Treated wastewater irrigation: unlocking sustainability in agriculture and food security—a comprehensive review

Water scarcity caused by high population growth and climatic change has been a significant challenge particularly in arid regions. This current review explores the potential of treated wastewater (TWW) as an alternative water source for agriculture offering a sustainable solution to reduce pressure on freshwater resources and support long-term environmental sustainability. Moreover, TWW has been shown to improve soil fertility, enhance crop growth and reduce their dependence on chemical fertilizers by supplying essential plant nutrients as well as significant amounts of organic matter. Moreover, it improves water use efficiency and contributes to increased crop production, with positive effects observed in various crops. Nevertheless, there are some issues that are associated with the application of TWW in agriculture, such as social perception, lack of infrastructure, and the fear of contaminants like heavy metals, pathogens, and microplastics, which can be deposited in soil and enter the food chain. This review explains that effective treatment technologies are necessary to ensure the safe use of TWW, minimizing environmental risks and protecting human health. Another important point discussed in this review is the increasing use of TWW worldwide especially in the water-stressed regions, where it has proven to be an effective, solution for alleviating water scarcity.