Separation by Electrosorption of Organic Compounds in a Flow‐Through Porous Electrode: I . Mathematical Model for One‐Dimensional Geometry

Abstract

An engineering model of potential-dependent adsorption of organic compounds in a flow-through porous electrode was derived from fundamental principles. A one-dimensional geometry was considered in which the counterelectrode was located downstream. Potential was controlled at the end of the porous electrode nearest the counterelectrode. The model considered convective mass transfer, ohmic resistance, charging of the electrical double layer, and a potential-dependent adsorption isotherm. Electrosorption can be an efficient cyclic separation process if the full change in adsorption capacity of the adsorbent is utilized in minimum cycle time. For one-dimensional geometry, the model predicted conditions under which efficient operation could be achieved.

Electrosorption of copper ions by poly(m-phenylenediamine)/reduced graphene oxide synthesized via a one-step in situ redox strategy

“…Electrosorption is an important technology for the removal of heavy metal ions from wastewater [1][2][3], during which an electric field is applied on solid adsorbents to enhance their adsorption capacity and facilitate their subsequent regeneration by electrodesorption [4]. Carbon-based materials, such as activated carbon [1], carbon aerogels [5], carbon nanotubes [6] and carbon nanotube-graphene hybrid [7], have been adopted as electrodes for electrosorption of heavy metals.…”

Removal of chromium from tannery wastewater by electrosorption on carbon prepared from peach stones: effect of applied potential

“…1. The electrosorption cells (E) were inspired by the model of Alkire and Eisinger [12]. Each cell is made of two concentric tubes, between which circulates water with temperature measured via thermostat (T).…”

“…The latter is a very expensive operation because of the energy consumption. The approaches of some authors (Strohl and Dunlap [11] or Alkire and Eisinger [12]) utilize a completely different method of regeneration by providing electrochemical potential in situ electrochemically. Indeed, the good electrical conductivity of the charcoal and its high overvoltage in the electrolysis reactions of water, allows the possibility to use it as an electrode in solid aqueous phase.…”

Separation Processes Based on Electrosorption Phenomena

“…These calculations have been applied to experiments of Eisinger and Alkire (4) and are compared in Figure 6 with the results of these authors. Liquid phase concentration c Figure 5: Changes of equilibrium state of the bed due to changes of potential Figure 6-a represents the effluent concentration for a positive potential step causing adsorption of solute and propagation of a shock wave.…”