Techno-economic Analysis of a Sustainable Ablution Greywater Recycling System for Toilet Flushing
Abstract
In arid and semi-arid countries, it is required to identify alternative potential sources of water and develop sustainable technologies for their recycling. A large amount of less contaminated ablution greywater (AGW) is being produced at the mosques in all Muslim countries including Kingdom of Saudi Arabia (KSA). Therefore, AGW certainly possesses significant potential for recycling. In this study, a simple and cost-effective sustainable ablution greywater recycle system (SAGWRS) is proposed to collect, treat and recycle the AGW within the periphery of a mosque for toilet flushing. A conceptual model for SAGWRS was developed and evaluated through techno-economic analysis. The SAGWRS consists of a AGW collection and storage system, low cost ceramic filtration unit, activated carbon adsorption column, chlorine dispenser, and overhead tank to collect and distribute treated AGW. The SAGWRS meets the water quality standards for toilet flushing as well as for irrigation. A simple operation and maintenances procedure made the system sustainable and cost effective. The estimated cost (0.7-1.0 US$/m3) of the SAGWRS was found to be considerably less than the municipality water cost (1.71 US$/m3) in KSA. SAGWRS proposed in this study would be a prospective recycling practice of AGW in KSA for sustainable development. Based on the techno-economic analysis, the proposed system provides a sustainable approach of water conservation by on-site recycling of AGW in Muslims countries around the world.