Dear Lilian, dear Scott

Please find the answers to your questions below:

1. Costs of the reactor
We did a rough calculation based on the expenditures for the pilot plants in Dübendorf and Durban. Based on this calculation, a pilot plant costs about 200 EUR per person. Approximately half of this costs are for the distiller and the other half for the nitrification reactor, the process control and all other components. For example a pilot plant, which can serve 400 people would cost approximately 80,000.- EUR. However, this value should be taken with a grain of salt, because a pilot plant is substantially more expensive than an industrially produced standard reactor. We expect that the price will be significantly lower in the future.

2. Urine value chain
A final assessment of the urine value chain in the VUNA project cannot be given yet, because the research is not completed. However, you can find our current findings on our homepage: www.vuna.ch.
In the STUN project (www.eawag.ch/stun) we also investigated the direct use of urine as fertiliser. This can be a valuable option in rural areas, especially if drip fertigation systems are used.

Best regards, Kai

Kai,
I would be very pleased if you could give us more information about about the urine vale chain since i am using the urine from 20,000 students to grow apples and cherries.

Please refer the details to
forum.susana.org/forum/categories/91-pro...-successful-business )
best regards
Scott

Hi, Ben,

Good questions. It seems to me so important right now that we get UDDTs field tested in industrialized countries. (Better to do field trials at home before doing them elsewhere.) Public toilets are not the easiest way to launch UDDTs but the educational effect could be terrific. We're looking for successful models to advocate for with local leaders. I'm interested in what part of France you're working in.

Carol

Hello,

I have a few questions about the cost as I couldn't locate them in the documentation:

How much does the reactor cost?

The one in Switzerland, and the one in Durban?

How about the distiller?

Hi Dorothee

In the interest of keeping this thread dedicated to the main VUNA findings, I started a new topic called "Monitoring and Evaluation" and replied to you over there: forum.susana.org/forum/categories/142-up...oring-and-evaluation

Let's keep the conversation going!

Liz

Dear Femi

One approach for direct use of urine is fertigation. By using trip irrigation pipes, you hardly loose any ammonia by volatilization and can supply the urine directly, where it is needed. We tested this approach in Nepal together with Marjin Zandee. You will find more information here: www.eawag.ch/forschung/sandec/gruppen/EW...m/stun/drip/index_EN

Kai

I read this posting with delight.
I and a collague have been working on sanitization of urine and use of farms with some farmers union in Osun and Oyo States in Nigeria and currently considering resources reuse in a waterless toilet system, currently being designed to collect urine seperately, sanitized and used while faecal matter shall be composted and fortified to ensure essential nutrients are available to crops.

If we can have additional information on the valorisation, it will help us further in thinking about the design and piloting further in my research team in Nigeria.

Dear Ben

I am curious to learn more about your project! Actually, we are looking for partners to optimize and construct the reactor.

In the VUNA project, we have two pilot plants, one in Durban and one at Eawag in Dübendorf/Switzerland. The reactor at Eawag has been producing urine fertilizer for more than 2 years now and we understand the process well enough to construct further reactors.

More details about the reactor at Eawag can be found here:
www.eawag.ch/forschung/eng/gruppen/vuna/...ure_completeRecovery
www.eawag.ch/forschung/eng/gruppen/vuna/...r_operation/index_EN

Best regards, Kai

Hi Elizabeth et al.

I would like to give you some answers on the questions marked in red. Thank you, Liz, for replying to the question about the incentives.

Comparison of energy requirement for the urine reactor
The urine reactor installed in Forum Chriesbach requires about 125 Wh/L or 6.5 W/pers (assuming 1.25 L/pers).
This is close to the energy, which is required to treat wastewater in a modern centralized wastewater treatment plant with nutrient removal. Or to compare it with household devices: the most efficient fridges (EU norm A+++) have about the same continuous power demand (6.7 to 7.8 W), while a standard fridge (EU norm A) requires more than double (at least 17 W).
In our setup, the distiller is already energetically optimized, but we could reduce the energy by optimizing the aeration of the nitrification reactor or by removing part of the water with reverse osmosis.

Nitrogen loss during nitrification/distillation
During nitrification, hardly any nitrogen loss could be measured (less than 3%). The major problem for nitrogen loss from urine is actually urine storage and transport. Before treatment, a large fraction of the nitrogen in urine is volatile ammonia. Half of the nitrogen can easily be lost during storage and transport, if the containers are ventilated.

Optimizing urine collection with a computer model
The computer model I mentioned during the Webinar is described in some more detail in a brochure, which can be accessed here:
www.eawag.ch/forschung/eng/gruppen/vuna/...NAbrochure_modelling
At the moment, the computer model only includes parameters of the urine collection chain, such as the filling rate of the urine tanks in the household, frequency of collection, number of intermediate tanks, salary of fieldworkers, costs for urine transport with a truck etc. Many parameters have a wide range of values, e.g. the urine production per person can vary widely. To account for this variability, the model uses statistical distributions.
The model can be used to estimate the amount of urine and costs for different collection scenarios. For example, the model can tell you, whether it is more efficient to collect urine two or four times per week. If you collect it only two times, you might lose some urine, but you have lower costs for transport.

Business model and overall cost analysis
I also mentioned that we are working on a business model, which includes other elements of the "urine value chain", such as the potential value of the fertilizer and the costs for urine treatment reactors. The costs for many of these elements can only be estimated at the moment, e.g. by calculating the value of nutrients in different kinds of fertilizers or by estimating the costs of a industrially produced urine treatment reactor based on the costs of pilot reactors.

Best regards, Kai

Dear VUNA researchers,

I’d like first to congratulate your work and especially the energy you put in sharing it. I’m always so greatfull for this forum to exist and all the person in the shade at Susana doing a great work.

I’m currently working of a UDDT public toilet in france and would be very interesting in testing your reactor in a very busy center town place type train station / main square of the city / etc … which can be easily 200l/day.
I believe some townhall financing is reachable as well as some local chemist universities partnerships, the communication made out of this kind of installation would be powerful and therefore many green party local leaders would support such project. The idea would be to convert urine on site (extra liquid in the sewer network) before transportation, thus reducing the transport costs to nearby fields. We already planned to put some solar panel for ventilation-lights and the daily cleaning of the toilet would allow a great care and monitoring of the system.

My question is therefore :
• At the current development of the reactor, what is its range of price ?
• Do you plan to do any trial in an European context ?
• Are you looking for new partnerships or do you focus first on the proof of concept with VUNA before spreading it ?

Thanks again for sharing your discoveries and I wish you the best of luck in the revolutionary technology you develop !

Ben

Dear Marijn and Liz

I am also happy this discussion comes up here.

Sustainable sanitation has five goals including health, financial issues, environmental, technical issues, socio-cultural and institutional issues.
The functionality of these goals have also been nicely illustrated by the functional sanitation ladder (see also www.susana.org/images/documents/04-meeti...anitation-Ladder.pdf).
To reach each of this goal has a benefit to the direct beneficiaries of the system as well as for the wider society. This benefits are not easily measurable in monetary terms and expressed in financial viability of one or another technology or sanitation system choice. However, these benefits have all a positive impact on a national economy what justify the public investment in the implementation of a system.

Unfortunately, monetary values are often more easy to grasp, in particular for decision makers.
One big question I am personally interested in is how the sum of benefits of a given system in a give context can be communicated to policy and decision makers when not in monetary terms? Or should it be done in monetary terms? And then how far can we go in evaluate and measure of benefits based on the functionality of a system?

Liz, you mention some numbers. Have you done any cost-benefit comparison of different systems in Durban and if yes, how far did you go in cost-calculations regarding components of different systems (e.g. awareness raising campaigns, user training, etc.)?

Regards

Dorothee

Dear Elizabeth,

Good to see you here on the forum!

I think you make an interesting point in your post, which I would like to highlight in a broader perspective.

Especially in older ecosan brochures there is often an emphasis on how well a UDDT, or other ecosan technology, can pay itself back. I think this is not always the correct perspective. In Nepal I see a similar discussion around using biogas technology for organic solid waste management, where people have unrealistic expectations regarding financial viability (often also to convince donors to give them money!).

I think it would be helpful to more widely acknowledge that waste management (in a wider sense) will almost always cost money and that only part of the cost can be offset by energy or nutrient recovery. And that thus there will almost always be a part of the cost that will have to be made "public", either through direct investment of people and companies or through taxes.

Regards

Marijn