A Solution Procedure for the Design Problem of a Multiple Treatment Plant System along a Stream

Abstract

AbstractThe design problem of liquid waste treatment plants in a multi-plant system along a stream entails the selection of a sequence of unit operations for each plant, as well as the determination of each operation’s waste removing efficiency, so that the dissolved oxygen standards along the stream are met at minimum cost. The suggested solutions have so far been partial and sub-optimal since they consider only the efficiencies on a fixed sequence of unit operations, neglecting the question of choice among them. This paper outlines an efficient two-phase procedure for completely solving this multi-plant system problem by determining for each plant both the best set of operations and their efficiencies. First, a network algorithm is developed for generating concave cost-efficiency curves for each plant such that each plant efficiency level corresponds to the optimal rather than to a pre-specified fixed sequence of operations. Second, a linear programming model with concave and separable objective functio...