Evaluation of the Hydrodynamic Performance of an Electrochemical Reactor with Rotating Ring Electrodes using CFD Analysis

摘要

Chemical precipitation, ion exchange, evaporation and reverse osmosis processes havernbeen applied to remove hexavalent chromium Cr(VI) from industrial wastewaters.rnHowever, some of chemical precipitation methods use great quantities of chemical andrnflocculating that produce elevated quantities of sludge that must be treated, handled andrndisposed, increasing the process costs. The other methods require high capital andrnoperating costs. The electrochemical process is an alternative method to remove Cr(VI)rnfrom industrial wastewaters process. However, in electrochemical plug flow reactorsrnwith no liquid mixing or static electrodes, iron salt film is formed on the electrodesrnsurface (electrode passivation) because of the poor diffusion and mass transfer thatrnreduces the Cr (VI) removal efficiency and causes greater energy consumption.rnTherefore, the electrochemical reactors require to be designed to provide high massrntransfer between the bulk liquid and the electrodes. However, their performancerngenerally has been evaluated as if they were a “black box”. In this work, thernperformance of an electrochemical reactor with rotating ring electrodes was evaluatedrnusing state-of the-art computational fluid dynamics (CFD) tools at different rotationalrnspeeds to evaluate their effect on the electrochemical process to remove Cr(VI) fromrnwastewater.