Preliminary Study and Numerical Investigation of an Electrostatic Unit for the Removal of Fluoride From Thermal Water of Ethiopian Rift Valley

Abstract

This article deals with the numerical modeling of the multiphysics investigation of an electric-field-based device for the defluoridation of Ethiopian water to mitigate fluorosis while satisfying the World Health Organization quality requirement for potable water. A tubular reactor with metallic parallel plates, connected to a static voltage source, exerts an electric force on the ion in solution, attracting it to the electrodes. Meanwhile, the ion is drifted by the laminar water flow which, in turn, allows us to separate and collect the F −-rich stream from the potable one. In this system, the electrostatic problem and the mass transport are coupled according to the highly nonlinear modified Poisson-Nernst-Planck-Stokes equations system. Therefore, carefully modeling the dielectric permittivity, the ionic diffusivity, and mobility as function of fluoride concentration and temperature, the set of operating parameters to ensure the highest fluoride removal from Ethiopian thermal water is identified.

Relevance of Essential Trace Elements in Nutrition and Drinking Water for Human Health and Autoimmune Disease Risk

“…The ideal outcome would be to have a technology that allows the use of the resource, of any origin, ensuring the correct balance of the substances contained through the self-regulation of the device. This technology is under study [129], although still in the preliminary phase, but this allows us to be moderately optimistic about a solution in the near future.…”

On the Wireless Microwave Sensing of Bacterial Membrane Potential in Microfluidic-Actuated Platforms

“…In terms of electromagnetic flux, the current density associated with the membrane potential generated by bacteria is typically in the order of . This relatively high, but extraordinarily localized in space (membrane of bacteria) and time (10–100 ms), density current could generate two-way coupling phenomena between the electromagnetic signal and fluid flow as analyzed in [ 68 ]; in their work, the fluid studied is dilute in electrical charges, and consequently the electromagnetic forces are finally neglected. Similarly in this problem, the impact of the electromagnetic signal on the fluid phase, which is also electrically dilute, in addition to be activated sporadically and for a small period of time, exponentially decays as (diffusion term in Poisson-Nernst-Planck-Stokes equation in spherical coordinates [ 69 ]).…”

A Water/Ion Separation Device: Theoretical and Numerical Investigation

“…In fact, the viscosity, which increases in high-concentration solutions, dominates the concentration dependence of D for some systems. Nevertheless, PB theory has many shortcomings because it neglects ion-ion interactions and steric effects and it is proposed that the electrolyte dynamics are better described by a modified form of the PNP equations [12,23]. From a macroscopic point of view, studied under the Poisson-Boltzmann (PB) theory, it has been shown that the response of an electrolyte to an applied voltage leads to sharp ion concentration near a surface [21,22].…”

“…In fact, the viscosity, which increases in high-concentration solutions, dominates the concentration dependence of D for some systems. Nevertheless, PB theory has many shortcomings because it neglects ion-ion interactions and steric effects and it is proposed that the electrolyte dynamics are better described by a modified form of the PNP equations [12,23].…”

“…This method is approached by the Poisson-Nerst-Planck (PNP) theory, which can be less computationally demanding than MD but, on the other hand, it succeeds only at the bulk and cannot incorporate wall effects in regions near the channel walls. At the macroscale, the PNP scheme is a popular choice to explain the relation between the electrostatic problem and the mass transport [12,13].…”