The evolution of wastewater reuse for irrigation: Lessons learned and future directions

Sustainable water management is essential for tackling water scarcity, food security, and environmental degradation amid climate change. Wastewater reuse in agriculture is a vital strategy, with varied implementation and outcomes globally. This review synthesizes global findings on wastewater reuse evolution, focusing on technology, impacts, and governance from a sustainability viewpoint. The analysis reveals significant benefits, such as reduced freshwater use, nutrient recovery, increased agricultural yield, and contributions to circular economy and Sustainable Development Goal 6. Nonetheless, challenges persist, including public health risks, soil salinization, contaminants, high costs, regulatory issues, and social acceptance. Comparative studies indicate that water stress, economic capacity, and institutional strength significantly affect reuse system sustainability. A notable gap exists in sub-Saharan Africa, where informal and poorly regulated wastewater reuse is prevalent. The review underscores the necessity for integrated management, suitable technologies, digital monitoring, and unified policy frameworks to enhance sustainable wastewater reuse for irrigation.