Master’s thesis proposal – Comparison of different urine-based fertilisers
Urine is an important resource of crop nutrients, actually having a potential economic value of about three times higher than the nutrients that can be utilised from sludge from conventional wastewater treatment plants, since 80% of the nitrogen and 60% of both the phosphorus and the potassium in the wastewater origins from the urine. Therefore, in new city developments close to existing sewers, a good way to increase nutrient recovery from municipal wastewater is to install urine separation systems.
Direct application of human urine as a fertiliser is common practice in many rural areas worldwide. However, direct recycling from urban areas is more complicated. For example, stored urine has a pungent smell and is prone to N losses due to ammonia volatilization, the high water content renders transport to cropping regions costly, and undesired constituents (e.g. pathogens, micropollutants such as synthetic hormones, pharmaceuticals, and their metabolites) pose a health risk to farmers and consumers. Different treatment technologies for stabilisation, volume reduction and removal of health risks ends up with different fertiliser products.
The main aim of the Master´s thesis is to compare three different types of urine fertilisers with a conventional mineral fertiliser in growth experiments.
The experiments will be performed in a greenhouse at the Swedish University of Agricultural Sciences in Alnarp. The three different types of urine fertilisers are a non-diluted stored urine, a urine dry powder and, Aurin, a concentrated urine fertiliser that is already on the Swiss market.