Quality of the products

Treatment of urine by MAP crystallisation results in a product which contains the nutrients of the source-separated yellowwater stream and which can be used as a fertiliser in agriculture.

A central aim of the measures for nutrient recovery from wastewater streams is to guarantee the best possible separation between valuable substances and pollutants. This is necessary to ensure a high quality of the recycled nutrients. Ideally, the concentration of pollutants in the recycled product should be in the same concentration range as is found in mineral fertilisers; this aspect will be assessed within the project component “quality of products”.

The concentration of investigated pollutants will be compared with the existing legal limit values as well as with the limit values under discussion.  The main focus will be on the fate of trace elements as well as ultra trace elements during and after the treatment.  In particular, pharmaceuticals must not be found in the fertiliser product.

This focus point is led in common by the University of Bonn and the RWTH Aachen.

Storage of Urine

It is known that pharmaceutical residues already degrade during the storage of urine. This degradation within the storage tanks of GIZ will be quantified for the detected pharmaceutical residues according to the respective storage conditions. Additionally, storage conditions will be simulated (e.g. variation of pH value) in laboratory tests. The results from those tests will be used for potential optimisations of urine storage.

This focus point is led by the RWTH Aachen.

Grey- and brownwater treatment plant

Besides the measurement of standard parameters such as nutrient content, the greywater permeate is also analysed regarding the removal efficiency of surfactants
The brownwater permeate is analysed on the same standard parameters such as nutrient content as well as on pharmaceutical residues. Since the majority of those residues is excreted via urine, the load is neglectable in the brownwater. Finally, to sample the hygienic characteristics of the permeates of both systems, microscopic tests are conducted to assure microbiological harmlessness. 
 

An overview of the latest project results in this component regarding first analysis results of the pharamceutical residuals and contained microbiology in the permeates was presented at the last meeting in February 2012. There is an English summary available which includes the most important slides of this component:
English-summary (2,43 MB)