An efficient heuristic procedure for the optimal design of wastewater treatment systems

This paper presents a new approach for the optimal design of wastewater treatment systems. An algorithm that can be divided in two parts is proposed for finding global optimal solutions to the problem. The first part comprises a new linear program formulation that is used to generate good starting points for the solution of the general non-linear program (second part). Since the starting point is dependent on the treatment sequence, all possible treatment sequences are considered and thus multiple starting points are generated. The best solution of the several non-linear problems that are solved is then assumed to be the global optimal solution, although there is no theoretical guarantee that this is so. The proposed algorithm has been compared to a global optimisation solver on a set of example problems taken from the literature and the results show that the same global optimal solutions can be obtained in significantly less time when our approach is used. (C) 2006 Elsevier B.V All rights reserved.