Abstract
Agricultural wastewater contains high concentrations of nutrients such as nitrogen and phosphorus, which, if discharged without proper treatment, can lead to environmental problems, including water eutrophication and soil pollution. These nutrients, however, also have considerable potential for resource utilization. Efficient recovery and conversion into fertilizers can strongly support sustainable agricultural development. In recent years, significant advances have been achieved in nutrient recovery and fertilizer production from agricultural wastewater, encompassing physical, chemical, biological, and combined methods. These technologies have been widely applied in the research and production of slow-release and liquid fertilizers. This paper systematically reviews the fundamental characteristics of nutrients in agricultural wastewater, the principles of various recovery technologies, and their specific applications in fertilizer production. It also examines the environmental and economic benefits of these technologies, as well as their limitations and the challenges encountered in practical implementation. Furthermore, the paper outlines future research directions, aiming to provide a systematic theoretical foundation and technical guidance for the resource utilization of agricultural wastewater, thereby promoting green agriculture and a circular resource economy.
