The objective of this work is to identify and select optimally the main ope
rating conditions of selective membrane separation processes for wastewater
treatment. The advantage of this technology is that it reduces the amount
of metals disposed into the environment, by removing them from wastewater a
nd concentrating them simultaneously in the stripping stream for re-use in
the plant that generates the effluent. The operating conditions are evaluat
ed solving an optimisation problem, where the set of algebraic and differen
tial equations that represent the component mass balances are formulated as
equality constraints, together with the separation objectives that are pos
ed as inequality end point constraints. The optimisation leads to significa
nt improvements in terms of the flow rate of the effluent treated, showing
the potential of the methodology presented. Insight on the dynamic behaviou
r of the selective membrane separation processes is gained through the sens
itivity analysis. (C) 2000 Elsevier Science Ltd. All rights reserved.