Performance and Analysis of Tracer Tests to Determine Compliance of a Disinfection Scheme With the SWTR

Teefy, Susan; Singer, Philip C.

doi:10.1002/j.1551-8833.1990.tb07073.x

Cited by 33 publications

(11 citation statements)

References 2 publications

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“…It characterizes the probability distribution function of the residence time (Θ) of a fluid element in the total tank (Stamou, 2008). The RTD functions of the individual tanks in the TIS model are statistically independent of one another because of a perfect mixing that exists at any boundary between two tanks (Teefy & Singer, 1990).…”

Section: Background Design Conceptsmentioning

confidence: 99%

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Assessment of hydraulic flocculation processes using CFD

Vadasarukkai¹,

Gagnon²,

Campbell³

et al. 2011

Journal AWWA

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The performance of flocculation tanks either in full‐ or pilot‐scale systems cannot be fully quantified using average velocity gradient values (G values) alone. The computational fluid dynamics (CFD) process was used to investigate the turbulent flow characteristics of a three‐stage hydraulic flocculation facility at the J.D. Kline Water Supply Plant in Halifax, Nova Scotia. Calculations of the local velocity gradient were achieved using predicted energy dissipation rates. CFD analysis showed unbalanced mixing conditions in the hydraulic flocculation tanks resulting from short‐circuiting and from recirculation zones. Inconsistent mixing energy, interrupted with severe spikes in the localized G values at the weir columns, led to little or no mixing energy in most of the regions in the flocculation tanks. Practical outcomes of operating at such varying mixing gradients can be detrimental to the flocculation process and overall organic removal in the treatment plant.

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Section: Background Design Conceptsmentioning

confidence: 99%

“…These two important parameters, t m and

σ_{Θ}^{2}

, are used to characterize RTD curves (Teefy & Singer, 1990). Comparison of the calculated t m with the theoretical mean (HRT

{\overset{t}{true}}_{N}

) yields an insight into the importance of preferential flow paths and stagnation zones in the tank (Kennedy et al, 2006).…”

Section: Background Design Conceptsmentioning

confidence: 99%

Assessment of hydraulic flocculation processes using CFD

Vadasarukkai¹,

Gagnon²,

Campbell³

et al. 2011

Journal AWWA

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show abstract

“…ter adding 50,000 virtual PAC particles to the influent. After finishing the simulation, the velocity in the hBPC was calculated and PAC particle breakthrough curves were made to calculate the mean retention time (Teefy and Singer, 1990). The PAC particles were assumed to be spherical and approximately the same density as the PAC.…”

Section: Application Of Cfd Simulations To Variations Of Hbpc Configumentioning

confidence: 99%

Application of Computational Fluid Dynamics for Optimal Design of Horizontal-Flow Baffled-Channel Powdered Activated Carbon Contactors

Kim¹,

Ahn

Lee

et al. 2009

Environmental Engineering Science

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For more efficient design of a horizontal-flow baffled-channel powdered activated carbon (PAC) contactor (hBPC), which might be used to cope with taste and odor problems at conventional water treatment plants, computational fluid dynamics (CFD) using FLOW-3D was applied. In order to verify the performance of the CFD simulations, the experimental results of tracer tests from a pilot-scale hBPC were compared to those from the simulation. Results from the CFD simulation were very similar to those of the tracer tests. Velocity distributions showed that there were stagnant regions on the back side of the baffles. These stagnant regions would be expected to decrease the overall adsorption efficiency of the PAC particles. The size of the stagnant regions and retention times in the simulated hBPC increased as the length to width (L/W) ratio increased and the bend width decreased. The L/W ratio, bend width, and the number of baffles for optimal design of the hBPC were successfully generated by the simulation. When designing a full-scale hBPC, the designer should consider the L/W ratio, number of baffles, and bend width in order to maximize the hBPC performance.

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“…From these studies, the effective contact time (t 10 ) could be obtained and used to determine Ct 10 and the corresponding microorganism inactivation credit. This approach is considered to be a relatively accurate method of evaluation for microorganism inactivation efficiency (Regli 1989;Teefy and Singer 1990).…”

Section: Storage Tanks As Contact Chambersmentioning

confidence: 99%

Computational fluid dynamics application in modeling and improving the performance of a storage reservoir used as a contact chamber for microorganism inactivation

Baawain¹,

El-Din²,

Smith³

2006

Journal of Environmental Engineering and Science

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This study explored the use of computational fluid dynamics (CFD) modeling approach to simulate two tracer studies conducted, in scaled-down physical models of an existing storage tank, to investigate the effect of tank configuration on the effective contact time (t 10 ). One of the scaled-down physical models, of the storage tank, was equipped with one baffle wall at the middle length and the other was equipped with nine baffle walls distributed evenly along the reservoir length. A comparison between the experimental and modeled tracer concentration profiles showed an excellent agreement. The developed CFD model was then applied to different reservoir configurations for further investigation towards achieving t 10 improvement. The use of seven small inlets and nine baffle walls resulted in extending the t 10 from about 8 min to about 30 min (for a theoretical detention time, τ , of 32 min). Furthermore, using fewer baffle walls with different inlet arrangements enhanced the t 10 .Résumé : La présente étude examine l'utilisation de la modélisation de la dynamique computationnelle des fluides pour simuler deux études à l'aide d'indicateurs, effectuées dans les modèles physiques réduits d'un réservoir de stockage existant, afin d'étudier l'effet de la configuration du réservoir sur le temps de contact efficace (t 10 ). L'un des modèles physiques réduits du réservoir de stockage a été muni d'un mur déflecteur au milieu de la longueur et l'un autre a été muni de neuf murs déflecteurs distribués également sur la longueur du réservoir. Une comparaison entre les profils de concentration à l'aide d'indicateurs modélisés et les profils expérimentaux a montré une excellente corrélation. Le modèle de dynamique computationnelle des fluides développé a été appliqué à différentes configurations de réservoir comme complément d'étude afin d'améliorer le t 10 . L'utilisation de sept petits points d'entrée et de neuf murs déflecteurs a permis d'allonger le t 10 d'environ huit minutes à environ 30 minutes (pour un temps de séjour théorique, τ , de 32 minutes). De plus, l'utilisation de moins de murs déflecteurs avec différents arrangements de points d'entrée a amélioré le t 10 .

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Performance and Analysis of Tracer Tests to Determine Compliance of a Disinfection Scheme With the SWTR

Cited by 33 publications

References 2 publications

Assessment of hydraulic flocculation processes using CFD

Assessment of hydraulic flocculation processes using CFD

Application of Computational Fluid Dynamics for Optimal Design of Horizontal-Flow Baffled-Channel Powdered Activated Carbon Contactors

Computational fluid dynamics application in modeling and improving the performance of a storage reservoir used as a contact chamber for microorganism inactivation

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