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.
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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.
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Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 148 • Issue 9 • September 2022
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
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