Urine
The Nutrient Recovery Potential, Value Chain, and Its Sustainable Management
2021 年 5 巻 2 号 p. 27-43
詳細
2021 年 5 巻 2 号 p. 27-43
About 80% of all wastewaters worldwide are discharged to the environment without any or with inadequate treatment. This means loss of all nutrients in the wastewater and even if wastewater is treated, there are significant nutrient losses during the process. Human urine forms only a fraction of the wastewater flow by volume, but contains majority of nitrogen and phosphorus, which are essential nutrients for plant growth. To ensure the food security and maximum reuse of nutrients from side streams and wastes, also our own excreta—especially source separated urine—needs to be taken into use as a raw material for fertilizer products. There are several indications of the safe and efficient use of stored urine as a fertilizer in agriculture per se. Issues of concern are pharmaceuticals and micropollutants as well as risk of spreading pathogens when using in urine as fertilizer, but with proper treatment these can be minimized. Furthermore, the environmental benefits of urine separation and reuse are shown in several LCA studies. With an appropriate treatment, urine volume can be reduced, nutrients can be concentrated and recovered to increase the value and enable safe use of the nutrients. Several technologies to treat urine exist already, and can be implemented especially in developing areas, where centralized wastewater treatment is missing. The acceptance of urine separation and reuse seem to be more institutional and related to regulation and existing norms, rather than functionality of the treatment technologies or safety of the end-products. Consumers are more willing to accept the urine use as a fertilizer if it is safe and not increasing costs. In this paper these different aspects of urine separation and use as a fertilizer product are discussed.
