The separation of metals from aqueous streams by continuous polyrner enhanced ultrafiltration (PEUF) was modelled in order to understand, evaluate and optimise the feasibility of the process. The mathematical model developed has three sections: mass balances, equilibriurn of rnetal-polymer complexation and rules for UF membrane separation. On the one hand, the modeJ allows an examination of the influence of physico-chernical variables (affinity between the metal ion and the complexing polyrner groups) and engineering parameters (rnainly expended acid and base reagents, amount of polymer used and recyc1ing strearn flow) on the quality and productivity of the treated water stream. On the other band, a' suitable representation of the simulation results has been shown to be helpful in choosing operation pararneter values that Iead to the stable output oftreated water with the desired quality and productivity.