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

Abstract

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

Evaluation on Coupling of Wall Boiling and Population Balance Models for Vertical Gas-Liquid Subcooled Boiling Flow of First Loop of Nuclear Power Plant

“…It can capture the interphase behaviors with an acceptable computation amount. Recently, the PBM attracted much attention as it can calculate the bubble condensation [7,10,14], coalescence, and breakup [15,16] with various kernels or empirical relations.…”

The Role of Micro Vortex in the Environmental and Biological Processes

“…Biofouling/biofilms Turbulent Experimental/CFD [25][26][27][28][29][30] Water disinfection/irrigation Turbulent Experimental/CFD [31][32][33][34][35] Water self-purification Turbulent Experimental [43][44][45][46] Solid-liquid separation Turbulent Experimental [2,[36][37][38] Food and paper processing Turbulent Experimental [39][40][41][42] Table 2.…”

“…Further, the disintegration performance increased with the rotational speed and was minimized at the highest inlet pressure. Several other studies leveraging on the hydrodynamics of the process reactor for fluid-particle separation are available in literature [42,43]. Many of these lab-scale studies have demonstrated the feasibility of turbulence-induced fluid-particle separation.…”

“…This technique, whose implementation can result in reductions of the reactor sizes and process times, has a strong potential to improve conventional separation processes. It has also been observed that higher oscillating frequency promotes faster upward vertical velocities, resulting in different sedimentation patterns and removal efficiencies generated by the different oscillation frequencies [43]. The Role of Micro Vortex in the Environmental and Biological Processes DOI: http://dx.doi.org/10.5772/intechopen.93531 5.5.3 Swirling flow vortex pattern (e.g., stirred tank, hydrocyclone)…”

Pairwise interaction of spherical particles aligned in high-frequency oscillatory flow

“…In industrial applications, oscillating flows are used to improve agglomeration and removal of particles in water treatment facilities (Halfi, Brenner & Katoshevski 2019; Halfi et al. 2020) and in diesel engines (Katoshevski, Dodin & Ziskind 2005; Ruzal-Mendelevich, Katoshevski & Sher 2016; Gupta et al. 2019).…”