Optimal design of total integrated residential complexes involving water-energy-waste nexus

This paper presents a multi-objective optimization formulation for enhancing the sustainable development of a residential complex. The approach accounts for the water-energy-waste nexus of the complex and enables various pathways for system integration. For conserving the fresh water demands, the proposed model includes the synthesis of water networks while accounting for wastewater reclamation and recycle and rainwater harvesting. The proposed model also incorporates the optimal design of a residential cogeneration unit to satisfy the demands for electric power and hot water. An absorption refrigeration system is considered to utilize waste heat and provide the needed refrigeration. The emitted carbon dioxide is fed to an algae growth system, which is integrated with the use of reclaimed water. A solid-waste gasification system is considered to provide electric power and heat to the residential complex. The optimization approach accounts for all the interactions of the involved units and for the seasonal variabilities of the system. A case study for a residential complex of Mexico is solved.