One- and Three-Dimensional Computational Fluid Dynamics Model Comparison of the Treatment Performance of a Full-Scale Oxidation Ditch
Publication: Journal of Environmental Engineering
Volume 148, Issue 9
Abstract
This work developed three computational fluid dynamics (CFD) models of a full-scale oxidation ditch, one three-dimensional (3D) model and two one-dimensional (1D) models, to compare their predicted wastewater treatment performance. The models incorporated biokinetics through the Activated Sludge Model 1 (ASM-1) to predict the treatment performance of the ditch based on concentrations of pollutants: readily biodegradable substrate (), soluble ammonium ammonia nitrogen (), and soluble nitrate nitrite nitrogen (). When comparing the time series of the concentration of ASM-1 pollutants averaged over the ditch for 40 days, all three models displayed similar trends with slight differences in steady-state values, except for . The steady-state value of was greater by more than 150% for the 1D model than the 3D model. This difference is attributed to spatial heterogeneities in dissolved oxygen concentration predicted by the 3D model that were not captured by the 1D model, leading the latter to underpredict the denitrification process. Specifically, the spiraling flow around the aerators that plays an important role in determining the spatial distribution of dissolved oxygen cannot be represented in the 1D model.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request: ANSYS Fluent 3D model case files, ANSYS Fluent 1D Model A case files, MATLAB code for 1D Model B, Excel files with data from the three models.
Acknowledgments
K. Pierre acknowledges the Florida Education Fund–McKnight Doctoral Fellowship, the Alfred P. Sloan Foundation, National Science Foundation Partnerships for International Research and Education (NSF PIRE) (Grant No. 1243510), and AAUW American Fellowship for financial support. The authors acknowledge the Hillsborough County Public Utilities for partially supporting this work. Jeff Cunningham, Ph.D., is acknowledged for his invaluable input during weekly group meetings.
References
Brannock, M. 2003. “Computational fluid dynamics tools for the design of mixed anoxic wastewater treatment vessels.” Doctoral dissertation, Dept. of Chemical Engineering, Univ. of Queensland.
Climent, J., L. Basiero, R. Martinez-Cuenca, J. G. Berlanga, B. Julian-Lopez, and S. Chiva. 2018. “Biological reactor retrofitting using CFD-ASM modelling.” Chem. Eng. J. 348 (Sep): 1–14. https://doi.org/10.1016/j.cej.2018.04.058.
Fan, L., N. Xu, Z. Wang, and H. Shi. 2010. “PDA experiments and CFD simulation of a lab-scale oxidation ditch with surface aerators.” Chem. Eng. Res. Des. 88 (1): 23–33. https://doi.org/10.1016/j.cherd.2009.07.013.
Henze, M., W. Gujer, T. Mino, and M. van Loosdrecht. 2000. Activated Sludge Models: ASM1, ASM2, ASM2d and ASM3.. London: IWA Publishing.
Huang, W., K. Li, G. Wang, and Y. Wang. 2013. “Computational fluid dynamics simulation of flows in an oxidation ditch driven by a new surface aerator.” Environ. Eng. Sci. 30 (11): 663–671. https://doi.org/10.1089/ees.2012.0313.
Karpinska, A., and J. Bridgeman. 2016. “CFD-aided modelling of activated sludge systems—A critical review.” Water Res. 88 (Jan): 861–879. https://doi.org/10.1016/j.watres.2015.11.008.
Lei, L., and J. Ni. 2014. “Three-dimensional three-phase model for simulation of hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification in an oxidation ditch.” Water Res. 53 (Apr): 200–214. https://doi.org/10.1016/j.watres.2014.01.021.
Le Moullec, Y., C. Gentric, O. Potier, and J. P. Leclerc. 2010. “CFD simulation of the hydrodynamics and reactions in an activated sludge channel reactor of wastewater treatment.” Chem. Eng. Sci. 65 (1): 492–498. https://doi.org/10.1016/j.ces.2009.03.021.
Le Moullec, Y., O. Potier, C. Gentric, and J. P. Leclerc. 2008. “Flow field and residence time distribution simulation of a cross-flow gas–liquid wastewater treatment reactor using CFD.” Chem. Eng. Sci. 63 (9): 2436–2449. https://doi.org/10.1016/j.ces.2008.01.029.
Mihelcic, J. R., and J. B. Zimmerman. 2014. Environmental engineering: Fundamentals, sustainability, design. 2nd ed. Hoboken, NJ: Wiley.
Pope, S. 2000. Turbulent flows. Cambridge, UK: Cambridge University Press.
Rehman, U. 2016. “Next generation bioreactor models for wastewater treatment systems by means of detailed combined modelling of mixing and biokinetics.” Doctoral dissertation, Dept. of Mathematical Modeling, Statistics and Bio-informatics, Ghent Univ.
Socolofsky, S. A., and G. H. Jirka. 2005. “Mixing in rivers: Turbulent diffusion and dispersion.” Accessed December 21, 2021. https://publikationen.bibliothek.kit.edu/1542004/1362.
Stamou, A. I. 1997. “Modelling of oxidation ditches using an open channel flow 1-D advection-dispersion equation and ASM-1 process description.” Water Sci. Technol. 36 (5): 269–276. https://doi.org/10.2166/wst.1997.0214.
Tchobanoglous, G., F. Burton, and H. Stensel. 2003. Wastewater engineering: Treatment and reuse. Boston: McGraw-Hill.
Tominaga, Y., and T. Stathopoulos. 2007. “Turbulent Schmidt numbers for CFD analysis with various types of flowfield.” Atmos. Environ. 41 (37): 8091–8099. https://doi.org/10.1016/j.atmosenv.2007.06.054.
Wilcox, D. C. 1994. Turbulence modeling for CFD. La Cañada Flintridge, CA: DCW Industries.
Xie, H., J. Yang, Y. Hu, H. Zhang, Y. Yang, K. Zhang, X. Zhu, Y. Li, and C. Yang. 2014. “Simulation of flow field and sludge settling in a full-scale oxidation ditch by using a two-phase flow CFD model.” Chem. Eng. Sci. 109 (Apr): 296–305. https://doi.org/10.1016/j.ces.2014.02.002.
Yang, Y., J. Yang, J. Zuo, Y. Li, S. He, X. Yang, and K. Zhang. 2011. “Study on two operating conditions of a full-scale oxidation ditch for optimization of energy consumption and effluent quality by using CFD model.” Water Res. 45 (11): 3439–3452. https://doi.org/10.1016/j.watres.2011.04.007.
Zhang, J., K. C. Pierre, and A. E. Tejada-Martínez. 2019. “Impacts of flow and tracer release unsteadiness on tracer analysis of water and wastewater treatment facilities.” J. Hydraul. Eng. 145 (4): 04019004. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001569.
Information & Authors
Information
Published In
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Jul 21, 2021
Accepted: Mar 8, 2022
Published online: Jun 24, 2022
Published in print: Sep 1, 2022
Discussion open until: Nov 24, 2022
ASCE Technical Topics:
- Chemical processes
- Chemistry
- Computational fluid dynamics technique
- Computer models
- Dissolved oxygen
- Dynamic models
- Engineering fundamentals
- Environmental engineering
- Fluid dynamics
- Fluid mechanics
- Hydrologic engineering
- Models (by type)
- Oxidation
- Pollutants
- Scale models
- Three-dimensional models
- Water and water resources
- Water quality
- Water treatment
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.