A comparison between the hollow fibre supported gas membrane (SGM) process and the hollow fibre supported liquid membrane (SLM) process for the separation of NH3 from aqueous solutions containing NH3 and CO2 was performed. The experimental data as well as the model simulation demonstrate that the SLM process can remove NH3 from aqueous solutions of NH3 and CO2 at a higher rate than the SGM process when the NH3 loading is low or the ratio of NH3 to CO2 is low. This study suggests that the proper combination of the SGM process and the SLM process can strip NH3 more effectively from aqueous solutions containing NH3 and CO2.