Dear all,

I thought I leave you with some indication about my conclusions regarding the idea of recovering urine as a fertilizer in our region of Seesen/Harz in Germany.  The site visit of the water treatment facility has shown that phosphorous is already being recovered by precipitation and added to the sewage sludge.  The sludge is stabilized anaerobically and used by local farmers.  Nitrogen is gasified in a biological process, potassium is, for the most part, left in the water.

By contrast, it turns out that the Aurin fertilizer as sold in Switzerland is expensive, at least if compared with a comparable chemical fertilizer.  I don't think the situation would be fundamentally different if urine were collected in Germany in a commercial venture.  Since the local water treatment facility is currently working to the satisfaction of the town administration, there would only be limited synergies if urine was collected separately.  In addition, locals are not showing much interest in such an idea.

I think the situation would be different if a fertilizer like Aurin could be sold at a price that is lower than that of chemical fertilizer.  For that to happen, energy prices, in particular the price of natural gas, would have to go up significantly, since prices of chemical fertilizer, nitrogen fertilizer in particular, should be strongly linked to energy prices.  As carbon taxes are slowly increasing the price of natural gas, there should, at some point in time, come a point were the price of a fertilizer like Aurin is becoming comparable to the one of chemical fertilizer.  It would be interesting to come up with a model that could predict at which price the production of a urine derived fertilizer will break even as energy prices are increasing.

Another problem is the current legislation in Germany about excreta derived fertilizers.  I'm not particularly well versed about this issue, but I understand that all you can do with urine under current legislation in Germany is to use it in you own garden.

Regards to everybody,
H-A

Hi H-A
I am not longer with Eawag but with the Eastern Switzerland University of Applied Science and independent.
For the Aurin production, it's best to contact Vuna: www.vuna.ch. The economic viability obviously depends on the legislation (what type of fertilizer) and scale.
Best,
Dorothee

Hello Dorothee,

Thank you for the links.  Unfortunately, the links don't give too much detail about scale, technology, etc. in these projects.  But it seems that the Rich Earth Institute of Vermont, USA, is quite far in terms of scale, and there is a lot of information on their site: richearthinstitute.org

In the meantime, we have performed our visit to the local waste water treatment plant, and the question is arising to what extent the production of urine derived fertilizer from separately collected urine is a profitable business proposition under present conditions.  I am seeing that you are with eawag, the developer of Aurin, the concentrate made from urine.  Could you tell us about the selling prices of Aurin versus comparable chemical fertilizers (NPK plus micronutrients) in Switzerland?  Assuming the selling prices are reflecting all costs of production from collection, treatment to wholesale/retail.  Or would there be some literature about that?

Thanking you in anticipation, and best regards,

Check out:
www.leesu.fr/ocapi/presentation/presenta...ncais/ocapi-program/
reasonstobecheerful.world/france-peevolu...iculture-fertilizer/

We are planning to visit the waste water treatment plant of Seesen (Harz), where I am staying in Germany, in a couple of weeks and discuss options of improvement.  Seesen is a municipality of some 15000 people.  It would therefore be nice if I could get some responses to my question.

In the Susana library, I found a report entitled "Going to Scale with Urine Diversion in Sweden – From Individual
Households to Municipal Systems in 15 Years".  In this article, a project involving 250 houses in the municipality of Vaxholm is described.  However, the article seems to be from around 2010, thus 15 years old.  Would anybody know how such projects have further developed in Sweden?

Hello everybody,

I am wondering whether there would be examples of urine collection systems for agglomerations of thousands of inhabitants.  Would anybody know such examples, and what are the technologies used for collection?

Regards, H-A