Spatially constrained interplant water network synthesis with water treatment options

This work incorporates treatment strategies into an interplant spatially constrained water network synthesis problem. The approach enables synchronized treatment, and wastewater re-use within industrial zones that involve multiple processing facilities with geographic proximity. We have previously introduced and illustrated spatially constrained interplant network synthesis for water integration via the application of direct recycling techniques. This work expands the representation, by accounting for constrained water transport, to and from treatment facilities, through assigned service corridors for any given industrial plot layout which potentially could involve miscellaneous plant and treatment facility arrangements. The execution of Dijkstra's Algorithm (Dijkistra, 1959) obtains the best routes for source-to-sink, source-to-treatment, and treatment-to-sink in a similar manner to our previous contribution, thus providing optimum distance information to be used for the planning of cost-effective piping layouts. In this study, both centralized and decentralized treatment options were introduced, and a MINLP optimization problem was formulated to determine optimal water stream allocation options. As an illustration, a case study involving an industrial city layout consisting of a total of three plants, five water sources, and five water sinks distributed in between, has been carried out. A single central treatment facility that is shared amongst all plants was enabled, and each plant was associated with its own decentral treatment option. The results discuss the interplant water network design obtained, which involves both treatment and direct reuse allocations.