Lunch Seminar “Urine and faeces as NPKS fertilizers in the bioeconomy”

Abstract:

The plant nutrients that we consume with our food leave us by our urine and faeces. To minimize environmental impact and maximize resource efficiency, the nutrients should be recycled back to agricultural land. The ratios of nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) in blackwater (urine+faeces+flush water) correspond well to what the harvest of wheat and other crops remove from the fields. Blackwater contains only low concentrations of pollutants, thanks to good food hygiene. This, together with the necessity to fertilize our fields in order to feed the increasing world population, means that production and use of complete fertilizers from blackwater are essential for transitioning towards sustainable agriculture.

Efficient recycling of N, K and S, and not only of P, is well motivated. The production of plant available N uses large amounts of natural gas, a very limited fossil resource, and emits large amounts of greenhouse gases. Additionally, the economic reserves of P, K, and S are limited.

For efficient recycling of excreta nutrients, high nutrient concentration and high value products are important. Two very promising options our group researches are making a dry fertilizer from urine and making feed protein from faeces and organic waste, and thus partly bypassing the field.

Welcome! 
Katrin Rychel, Minh Anh Nguyen and Jenna Senecal