Residence Time Distribution as a Tool for Hydrodynamic Study of Electrocoagulation Reactors Design and Scaling up

Abstract

An electrocoagulation reactor operating continuously is designed for the treatment of industrial effluents in Senegal. One of the main challenges for electrocoagulation reactors design is each reactor is specific for its domain. In this paper, a methodology using residence time distribution curve (RTD) is presented and can be used for any other examples. The optimization of the operating parameters such as the flow rate, the residence time, the conductivity and so on for the treatment of these effluents requires an understanding of the reactor hydrodynamics. Thus, this hydrodynamic study based on the residence time distribution curve (RTD) showed the presence of dead zone in the reactor with a theoretical residence time of 607.76 s for an average residence time obtained from the residence time distribution curve of 554.85 s. A comparison of the curve obtained experimentally with the curves for an ideal reactor of the piston type or of a perfectly stirred type, has shown that the electrocoagulation reactor behavior is like a cascade of two perfectly stirred reactors with a difference between them of 0.15%. The numerical simulation with COMSOL allowed to illustrate the velocity fields and to highlight the preferential zones during the flow in the reactor and thus to confirm the results obtained with the hydrodynamics with a relatively low absolute error of 4.6% obtained with the least squares method.