Separation of tripeptides in binary mixtures using ion-exchange membrane adsorber

•A mathematical model is proposed to analyse the dynamic adsorption processes.•Adsorption of single and binary mixtures of GGG, GHG and GTG was analysed.•The equilibrium adsorption followed the modified and the extended Langmuir isotherms.•The adsorbed molar fraction inside the membrane was calculated by the model as a function of time.•GGG can be separated from GHG with a recovery of 35% and molar fraction higher than 99%.