(224h) Simultaneous Design of Water Reusing and Rainwater Harvesting Systems in a Residential Complex

Authors: 
Ponce-Ortega, J. M., Universidad Michoacana de San Nicolás de Hidalgo
Serna-González, M., Universidad Michoacana de San Nicolás de Hidalgo
El-Halwagi, M., Texas A&M University
Nápoles-Rivera, F., Universidad Michoacana de San Nicolás de Hidalgo

Recently, the available water for human consumption has decreased and at the same time the water demands have increased. This way, the problems associated to satisfy the water demands have increased. Therefore, this paper proposes an optimization model for satisfying the water demands in a housing complex involving rainwater harvesting, storage and distribution as well as the simultaneous design of water networks into the housing complex for recycling, reusing, regenerating and storing reused water. Several strategies such as mixing, segregating and storing reused water have been considered. The optimization model accounts for mass and component balances for the different units considered and the problem is considered as a multi-objective optimization, where one objective is the minimization for the fresh water consumption and the other objective is the minimization of the total annual cost accounting for the capital and operating costs for the units involved in the entire horizon. The proposed model accounts for the variability in the water demands through the different hours of the day and for the different seasons of the year. Furthermore, the seasonal dependence for the rainwater has also been considered in the optimization model. A case study of the city of Morelia in Mexico is presented; in this case study the residential complex of Villas del Pedregal was considered. Results show that significant reductions in the total fresh water consumption were obtained with the proposed methodology, and also that the total cost was decreased because the reduction in the cost associated for the fresh water. Also, the results show that the simultaneous implementation for the rainwater harvesting and the recycle and reuse network allows a better solution than the case when only one of these strategies is implemented.