Continuous flow tubular electrochemical reactor (CTER) was simulated by finite element method (FEM) for industrial and domestic wastewater treatment in this study. CTER was operated at response surface optimized conditions and the reaction kinetics was determined by the method of initial rates. Continuous flow tubular electrochemical reactor was divided into 26668 elements with minimum element quality of 0.07383, and the governing equations were solved in 28800 s for paint industry and textile industry wastewater, and in 14400 s for domestic wastewater with time step of 1 s using COMSOL Multiphysics 4.1. In the convection-diffusion-reaction model, a semi-empirical reaction rate with time-dependent weight ratios was defined for the overall COD removal in order to balance the contribution of reaction kinetics and electrochemical mass transfer due to the complex reaction mechanism of the electrochemical oxidation phenomena. This approximation gives flexible behavior in all reaction regimes with significant structures. Regression coefficients of the model simulation indicated an excellent correlation with the experimental data of electrochemical treatment of industrial and domestic wastewater. (C) 2014 The Electrochemical Society.