Reclaimed urban wastewater for industry: blending strategies for circular economy implementation in the Principality of Asturias

Abstract Water scarcity presents a critical challenge to industrial growth, environmental sustainability, and effective resource management. This study explores the potential of reclaimed water from the Villapérez Wastewater Treatment Plant in the Principality of Asturias as a sustainable solution for industrial applications, including high-demand sectors such as hydrogen production. With approximately 325 water-intensive companies in the region, the adoption of reclaimed water offers a viable alternative to potable water, reducing pressure on freshwater resources. The research focuses on producing high-quality reclaimed water that meets rigorous industrial standards while minimizing energy consumption, a significant technological hurdle. A treatment system combining ultrafiltration and reverse osmosis was designed to achieve the required water quality. By blending ultrafiltered and osmosis-treated water, the system produced water with low conductivity, reduced salinity, and optimal chemical and microbiological properties suitable for industrial use. The project aligns with Asturias’s Circular Economy Strategy, demonstrating how wastewater reclamation can support industrial demand without compromising drinking water supplies. Within the framework of the regional project led by the Principality of Asturias, a comprehensive distribution network spanning 60 km has been designed to deliver reclaimed water to key industrial zones in Avilés, Gijón, and Oviedo. Pilot studies confirmed the effectiveness of the treatment process, with reclaimed water consistently meeting or exceeding regulatory standards for industrial use. This initiative not only addresses water scarcity but also promotes resource conservation and environmental stewardship. By integrating reclaimed water into industrial processes, this pilot project provides a scalable model for sustainable water management, advancing the circular economy and fostering a balance between industrial growth and ecological preservation. The results highlight the potential of reclaimed water as a strategic resource for non-potable industrial applications, contributing to a resilient and sustainable water supply system. This approach underscores the importance of innovative water reuse strategies in achieving long-term environmental and economic sustainability. Graphical abstract