A simple model for flow behavior and liquid mixing in bubble columns containing Newtonian (water and salt solutions) and non-Newtonian (CMC at different concentrations) liquids was developed. Based on an energy balance which takes into account the energy losses at the gas-liquid interface, and on the Baird and Rice relation for axial dispersion, the model predicts experimental data of gas holdup, liquid velocities profiles and liquid axial dispersion coefficient with satisfactory accuracy in a wide range of column sizes, fluid systems and experimental conditions. Model predictions were compared with recommended correlations for different types of fluids and a good agreement was found. Therefore, the present model may be a more general tool for fluid dynamic and mixing description of bubble columns.