Based on regional statistics, the amount of nutrients generated in the North of Sweden was large enough to replace the commercial fertilisers used in the same region. Regarding the environmental impact, the Global Warming Potential (GWP) was calculated for two scenarios of production of fertilisers. The scenario involving the treatment and concentration of urine was found to have a GWP lower by one third compared to the conventional scenario of commercial fertilisers production. In a sensitivity analysis, longer lifespans of materials and use of hydropower lead to a GWP lower by two thirds with urine than commercial fertilisers. The main contributors to the GWP were the production of materials and the generation of electricity, highlighting the importance of considering durable materials and to switch to renewable energies. The potential of source-separating systems was considered as an important step for the recovery of nutrients from human excreta.
This study was carried out by Laureline Turlan, student at INSA Lyon, within the ON-SITE project which is funded by InterregNord.