In this work, simultaneous removal of urea, ammonia, and carbon dioxide from industrial wastewater was Studied via modeling and simulation of a hydrolyzer-separator loop. The extended electrolytic UNIQUAC equation has been used to describe the nonideality of the liquid phase and the perturbed-hard-sphere (PHS) equation of state has been applied to predict the vapor fugacity coefficients. This work also uses a multistage well-mixed model for the liquid and vapor flows with a nonideal rate-based model for urea thermal hydrolyzer. Our study incorporates the reaction rate of urea hydrolysis and takes into account the effects of solution nonideality and backmixing on the reactor performance. The rates of urea reaction are written in terms of activity of reactants. The model provides temperature and flow rate distributions of different components along the height of the hydrolysis reactor and the desorbers. The simulation results have been found to be in good agreement with the plant data indicating the validity of the model. The impact of different parameters on the performance of the wastewater treatment loop has been examined. The results of this work showed that an increase in the inlet temperature of the wastewater and steam flow rate and also decrease the reflux ratio would improve the urea and ammonia removal efficiency.