the vertical and lateral directions. Consequently, the modified reservoir with bubble plumes had 10% lower age values than those of the original reservoir. Therefore, the use of bubble plumes is suggested to be a viable approach for enhancing the water quality in a balancing reservoir, which is deemed to be novel in this field.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors extend appreciation to the Public Utilities Board of Singapore for the support of this research. Special thanks are given to Mr. Gek Hee Tan, Ms. Joyce Lau, Mr. Khee Lin Yeo, Miss Xingxia Chen, and Mr. Kim Hoo Lee for sharing their knowledge and expertise. The support of SingHealth Foundation Research Grant (#SHF/FG503P/2012) is gratefully acknowledged.
References
Agranovski, I. E., Myojo, T., and Braddock, R. D. (1998). “Bubble filtering through porous media.” J. Aerosol. Sci., 29(Supplement 2), 1075–1076.
Agranovski, I. E., Myojo, T., and Braddock, R. D. (1999). “Removal of aerosols by bubbling through porous media.” Aerosol. Sci. Technol., 31(4), 249–257.
Agranovski, I. E., Myojo, T., and Braddock, R. D. (2001). “Comparative study of the performance of nine filters utilized in filtration of aerosols by bubbling.” Aerosol. Sci. Technol., 35(4), 852–859.
Ali, B. A., Kumar, C. S., and Pushpavanam, S. (2008). “Analysis of liquid circulation in a rectangular tank with a gas source at a corner.” Chem. Eng. J., 144(3), 442–452.
Ali, B. A., and Pushpavanam, S. (2011). “Analysis of unsteady gas-liquid flows in a rectangular tank: comparison of Euler-Eulerian and Euler-Lagrangian simulations.” Int. J. Multiphase Flow, 37(3), 268–277.
Bernard, R. S., Maier, R. S., and Falvery, H. T. (2000). “A simple computational model for bubble plumes.” Appl. Math. Modell., 24(3), 215–233.
Boegman, L., and Sleep, S. (2012). “Feasibility of bubble plume destratification of central Lake Erie.” J. Hydraul. Eng., 138(11), 985–989.
Bravo, H. R., Gulliver, J. S., and Hondzo, M. (2007). “Development of a commercial code-based two-fluid model for bubble plumes.” Environ. Modell. Softw., 22(4), 536–547.
Clift, R., Grace, J. R., and Wuber, E. M. (1978). Bubbles, drops and particles, Academic, San Diego.
Debroy, T., Majumdar, A. K., and Spalding, D. B. (1978). “Numerical prediction of recirculation flows with free convection encountered in gas-agitated reactors.” Appl. Math. Modell., 2(3), 146–150.
Deleersnijder, E., Campin, J. M., and Delhez, E. J. M. (2001). “The concept of age in marine modeling I. Theory and preliminary model results.” J. Mar. Syst., 28(3–4), 229–267.
Grayman, W. M., Rossman, L. A., Deininger, R. A., Smith, C. D., Arnold, C. N., and Smith, J. F. (2004). “Mixing and aging of water in distribution system storage facilities.” J. Am. Water Works Assoc., 96(9), 70–80.
Gutmark, E. J., and Grinstein, F. F. (1999). “Flow control with noncircular jets.” Annu. Rev. Fluid Mech., 31(1), 239–272.
Mahmood, F., Pimblett, J. G., Grace, N. O., and Grayman, W. M. (2005). “Evaluation of water mixing characteristics in distribution system storage tanks.” J. Am. Water Works Assoc., 97(3), 74–88.
Martinelli, L., Talvy, S., Liégeois, S., Berghe, A. V., Chauveheid, E., and Haut, B. (2011). “Single-phase flow model development for macroscopic liquid flow evaluation in gas-liquid reactors, by computational fluid dynamics.” Chem. Eng. Sci., 66(14), 3369–3376.
Menter, F. R. (1994). “Two-equation eddy-viscosity turbulence models for engineering applications.” AIAA J., 32(8), 1598–1605.
Neto, I. E. L., Zhu, D. Z., and Rajaratnam, N. (2008). “Effect of tank size and geometry on the flow induced by circular bubble plumes and water jets.” J. Hydraul. Eng., 134(6), 833–842.
Rossman, L. A., and Grayman, W. M. (1999). “Scale-model studies of mixing in drinking water storage tanks.” J. Environ. Eng., 125(8), 755–761.
Stantec. (2012). “Mitigating the impacts of elevated water storage tanks on water quality.” IDS-water -white paper, 〈http://www.idswater.com/water/us/water_storage_tanks/194/paper_login.html〉 (Feb. 30, 2012).
Tian, X., and Roberts, P. J. W. (2008). “Mixing in water storage tanks. I. No buoyancy effects.” J. Environ. Eng., 134(12), 974–985.
Walt, E. V. D. (2002). “Modeling of chlorine losses in potable water reservoirs.” Biennial Conf. of the Water Institute of Southern Africa (WISA), Water Institute of Southern Africa, Midrand, South Africa.
Yeung, H. (2001). “Modelling of service reservoirs.” J. Hydroinf., 3, 165–172.
Zhang, J. M., Khoo, B. C., Lee, H. P., Teo, C. P., Haja, N., and Peng, K. Q. (2012). “Effects of baffle configurations on the performance of a potable water service reservoir.” J. Environ. Eng., 138(5), 578–589.
Zhang, J. M., Lee, H. P., Khoo, B. C., Teo, C. P., Haja, N., and Peng, K. Q. (2011). “Modeling and simulations of flow pattern, chlorine concentration and mean age distributions in a potable water service reservoir of Singapore.” J. Environ. Eng., 137(7), 575–584.
Information & Authors
Information
Published In
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jun 13, 2012
Accepted: Dec 20, 2012
Published online: Dec 22, 2012
Published in print: Jul 1, 2013
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.