Degradation Of Phenol In A Plug Flow Electrochemical Reactor With Mesh Plate Electrode

The plug flow(also known as tubular) electrochemical reactor(PFER) is a novel electrochemical treatment technology developed in recent years. It can make the energy consumption per unit of pollutant conversion rate reach a maximum value. The plug flow electrochemical reactor with mesh plate electrode(MPE-PFER) is easy to make the electrode surface form turbulence and conductive to transfer and decomposition of aqueous phase contaminants, for the wastewater flows through the electrode surface perpendicularly, and the meshed electrodes would affect the flow dynamics and enhance the turbulence intensity. Particle image velocimetry (PIV) can directly show the flow field in a reactor, understand the fluid flow information and provide the basis for the design and scale-up of reactor.in this paper, the particle image velocimetry (PIV) was used to test its overall flow field. The velocity field distribution in the inlet section and central reaction section was analyzed. Meanwhile, the influences of entrance velocity and inlet configuration on fluid field distribution and pressure drop were studied specifically. The results show that the entrance region is a transition zone and is greatly affected by the inlet design, the flow in the central region is usually stable and regular, and the velocity gradient and pressure drop increase obviously with the flow rate increasing. Relatively speaking, the design with inlet tangential to the reactor wall is the best for its well-distributed flow fields and low pressure drop.Secondly, the plug flow electrochemical reactor with mesh plate electrode was used to dispose the phenolic wastewater. The effect of pH, concentration of supporting electrolyte Na2SO4, current density, phenol original concentration, the type of reactor inlet and flow rate were studied by measuring the phenol concentration and TOC. The experiment results show that the optimum process conditions were satisfied at20g-L1external electrolyte concentration,10mA·cm-2current density,200mg·L-1(±10mg·L-1initial phenol concentration, radial and tangent inlet,0.008m·s-1and0.011m·s-1flow rate.Finally, under the above-mentioned optimized conditions, the pollutant concentration in the reactor along the axial position was analysed for radial in radial inlet and0.011m·s-1. The equation of phenol concentration in the reactor changed with time was obtained:. The phenol removing rate and export concentration also could computed on the basis of the equation. Furthermore, the phenol degradation followed the first-order kinetics model and the reaction rate constant was0.0135s-1.