Separation of colloidal minerals from water by oscillating flows and grouping

Halfi, Eran; Brenner, Asher; Katoshevski, David

doi:10.1016/j.seppur.2018.08.054

Cited by 6 publications

(15 citation statements)

References 10 publications

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“…These results are in contrast to the very low removal observed in the jar test, wherein less than 14% of the suspended particles were removed with similar alum doses. After 30 min of oscillation/stirring, the jar test separated only 18% and 34% of the mineral colloids using 10 and 20 mg/L alum, respectively, compared to 90% and 94% separation obtained via the oscillation technique using similar doses (Halfi et al, 2019).…”

Section: Introductionmentioning

confidence: 87%

“…This technique, which enables simultaneous aggregation and sedimentation in a single reactor, was found to perform better than the traditional mixing-based technology. The present experimental and computational study is a continuation of that previous work (Halfi et al, 2019). In the current study, the flow field in the new system is solved by using 3-D computational fluid dynamics (CFD) simulations, the results of which are compared with those of dye-injection experiments.…”

Section: Introductionmentioning

confidence: 92%

“…A detailed description of the oscillator assembly can be found in Halfi et al (2019). The paddle location inside the computational jar is presented in Figure 1.…”

Section: The Oscillatormentioning

confidence: 99%

“…The jar test apparatus is composed of six beakers, each with a stirrer that is adjustable to specific stirring velocities according to the different stages. Recently, Halfi et al (2019) suggested an original technique for colloidal particle separation from water based on flow manipulation by an oscillating device. This technique, which enables simultaneous aggregation and sedimentation in a single reactor, was found to perform better than the traditional mixing-based technology.…”

Section: Introductionmentioning

confidence: 99%

“…In our previous study (Halfi et al, 2019), a new technology termed 'grouping' for simultaneous flocculation and sedimentation was presented. This technology promotes simultaneous flocculation and sedimentation in a single tank and in shorter time than in the conventional jar test configuration.…”

Section: Introductionmentioning

confidence: 99%

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Development of an oscillation-based technology for the removal of colloidal particles from water: CFD modeling and experiments

Halfi

Arad

Brenner

et al. 2020

Engineering Applications of Computational Fluid Mechanics

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Colloidal particles removal from water is a challenge in surface water treatment. Previously, we suggested an original technique for colloidal particles separation from water based on physical flow manipulation by an oscillating device. Laboratory experiments and 2D numerical simulation indicated that this technology enhances colloidal particles grouping and enables their rapid, simultaneous aggregation and sedimentation. The 2D model used in that study was unable to fully elucidate the grouping mechanism, settling pattern, or particle trajectories. Here, we extended the numerical simulation from 2D to 3D and examined the system's distinctive flow field. The flow field was solved with computational fluid dynamics (CFD) simulations in the commercial ANSYS Fluent code and validated by dye injection experiments. The sedimentation patterns could nicely be explained by the computational results. This explanation was strengthened by two-dimensional population balance model simulations, which showed that particles aggregated in two zones trailing the paddle edges. Additionally, the results indicate significantly higher TKE values and faster upward vertical velocities at the higher oscillating frequency, which explains the different sedimentation patterns and removal efficiencies generated by the different oscillation frequencies. The use of 3D numerical simulations will help to better understand and further optimize this novel technology. ARTICLE HISTORY

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Section: Introductionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 92%

“…A detailed description of the oscillator assembly can be found in Halfi et al (2019). The paddle location inside the computational jar is presented in Figure 1.…”

Section: The Oscillatormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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