Dear all

This is a short note that we successfully started a reactor for urine stabilization via nitrification at Eawag.

More information about our project on nutrient recovery from urine can be found at www.eawag.ch/vuna .

Kai

Dear all,

In my role as one of the moderators of this forum, I would like to introduce the work performed by the Swiss Federal Institute of Aquatic Science and Technology (Eawag), eThekwini Water and Sanitation (EWS) in Durban, the University of KwaZulu-Natal (UKZN), and the Swiss Institutes of Technology Zurich and Lausanne (ETHZ and EPFL). This work is funded by the Bill & Melinda Gates Foundation (BMGF):

VUNA - Valorisation of Urine Nutrients in Africa
By recovering nutrients from urine in small decentralised reactors, VUNA wants to develop a dry sanitation system, which is affordable for the poor, produces a valuable fertilizer, promotes entrepreneurship and reduces pollution of water resources.
In this collaborative project, the Swiss Federal Institute of Aquatic Science and Technology (Eawag), eThekwini Water and Sanitation (EWS) in Durban, the University of KwaZulu-Natal (UKZN), and the Swiss Institutes of Technology Zurich and Lausanne (ETHZ and EPFL) work together to focus on three important aspects:
1. reactor technology
2. network management
3. socio-economic boundaries

Please visit the project website for more details: www.vuna.ch

I would like to complete the description in my previous post (which had been prepared by Eawag) with a few more interesting informations and ask some questions.

As mentioned in the short description above, partners are the University of KwaZulu-Natal (UKZN) and the eThekwini Water and Sanitation (EWS) Services based in Durban.
Together they are applying a “feedback loop approach” (I picked that up from an old presentation from the Fecal Sludge Management Conference in Durban 2012):

• First, in depth research is done at Eawag (Switzerland);
• Then applied research is conducted at the University of KwaZulu-Natal;
• And finally the role out and application is done in partnership with the eThekwini Municipality.
• Then, the experiences are “looped” back to the lab.

From the homepage, I could not find out what activities are carried out when and where (maybe I just didn't see it). From what I have heard through personal communication of project members, not all of the components are equally researched in all of the 3 locations.

However, it seems that there is quite a lot of work done in the field of "reactor technology and network management" covering following aspects:

• Nitrification
• Evaporation
• Electrolysis
• Hygiene
• Reactor Operation
• Urine Collection
• Performance Modelling

Research looking at “socio-economic” boundaries is done for the “economic feasibility” and social acceptance.
The “economic feasibility” is focussing on:
Understanding how a urine market could operate in Durban
Developing a model which could be adapted for, and implemented in the rest of sub-Saharan Africa, and ideally, laying a foundation for the rapid spread of nutrient-incentivised sanitation plans.

In terms of “social acceptance” the VUNA novel environmental technologies will be accompanied by studies, which investigate the socio-cultural perceptions and factors influencing users’ acceptance. In addition the project plant to investigate and monitor the use of urine diverting toilets and urine-derived fertiliser products as well as to develop appropriate educational activities and awareness material. But no results are available yet.

I have a few further questions, which I would like to ask to the project responsibles:

General:

• When did the project start and when will it end?
• You say you “want to develop a dry sanitation system”: does that cover only the three mentioned components or also additional aspects like toilet design etc. looked at?

Reactor technology:

• In what form do you “harvest” or “valorise” the fertiliser from the urine and what would be the end-product to be marketed in Durban? Is it different for the different technologies (e.g. in terms of nutrient content)?
• What of the reactor technology research aspects (i.e. nitrification, evaporation, electrolysis) is currently researched and where (at what stage)? Can you already say, which technology is the most promising or for the roll out and application in Durban/Sub-saharan Africa and why?
• Can you share already some results in terms of health and ecotoxicology according the end-product?
• What other hygiene aspects do you look at?
• In an old presentation from Durban I also read about “Distillation” – have you done research in this field - and if yes – why did you stop it?

Urine collection and performance modelling:

• What kind of collecting system have been researched and how? And which ones will (or have been?) be tested in application in Durban?

Thank you!

Best Dorothee

By the way: did you know that VUNA in isiZulu (language of project area) means harvest! www.eawag.ch/forschung/eng/gruppen/vuna/organization/index_EN

Hi Dorothee,

Thanks for your interest in our project! To reply to your questions:

Duration of the VUNA project: October 2010 to September 2014
Components: All project components are described on the website www.vuna.ch. With regards to toilet design: the VUNA acceptance studies do address some design issues, although designing new toilet interfaces is not part of our project.

Reactor technology

The nutrient products vary depending on the treatment technology:
1. precipitation: the product (struvite) is a powder that contains mainly phosphorus (12.5 % of mass)
2. nitrification & evaporation: the product is a liquid solution, concentrating all nutrients contained in urine in about 3 % of the initial volume. Nitrogen is present as ammonium and nitrate.
3. electrolysis: the resulting products depend on process parameters, such as electrode material, voltage etc. electrolysis can be used at various stages of the processes.

The location and application of the various processes:
1. precipitation: is researched in Durban only. Struvite precipitation is a very robust process. However, it recovers mainly phosphorus and only a very low fraction of nitrogen (5 %). The drainage liquid of the process still contains high nitrogen and potassium loads.
2. nitrification & evaporation: are researched in Durban and Zurich in parallel. The process has been working well at pilot scale, though needs some refinement for full-scale application.
3. electrolysis: is at a very initial stage. Research is at lab scale on specific components of the process.

Health & Ecotoxicology:
The nitrification & evaporation product is hygienically safe, given that during the process it is heated. Experiments on the fate of micro-pollutants (e.g. pharmaceuticals residues) are currently carried out at the Eawag labs and first results will be available shortly.

Distillation: is a specific form of evaporation. Concerning our process, distillation is currently used in the nitrification & evaporation pilot plant in Zurich and will also be used in Durban soon. In parallel, we are also researching alternative methods (humidification) to evaporate the liquid contained in urine.

Urine collection

Some news on the tested collection systems are to be posted on our website soon. Stay tuned: www.vuna.ch

Dear Bastian

As this is my first post on the forum, I introduce myself: I recently finished my studies in Sustainable Development in Switzerland with focus on social aspects and water issues (water governance, organisational development, social-ecological systems). Now I’m doing an internship at seecon international GmbH in Switzerland, assisting in the SSWM Toolbox (www.sswm.info) and other sanitation related projects. That’s how I came into touch with SuSanA and why I’m getting more and more interested in technical and non-technical aspects of sanitation issues.

I really like your approach of combining large-scale nutrient recovery with a business model for economically poor people. I have some less technical questions:

1. I asked myself, why do you make large-scale nutrient recovery that complicated? Why didn’t you chose the easy option of direct application of (stored and dilluted) urine to the fields? Or in other words: what is the background of the VUNA project? And where do you see its biggest niche or application area?

2.What happens to the faeces?

3.Are there already any results from the research components “economic feasibility” and “social/ user acceptance”?

And by the way: are there any videos available?

Looking forward to your responses and thanks!
Stefy

Dear Stefy,

Thanks for the interest in our project! Here some answers to your questions:

1. Of course, direct urine application is the simplest and most efficient way of urine fertilisation. However, there are several challenges to a large scale application, which we try to tackle in the VUNA project:
a) concentrating the nutrients in about 3 % of their initial urine volume and weight saves storage space and transportation costs.
b) processing the urine into a fertiliser product that does not smell bad improves user-friendliness.
c) processing the urine at higher temperatures kills pathogens and makes it safe to handle.
d) processing removes part of the organic pollutants and can be extended to remove all of them.

2. Faeces treatment is not part of the VUNA project. The eThekwini is running an interesting project to pelletise faecal sludge (www.parsep.co.za/pages/Malaysia-Poster1.pdf).

3. The economic and social acceptance studies are currently carried out in the field and the first results are being processed. We will publish any interesting intermediate and final results on our website www.vuna.ch. Stay tuned!

For videos, check out the "News" box on the left side of our website!

Best regards,
Bastian

Dear all,

I would like to point out the following news on the VUNA homepage:

Complete nutrient recovery
The paper „Udert, K.M., Wächter, M. (2012) [pdf] Complete nutrient recovery from source-separated urine by nitrification and distillation. Water Research 46(2), 453-464.“ is now available as pdf.

Documentation
In this register you find a lot of additional reading material. Now there are also the links to the following videos:

• SRF1 - Einstein: Urin gegen Dünger Engpass (German)
• Smart Studio featuring the VUNA nitrification reactor at Eawag (English)
• SABC -50|50: Excellence in eThekwini (English) (about the infrastructure projects in eThekwini)

Agriculture
Results from struvite crop trials at University of KwaZulu-Natal in South Africa
Fact-sheet: Odindo, A., Bame, I., Buckley, C. (2013) [pdf] Struvite crop trials. Crop and Soil Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa

Results from a plant growth study at ETH Zurich
Poster: Nutrient (re)cycling from human urine [pdf]. Christophe Bonvin, MSc candidate, ETH Zürich, Institute of Agriculture Sciences, Group of Plant Nutrition,


The homepage is updated constantly with new findings. I'll keep you informed.

About me: I am studying Environmental Engineering at ETH Zurich. Since January I am working alongside my studies at Eawag on the VUNA project. I am mainly involved in the communication and the documentation of the project.

I appreciate your interest!

Best regards
Corine