A new settling velocity model to describe secondary sedimentation

Ramin, Elham; Wágner, Dorottya Sarolta; Yde, Lars; Binning, Philip John; Rasmussen, Michael R.; Mikkelsen, Peter Steen; Plósz, Benedek G.

doi:10.1016/j.watres.2014.08.034

Cited by 72 publications

(56 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When concentration profile observations are available, compression parameter sensitivities greatly increase, especially in experimental layout 3, where sensitivity functions of several compression parameters can be even larger than those of hindered settling parameters. This finding shows that the solids concentration distribution in the high concentration range is profoundly influenced by the compression settling behavior, thus making the concentration profile measurements informative for compression parameter calibration, which agrees with the previous conclusion that collecting concentration profile data is recommended for hindered-compression model calibration (Kinnear, 2002;De Clercq et al, 2008;Ramin et al, 2014c).…”

Section: Parameter Selection For Identifiability Analysissupporting

confidence: 90%

“…Currently, several more advanced settling models have been developed to improve the model predictions, for example the hindered-transient-compression model developed by Ramin et al (2014c) have been demonstrated to be more effective than the state-of-the-art settling model for batch settling predication. For these advanced SST models, the increase of model complexity can be expected, such as the size of model parameters can be close 10.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, Ramin et al (2014c) found that the logarithmic compression stress function, as the state-of-the-art function, is not effective for model calibration, even if the additional concentration profile measurements are provided, which implies the need of more accurate mathematical description of the compression behavior.…”

Section: Model Structurementioning

confidence: 99%

“…It is noticeable that the hindered-compression settling models cannot be calibrated straightforwardly following these two approaches because of the inclusion of the additional compression parameters. Several proposed calibration methods require the use of advanced techniques, such as radiotracing, to measure the dynamic concentration distribution during batch settling experiments (Kinnear, 2002;De Clercq et al, 2005;De Clercq et al, 2008), which is beyond the accessibility of most practical application cases (Li and Stenstrom, 2014b;Ramin et al, 2014c). Therefore, to promote the application of the hindered-compression settling model, great efforts are needed to facilitate its calibration.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, to promote the application of the hindered-compression settling model, great efforts are needed to facilitate its calibration. For example Ramin et al (2014bRamin et al ( , 2014c reported that calibrating the hindered-compression model based on the additional measurement of the batch bottom concentration, beside the batch settling curves, has achieved some degree of success.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Practical identifiability and uncertainty analysis of the one-dimensional hindered-compression continuous settling model

Stenstrom

2016

Water Research

View full text Add to dashboard Cite

Section: Parameter Selection For Identifiability Analysissupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Model Structurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Practical identifiability and uncertainty analysis of the one-dimensional hindered-compression continuous settling model

Stenstrom

2016

Water Research

View full text Add to dashboard Cite

Electrical conductivity measurements and the nonhomogeneous settling behavior of aqueous suspensions of barite

et al. 2022

View full text Add to dashboard Cite

Using electrical conductivity measurements to monitor the local concentration of solids indirectly in settling tests is a practice already explored in the literature. However, since suspended particles may comprise a mixture of solids, a new suspension preparation methodology and calibration procedure were proposed to eliminate the influence of soluble materials on conductivity measurements. This article investigates water-barite suspensions of 10%, 15%, and 20% v/v in solids. Their settling dynamics resulted in particle Reynolds numbers and Peclet numbers always smaller than 0.0012 and larger than 2100, respectively. Particle agglomeration, multiple boundaries (layers of different maximum local concentrations), channeling (formation of flow paths or channels), and particulate stratification were some phenomena inferred from the results. Hence, this article illustrates that settling behaviors typically seen in solid-liquid mixtures of non-Newtonian continuous phase can also occur in aqueous suspensions, indicating there are still considerable challenges to understanding the process of gravitational settling.

show abstract

Turbulence and interphase mass diffusion assumptions on the performance of secondary settling tanks

Gao

Stenstrom

2019

Water Environment Research

View full text Add to dashboard Cite

Secondary settling tanks (SSTs), also known as secondary sedimentation tanks or secondary clarifiers, are a basic yet complicated process in a biological water resource recovery facility. In order to understand and improve SST performance, computational fluid dynamics methods have been employed over the last 30 years. In the present investigation, a Fluent-based two-dimensional axisymmetric numerical model is applied to understand the effects of the buoyancy term (G b ) in the turbulent kinetic energy (TKE) equation and two model parameters (the coefficient of buoyancy term (C 3 ) in the turbulent dissipation rate equation and the turbulent Schmidt number (σ c ) in the sludge transport equation) on the performance of an SST. The results show that the hydrodynamics can only be correctly predicted by buoyancy-coupled TKE equation, unless the mixed liquor suspended solids is low and sludge settling velocity is extremely high. When the field observations show the SST is operating well, the buoyancy-decoupled TKE equation predicts the correct result, but the buoyancy-decoupled TKE equation may predict failure. Care is required in selecting the correct modeling technique for various conditions. This study provides guidance on how to avoid modeling problems and increase rates of convergence. © 2018 Water Environment Federation • Practitioner points• C3 can be set to zero to improve rate of convergence and reduce computing time.• σc can be used to adjust SBH, when ESS and RAS concentrations are well calibrated to the field data, but the SBH does not fit field observation.• Key words buoyancy effects; computational fluid dynamics modeling; Realizable k-ε model; secondary settling tank; turbulent Schmidt number *WEF Member

show abstract

A new settling velocity model to describe secondary sedimentation

Cited by 72 publications

References 22 publications

Practical identifiability and uncertainty analysis of the one-dimensional hindered-compression continuous settling model

Practical identifiability and uncertainty analysis of the one-dimensional hindered-compression continuous settling model

Electrical conductivity measurements and the nonhomogeneous settling behavior of aqueous suspensions of barite

Turbulence and interphase mass diffusion assumptions on the performance of secondary settling tanks

Contact Info

Product

Resources

About