Optimization of Overall Network of Water-Using and Treatment Units

The concept of process integration has gained more and more attention in the last years due to its beneficial results in the framework of freshwater minimization, costs reduction and environmental impact diminution. The optimization of an integrated water-using (WU) and treatment units (TU) network is addressed in this paper, by targeting for maximum treated water reuse as a considerably better alternative to fresh water consumption. The mathematical model of the integrated water network (IWN) is based upon total and contaminant species balances. They are written for each and every unit and are subject of restrictions of inlet and outlet contaminant concentrations. The optimization problem is carried via Genetic Algorithms. An industrial example was analyzed with respect to contaminants' mean availability and network reuse index to point out the benefits of integration.