A single-tube membrane-aerated biofilm reactor (MABR) was used to investigate the effect of the reaction time, reaction temperature, pH value, C/N ratio, and sludge concentration on the removal rates of the NOx--N and COD in high-strength ammonium industrial water by supplying oxygen during the batch experiment. The homogeneous mathematical model is developed to predict their transient responses using Monod kinetics with dual substrate limitation. The model incorporates mass transport by convection and diffusion in the surrounding liquid contained inside the interconnected pores and channels within the biofilm. Transport and kinetic parameters are estimated from experiments and the model successfully predicts concentration measurements in some of the sets of experiments.