Due to urbanization, population growth, climate variability, and increasing pressure on freshwater resources, water-security challenges in cities are intensifying throughout the worldwide. Wastewater generated in urban areas of most of the countries is rarely reused. For example, only few cities in developing and poor countries are reusing the wastewater. Few developed countries have well developed working models for reuse of wastewater. With technological development in wastewater treatment, urban wastewater is increasingly recognized as a valuable alternative water resource. Recycling and reuse of treated wastewater can reduce freshwater demand, minimize pollutant discharge, strengthen drought resilience, and support the transition towards circular and sustainable urban water systems. Treatment efficiency, emerging contaminants, energy and infrastructure requirements, economic feasibility, regulatory frameworks, public acceptance, potential environmental and health risks are few of the challenges which restrict a developing country to reuse wastewater.
This session invites interdisciplinary contributions addressing scientific, technological, environmental, socio-economic, and governance dimensions of urban wastewater recycling and reuse. Particular emphasis is placed on innovative treatment and monitoring technologies, nature-based and decentralized solutions, resource and energy recovery, removal of emerging contaminants and antimicrobial resistance determinants, risk assessment, water-quality monitoring, fit-for-purpose reuse, and integration of wastewater reuse into urban water management. The session also welcomes studies addressing circular economy approaches, life-cycle and techno-economic assessment, climate-resilient wastewater infrastructure, policy and regulatory frameworks, public perception, and successful case studies from cities across different climatic and socio-economic settings. By bringing together researchers, practitioners, utilities, policymakers, and early-career scientists, the session aims to facilitate knowledge exchange and identify scalable pathways for transforming urban wastewater from an environmental burden into a reliable resource for sustainable and resilient water security.