Optimal design of reusing water systems in a housing complex

The excessive demand for water worldwide has promoted the development of strategies for its efficient use. The industrial sector has developed several water recycle and conservation strategies that have led to reduction in the fresh water consumption and the wastewater discharged to the environment. Comparable environmental and economic benefits can accrue as a result of adopting similar water strategies in the residential sector. This paper proposes an optimization formulation for the design and operation of networks for the recycle, regeneration, and storage of water in residential complexes. Segregation of wastewater streams is considered to avoid the mixing of streams with different qualities prior to treatment and recycle. The optimization model accounts for the simultaneous minimization of the total annual cost and the fresh water consumption. A case study for a residential complex of the city of Morelia Michoacán in Mexico is used to apply the proposed approach. The results show significant economic and environmental benefits (such as reduction of natural resources consumption and waste generation) for the implementation of the proposed approach. The developed optimization model also enables tradeoff between the considered objectives.