Life cycle assessment of urine-based fertilizer for sustainable agriculture
Dedova, Anastassija (2026)
2026
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202601081112
https://urn.fi/URN:NBN:fi:amk-202601081112
Tiivistelmä
Fertilizer production is a very polluting industry. It especially raises concerns in low-income countries, when the unsustainably mined nutrients are used, while same NPK nutrients are waisted due to the poor sanitation infrastructure. Re-search on the nutrient recovery is growing, but practical decentralized solutions suitable for the regions with limited sanitation infrastructure are still limited. This study aims to address this problem and evaluate the benefits of urine recycling system applied in Ethiopia.
In this bachelor thesis Life Cycle Assessment method was applied to evaluate the environmental performance of urine-based fertilizers from the perspective of sustainable alternative to conventional fertilizers. The study focuses on two source-separated urine management systems applied in Bahir-Dar, Ethiopia. The first scenario is dehydration of stabilized urine in solar-powered dryer, where NPK powder is the final product. The second evaluated scenario is urine storage followed by direct farmland application. The functional unit of the research is treatment of 1m3 of source separated urine per year. The LCA was conducted by using SimaPro software, Ecoinvent database and ReCiPe 2016 impact as-sessment method. Assessed impact categories: global warming potential, terres-trial acidification, freshwater eutrophication and fossil resource scarcity.
The results show that both systems have strong environmental benefits due to conventional fertiliser replacement. However, the dehydration system performs better across all impact categories. The largest difference was spotted in terres-trial acidification impact category due to the ammonia evaporation in the urine storage option. NH3 escape doesn’t appear in the dehydration scenario due to stabilization of the urine through acidification. The dehydration system showed stronger reduction in global warming potential compared to the storage system. Sensitivity analysis shows that type of acid used for stabilization and potential energy input for dehydration are the most influential parameters in the systems. Other assumptions have no significant impact on the system.
Overall, the LCA study showed that solar-powered dehydration of stabilized urine is an effective nutrient recovery solution and sustainable method of fertiliz-er production, that also has a good potential to resolve sanitation challenges.
This thesis consists of this introduction and a scientific journal article, which is attached to the thesis after its publication.
In this bachelor thesis Life Cycle Assessment method was applied to evaluate the environmental performance of urine-based fertilizers from the perspective of sustainable alternative to conventional fertilizers. The study focuses on two source-separated urine management systems applied in Bahir-Dar, Ethiopia. The first scenario is dehydration of stabilized urine in solar-powered dryer, where NPK powder is the final product. The second evaluated scenario is urine storage followed by direct farmland application. The functional unit of the research is treatment of 1m3 of source separated urine per year. The LCA was conducted by using SimaPro software, Ecoinvent database and ReCiPe 2016 impact as-sessment method. Assessed impact categories: global warming potential, terres-trial acidification, freshwater eutrophication and fossil resource scarcity.
The results show that both systems have strong environmental benefits due to conventional fertiliser replacement. However, the dehydration system performs better across all impact categories. The largest difference was spotted in terres-trial acidification impact category due to the ammonia evaporation in the urine storage option. NH3 escape doesn’t appear in the dehydration scenario due to stabilization of the urine through acidification. The dehydration system showed stronger reduction in global warming potential compared to the storage system. Sensitivity analysis shows that type of acid used for stabilization and potential energy input for dehydration are the most influential parameters in the systems. Other assumptions have no significant impact on the system.
Overall, the LCA study showed that solar-powered dehydration of stabilized urine is an effective nutrient recovery solution and sustainable method of fertiliz-er production, that also has a good potential to resolve sanitation challenges.
This thesis consists of this introduction and a scientific journal article, which is attached to the thesis after its publication.