| The three-dimensional electrocatalytic oxidation reactor is filled with particle electrodes with high conductivity,which improves the mass transfer and electron transfer of the electrocatalytic reaction system and enhances the efficiency of the electrocatalytic reaction.In recent years,three-dimensional electrocatalytic technology has been widely recognized in the degradation of industrial wastewater,but the research on particle electrode to improve the efficiency of electrocatalytic reaction has been confined to the analysis of particle material improvement and fluid flow uniformity mass transfer Angle.Due to the lack of theoretical support on the mechanism of particle electrode electrocatalytic reaction,Therefore,it is a challenge to simulate the electrocatalytic oxidation process of particle electrode by numerical simulation method.In this paper,the electrochemical analysis module in COMSOL Multiphysics software was used to simulate the potential distribution in the particle electrode electrocatalytic reactor,and control the changes of the electric field intensity,particle size and electrode spacing of the single particle graphite particle electrode.On the basis of determining the reaction to meet the first-order reaction kinetics,A multivariate logarithmic regression model for the kinetic constants of the reaction was established.The results of potential distribution were combined with the logarithmic regression model of reaction kinetics constants to predict the efficiency of electrocatalytic reaction at different locations,and a three-dimensional efficiency distribution model of electrocatalytic reaction was established.After experimental verification,the electric field intensity,particle size and electrode spacing were changed.The results show that the particle electrode has strong electrocatalytic performance near the anode,while the electrocatalytic reaction decreases when the particle electrode is far away from the anode.The efficiency of the electrocatalytic reaction of pollutant degradation in the particle electrode electrocatalytic reactor is unevenly distributed,and the degree of ununiformity increases with the increase of electric field intensity.Reducing the particle size of the electrode can increase the specific surface area of the same reactor volume.The points with high particle electric and electrocatalytic efficiency of spherical particles are mainly concentrated in the central region of the spherical particle,and the length of the region with high electrocatalytic efficiency of spherical particles accounts for about 40% of the particle size of the spherical particle electrode.The water inlet mode,the location of the water inlet and the size of the water inlet pipe of the continuous flow THREE-DIMENSIONAL electrocatalytic oxidation reactor were optimized by using the interface of "laminar flow" and "porous media reaction flow" in COMSOL Multiphysics software.The experimental results show that the tangential inlet water in the continuous flow THREE-DIMENSIONAL electrocatalytic reactor can reduce more dead zone space and improve the uniformity of fluid flow.The inlet pipe is set at the anode plate of the particle electrode electrocatalytic reactor,which can improve the electrocatalytic reaction efficiency of particles.The inlet pipe diameter should be moderate when the inlet pipe is at the anode and should be increased when the inlet pipe is in the middle and near the cathode.The "secondary current distribution module" in COMSOL Multiphysics software was used to simulate the potential distribution of the two electrode types,and the "optimization" interface was used to simulate the optimal distribution of particle electrode stacking mode.The results showed that the amount of hydroxyl radical reached the maximum when the particle size and electrode spacing were30 mm.Three-dimensional electrocatalytic reactor with one cathode and two anodes has better electrocatalytic effect.When the particle electrode is tilted towards the water inlet,the electrocatalytic efficiency of the particle electrode can be improved. |
