Sustainable water management through integrated technologies and circular resource recovery

Abstract

Sustainable water management increasingly necessitates integrating advanced treatment technologies with circular economy principles to achieve zero-discharge targets. Conventional physical, chemical, and biological treatment processes have evolved with a focus on process efficiency and disinfection. However, to meet the broader goals of the UN Sustainable Development Goals (SDGs), which include resource recovery, waste minimization, and environmental protection, there is a pressing need to move beyond standalone systems-based water treatment technologies. This requires drivers such as regulations, strict enforcement of compliance and institutional support for a holistic integration of technologies that reinforce the water-energy-sanitation (WES) nexus. Emerging hybrid systems are mostly membrane-based separation, advanced oxidation, and bio-electrochemical processes, not only for contaminant removal but also for energy generation and valuable resource recovery, such as fresh water, nutrients and metals/materials. The use of low-grade industrial waste heat and renewable energy sources, coupled with energy storage technologies, enhances the sustainability and resilience of these systems. Radiation-based sterilization, real-time monitoring using sensors, and closed-loop water reuse systems further support zero-discharge operations and regulatory compliance. Desalination brine and sludge management, end-of-life membrane recycling, and nutrient recovery are critical components requiring integrated solutions. When designed effectively, these systems reduce carbon footprints and environmental burden, recover valuable water and resources, and support decentralized treatment models. This perspective explores how multi-separation, energy-integrated, and resource-recovering technologies can be synergistically combined to create closed-loop water treatment systems. The zero-discharge infrastructure and strengthening interconnections across water, energy, and sanitation domains would achieve the objectives of 11 of 17 SDGs directly or indirectly.