I think the real problem is that those bulbs go rapidly out of style which energy saving fluorescent and LED ones. Here in Uganda you will actually have trouble even finding the old round ones in a store.

Dear Detlef,

It is true that Andreas didn't sign with his name in the post above, but he is definetely "anonymous". Just click on his photo to the left of his post. This takes you to his forum profile page where you see his full name plus contact details. Furthermore, you can click on the tab called "posts" where you see his previous posts (the last 20). In one of them, he gives a detailed introduction of himself, see here:
forum.susana.org/forum/categories/35-bio...enyan-primary-school

I am just writing this in case others are not aware of this option either on how to access previous posts by a certain user.

As far as the eco-lily goes, no this "design" or this "name" was not invented by Andreas. I think it was actually the NGO Sudea in Ethiopia who came up with it or who coined this name, and this could be as far back as the late 1990s, or early 2000s.

Here is another photo of such a simple urinal from 2008:

Cheap waterless urinal in Burkina Faso by Sustainable sanitation , on Flickr

I still have my doubts about such a light bulb or tabletennis ball arrangement in the longer term. I suspect that over time, urine stone deposits will build up on the funnel which would make the fit of the ball in the funnel less "snug". Also, the bulb could break and the ball could "disappear". But maybe I am totally wrong with this. Does anyone else have long-term experiences with such a simple odour seal?

Regards,
Elisabeth

Dear ande1978, Anonymous?
Very clever idea to use old bulbs or similar, I am guessing at least a good smell reduction will happen.

I like your approach for simplicity and would like to know more about YOU. "...given away the eco-lily design..." Is it meaning this bulbs idea "eco-lily" been your own idea to start with?
All the Best
Detlef SCHWAGER

I have tried and given away the eco-lily design with the light bulb several times here in Kenya since non-working or old light bulbs are usually available. To date, my friends like the idea and use them.

Dear Julius, actually this seems to be the final price by Keramag. But thanks to Bernhard I found this valve by CULU for 17,95€. www.culu.eu/zubehoer/geruchsverschluss-fuer-wasserlose-urinale/

My experience with the ping-pong ball was very positive as well. People in Kenya reported that the only time when smell occurred was during the replacement process of toilet containers.

I really like the idea to solve the smell problem with the urine pipe that goes all the way to the bottom of the urine canister. For MoSan it could make the emptying a bit more complicated if this pipe is connected to the seat (as it is on the SuSan unisex urinal), since the seat cant be placed evenly on the ground anymore. But one idea would be to have the pipe within the urine canister and the seat attaches to it. I will definitely think about this idea and try it out! Many thanks for this advice!

With the oil layer Im a bit concerned about the cleaning of the container and the direct reuse of urine? But it also seems worth a try.

Many thanks and all the best,
Mona

This reminded me of a video that I once made with my students at UNESCO-IHE in Delft six years ago where I explain how the blocking fluid in a water less urinal (from Uridan from Denmark) works:



In the video, I also show the Keramag rubber tube valve which is mentioned above and show how to take it out, clean it and re-insert it.

Amazing: Six years on, and the video is still relevant (and a bit embarrassing for me ) - the topics still remain the same...

Hello Kai,

Ahh good to know that it is a proven technology. However I don't see that your concerns apply to the specific case I mentioned, e.g. in a UDDT there is no flushing thus no huge loss of oil during normal operation and with the mentioned down-pipe to minimize the surface area not much oil is needed. Alternatively some sort of siphon could also be used to minimize the surface area.

Edit: Ahh I should read more carefully: cleaning water... hmm yes that is probably an issue, but at least for the small mobile toilet Mona is working on that should be ok regardless. Besides, in a urine-reuse UDDT you would usually not want that much water in your urine storage either.

Of course it would need to be replaced when the tank is changed and probably replenished during normal use also from time to time, but I don't think that is an issue in a normal household where cooking oil (even old one) can be used.

At least I assume normal cooking oil mostly blocks the degassing of the smelly NH4/NH3+ (which as a polar substance dissolves well in water, but not so well in oil), or are those "floating organic liquids" of a special composition?

Hi Julius

Floating organic liquids were used by waterless urinal companies for years. Recently, many of them have changed to other types of smell stop, for example Ernst, a company, which was mentioned by Elizabeth above.

In public toilets, one of the problem is that the oil layer can easily be flushed away with cleaning water.

I assume that the system is not well suited for UDDTs with urine tanks, because the organic liquid would have to be replaced everytime, when the tank is emptied. Furthermore, a lot of liquid would have to be used because of the large surface.

Kai

Not sure were, but a while ago I also read about using an floating oil layer as a smell stop, e.g. similar idea to the ball valve but with oil. It could probably be combined with the all the way to the bottom pipe idea Elizabeth posted above.

Dear Mona, and others,

Looking at the pictures above, I was just wondering whether using a piece of bicycle tube would be a way to make a more durable solution then the condom trick? Has anyone tried this?

rgds

Marijn

Oh and one more thought: Mona, do you have a cut side view drawing of your MoSan toilet? I would like to see how the urine goes from the collection bowl to the canister below.
What I have heard from others is that odour can be minimised if the urine pipe is submerged into your container all the way to say 2 cm from the bottom. This way you reduce the available urine surface area to just the surface area of the pipe.

I think this is how Karsten from SuSan Design in Norway solved the problem for his beautiful uni-sex waterless urinals (which have not yet been mass produced unfortunately) - these photos are from a trial in Kenya which GIZ co-financed (more photos are available in the flickr set, just click on one of them below or here: www.flickr.com/photos/gtzecosan/sets/721...909/with/5196378446/):

Girls Urinal 6 - Stones to help younger girls to use the urinal by Sustainable sanitation , on Flickr

A young girl in one of the households that tested the urinal for 2 weeks by Sustainable sanitation , on Flickr

Assembling 4 SuSan Design by Sustainable sanitation , on Flickr

Regards,
Elisabeth

There's always that trade off between cost and quality... I think the ESS costs in the order of 15 Eur, and they need to be manufactured to a high precision with Swiss (!) machines to work with the silicone otherwise it doesn't work properly...

Krischan mentioned the "condom trick". In the interest of those who don't know what he means with that: it's about using a condom that is cut off at the top. See this photo which is also from our great UDDT technology review:

WECF Urinal condom by Sustainable sanitation , on Flickr

My take on the story is that it might work in cold climates (tested in Eastern Europe) but not in hot climates (experiences by Heike Hoffmann and Christoph Platzer in Peru).

This is what we wrote about it in the technology review:
susana.org/lang-en/library?view=ccbktypeitem&type=2&id=874

A simple supplementary odour control measure has been used in Eastern Europe by the NGO WECF on conventional flushing urinals that were retro-fitted for a waterless operation. All but one of the urinal’s drainage holes were sealed and a condom with a small hole cut into the tip was fitted over the outflow piping. This simple setup allows the gravity driven drainage of urine into the discharge piping, but prevents the migration of odours from the urine collection vessel and piping into the UDDT super-structure (see Figure 15). However, practitioners working in warm climates have reported that these condoms fail to work because they stick together within a short time, for example if the toilet is not used for a day.

Christoph Platzer also wrote about it in this thread: forum.susana.org/forum/categories/34-uri...es-odour-issues#3678

At least peruvian condomos were too sticky. they glued together. Who has tried them out as well?
But our experience is...over 400 simple waterless urinals (fiberglass)... you just have to care that the urine flows down, no point at all where it could accumulate. No 90° bending (VERY IMPORTANT, as easily at that point you have "ponding"), strong slope, the proper urine piping is crucial. We had some problems with odour, but ALL related to the mentioned errors.

So our experience is: it is not necessary to have smell stops in cases of individual toilets or a small number of toilets.

Another idea is to use charcoal, I have no first-hand reports on this, other than what we wrote here:

A further option for odour control at the point of the user interface may involve the use of charcoal, which is supposed to have the ability to adsorb urine odours. Charcoal contained in a mesh bag and placed directly in the urine-diverting section of the user interface has been applied in the Philippines, and shown to be an effective means of odour reduction (Gensch et al., 2010). The adsorptive capacity of the charcoal will be gradually exhausted, and the charcoal thus requires regular replacement.

And we also wrote about the idea with the ping pong ball:

It has been suggested that another option to control odour could be a plastic ball (size of a table tennis ball) which is placed in the urine funnel of the urine diversion pan and could act as a one-way valve to prevent back-flow of odours (see Figure 51, right). When a sufficient volume of urine enters the funnel, the ball would float, allowing for the drainage of urine. When the urine has drained completely, the ball would return itself atop the drainage pipe, preventing odour from migrating into the toilet cubicle. The authors doubt that this system could work reliably, and no detailed experiences with this concept have been reported to our knowledge.
A one-way valve consisting of two silicon curtains or a flat rubber tube offers a more sophisticated odour control measure (von Münch and Winker, 2011).

The mentioned Figure 51, right, is this one (here a light bulb was used; I have severe doubts that this could work in the long term and am worried that the light bulb could break):

eco-lilly ethopia by Sustainable sanitation , on Flickr

I am happy to hear from others about their experiences with simple or complex odour control devices for waterless urinals or urine diversion toilets.

Regards,
Elisabeth