Stochastic Optimization Model for Sustainable Water Treatment with Minimal Energy Use

This paper develops a stochastic model to address uncertain (non-deterministic) water demand and supply that supports decisions regarding which water treatment systems to select. The optimal decision is the one that meets the water demand and achieves the minimum energy use or cost. The model constitutes the first stage of a broader research plan that aims to understand the dynamics among the water, energy, and food nexus and applies to a closed-loop, controlled environment system. The optimal values of decision variables are calculated for two different climates; one is relatively cloudy (with an average solar radiation of 3.6 kWh/m²/day) and humid (with an average rainfall of 1,000 mm/year) and the other is sunny (with an average solar radiation of 5.6 kWh/m²/day) and arid (with an average rainfall of 100 mm/year). The results of the study provide a basis for recommendations regarding actions to improve technological problems and processing approaches to optimize water treatment with minimal costs and energy inputs.