Environmental Performance of Building Integrated Grey Water Reuse Systems: Life Cycle Assessment Perspective

The scarcity of freshwater available is of grave concern to the policymakers. The hefty consumption of water by the building sectors around the world has led to the lookout for a feasible and sustainable approach of water conservation techniques. Today, water reclamation methods, like greywater recycling, are being highly promoted by the green building rating systems and environmental agencies. This paper evaluates the life cycle environmental advantages of deploying a building integrated greywater recycling system compared to the conventional water treatment systems. For the study, a submerged membrane bio-reactor (SMBR) system is chosen as the greywater treatment technique. It is assumed to be deployed at the female student housing located in the Education City of Qatar. Qatar presents an interesting and unusual case study to the international audience as 99% of the water consumed is obtained from the sea after a rigorous desalination process. The study compares the LCA of a building integrated greywater treatment system to the conventional desalination process used in Qatar. The SMBR system is estimated to produce 8.04 kg CO₂ less than the desalination system. The results of this study indicate an on-site greywater reuse system to be advantageous in Qatar, and precisely quantifies the environmental impacts of deploying this method. These results are of high relevance to the policymakers in the Middle East and North Africa (MENA) region to make a consequential impact on the present condition of the water crisis.