Towards development of a decision support tool for conceptual design of wastewater treatment plants using stochastic simulation optimization

Available treatment technologies for wastewater are diversifying as the industry is undergoing a paradigm shift from considering wastewater as a waste to treat to an increasingly valuable source for energy production and resource recovery. With the purpose of addressing the problem of determining optimal plant network for wastewater treatment plants, we develop a new decision support tool (SPDLab) relying on a novel simulation optimization based process synthesis framework and a library of rigorous process models.

The capabilities of SPDLab are demonstrated with a case study for designing an energy surplus WWTP. The Benchmark Simulation Model No. 2 (BSM2) (Gernaey et al., 2014) plant layout is populated with additional options for primary treatment technologies, such as a rotating belt filter with or without polymer addition, and mainline treatment options including also fixed film activated sludge (IFAS) technology.

A side stream treatment with partial nitrification-Anammox process is also included in the superstructure. Results obtained show that the combination of efficient carbon recovery with main stream Anammox and anaerobic digester produces the most net energy among the investigated alternatives.