Very clever solution - best dry solution I have seen up to now

  • christoph
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Very clever solution

Dear all,
I came across this dry sanitation solution. I consider it the best thought solution I have seen up to now. WHY?
It fulfills the various aspects I am always searching for.

  1. As the "older" users of you might know, I am always in search of solutions for a dry sanitation service for densly populated areas. I think the presented solution in the video below is a nice possibility. A two chamber system gives the possibility to put the second chamber on the road side, pass by with a truck and exchange or empty the chamber. So a totally clean solution with a partially stabilized material.
  2. Many people don´t like to look in the hole and "see stuff". The crank solves that problem.. VERY nice.
  3. In Lima many of the households without sanitation are of difficult acesss. The light weight solution makes transport easy. We always had trouble in constructing. Or it is slow (as you build) or it is too heavy (we tried prefabricated concrete construction) or it is only a one chamber system. So this solution seems to have large potential.
  4. No high technology.
  5. Possibly an economic solution (I don´t know the price).
I know the people who have developed the system. They work on the subject since many years and have large practical experience.

So have a look and enjoy.



Regards
Christoph
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  • hajo
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Re: Very clever solution

Hi Christoph,
thanks for sharing this with us, every other sanitation solution makes us think about alternatives or confirms our approach. I fully share your ambition to find sustainable sanitation solutions for the high density peri-/urban areas in our respective countries. But I fail to understand the very specific advantages of this solution - maybe due to my lack of Spanish.

Let me quickly summarise how I understand it: the toilet is prefabricated of plastic and is a UDDT, it has two faeces chambers on top of the other, a crank mechanism moves the stuff from the upper chamber (presumably through a hole in its floor) to the lower chamber which contains a removable container which can be exchanged/emptied when full.

My comments: the light plastic definitely is an advantage as indicated by you. With the crank mechanism I wonder whether it is so efficient that all stuff vanishes, is there not a possibility that faeces and/or toilet paper stick to the 'propeller' and will still be seen by the user? Is it not even possible that the 'residue' on the propeller eventually builds up and requires manual cleaning? The removable container is not really new, even 'your' bench UDDT has it. But I agree that the removable container is one 'trick' which can make a UDDT service chain sustainable.

greetings to Brazil,
ciao Hajo

We can't solve problems by using the same kind of thinking we used when we created them.
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  • arno
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Re: Very clever solution - best dry solution I have seen up to now

Hi Christoph
Thanks for that. It's a great idea and eliminates the daily problem of having to flatten the heap in a shallow dry bucket collector. I couldn't quite see the openings to the larger container below the propeller. They could become a source of clogging and thus requiring occasional dismantling and cleaning. Also paper could also get wound around the axle or remain stuck to the blades building up resistance. Regarding ventilation, the upper drum would need to be ventilated as much as the lower container in order to enhance drying.

Any idea how many have been installed?

Best wishes

Arno Rosemarin PhD
Stockholm Environment Institute
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  • christoph
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Re: Very clever solution - best dry solution I have seen up to now

Thanks Haio and Arno for your replies. Some answers:
  • Arno you got it quite right, the propeller is to get a better use of the first chamber, to have an intensive contact of the drying material and not to have a build up in the middle. The solution has been tested for one year and is going in roll out right now from what I understand. Therefore I guess the number of installed toilets is low until now (about 30 in use). The interesting point of the propeller is, that you have a nice solution even with a low chamber hight.
  • The point you mention of ventilation for both chambers is as well an important aspect which was solved in the project.
  • The paper aspect might be a problem which has not be seen up to now, as in Peru the paper does not go into the toilet.
  • Arno and Hajo - what did not become clear is that the transfer from chamber one into the second chamber is not through openings or with a srew typ funcion. You push the handle (see yellow arrow pointing to it), when turning the handle gets heavy. So it is manual by decision of the user.


  • Hajo - concerning " Is it not even possible that the 'residue' on the propeller eventually builds up and requires manual cleaning?" This has not been a problem in practice until now.

  • About the aspect "the removable container is not new" - certainly not. What is new, is that the compact form is able to store the feces for at least 4 often up to 8 weeks, therefore you need a service just once a month (quite cheaper than the weekly collection in other concepts with removable container). This storage enhancement in low volume is possible, as the drying is much more effective due to the probeller and the mixing. And in contrast to a "our" bench systems it needs much less space, as you don´t have to change over to a second chamber. I think THAT is the clever trick.

  • Cheers
    Christoph
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    • canaday
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    Re: Very clever solution - best dry solution I have seen up to now

    Hi Christoph and everyone,

    This interesting system is basically the C-Head
    www.c-head.com/
    with the addition of the lower chamber (and thus the need to extend below the floor of the room.)

    It would be nice to see how pushing that button makes the material fall to the lower chamber. It may be good for some sort of flag to be raised by this mechanism, thus advising those who do the maintenance that there is now material to be removed.

    Various cover materials could be used and (as I have mentioned before) I would recommend using finished decomposed feces (after storage during a prudent period of time) mixed with maybe 50% bulky natural material that does not break down quickly, like bits of biochar, rice hulls, egg shells, etc., to allow more oxygen to get into the pile and to keep it from clumping and clogging. This reuse would inoculate fresh feces with beneficial decomposer microbes, reduce the monetary and environmental costs of acquiring and transporting so much material, and greatly enhance the stand-alone, off-the-grid aspect of this system. Remember that, with the mixing, there will always be some small percentage of fresh feces on the top, so why not some fully decomposed feces? Also remember that 90% of the nutrients are in the urine and essentially all the health risk is in the feces, plus the nutrients in feces are not getting lost, but rather stored for some future use. Further remember that feces mainly consist of water that evaporates off and microbes that proceed to eat each other, thus the feces will not increase very much the volume of recycling material and that little bit of excess can go to the garden.

    How much do these toilets cost? Can they be shipped to Ecuador? How many are in use? Have you had the opportunity to use one?

    Best wishes,
    Chris Canaday

    Conservation Biologist and EcoSan Promoter
    Omaere Ethnobotanical Park
    Puyo, Pastaza, Ecuador, South America
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    • NancyGilbert
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    Re: best dry solution i have seen up to now

    Christoph, who manufacturers this, where is it available and how can we get more information about it? We're really interested and have lots of questions:

    How has it been accepted, used. How does it smell? How much of what dry material is added to the upper chamber? Urine diversion? How long does it take to fill the upper chamber? What are (and what best should be) the characteristics of the mixed material when it gets dumped to the secondary composting chamber? What are the characteristics (ideally and in practice) of the material removed from the secondary chamber? What do uses do with that 'finished' material. Helminths?

    Thanks a million,

    Nancy (This email address is being protected from spambots. You need JavaScript enabled to view it.)
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    • StewMartin
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    Re: best dry solution i have seen up to now

    Having seen a number of mechanisms to move feces into another container ... I would have less faith in this propeller than others. Why not a simple reinforced blade that matches the shape of the primary box, moved using a hand lever with a sleeve bearing. It would push the feces into a box in the back?

    Also, I'd want to see a cover with a latch on the removable box, so no one spilled anything on their journey to the collector or collection site.

    The objections are usually don't want to touch, smell or see feces ... and I don't see how this assists much compared to other designs. It's not easy to make this, so it would probably be confined to cities with manufacturing facilities, not usable in rural villages. Price, ease of use and no-clog, no-smell and no-repairs needed will be key concerns.

    Stew Martin
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    • JKMakowka
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    Re: best dry solution i have seen up to now

    StewMartin wrote: Having seen a number of mechanisms to move feces into another container ... I would have less faith in this propeller than others. Why not a simple reinforced blade that matches the shape of the primary box, moved using a hand lever with a sleeve bearing. It would push the feces into a box in the back?


    This thread does a very bad job explaining the actual mechanism.
    The rotor is not really used to move the faeces, but rather to stirr-up the dry material in the upper chamber so that the faeces disappear from sight.
    Think of it a bit like a cat litter box ;)

    Krischan Makowka
    Microbiologist & emergency WASH specialist
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    • christoph
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    Re: best dry solution i have seen up to now

    Dear all,
    sorry for the late reply.

    @Nancy – wow – many questions. Let´s go:

    a) you can order it with
    http://www.arrebolperusac.com

    b) “How does it smell?“
    It does not smell – that is the whole point. 1) due to the good ventilation and a aerobic process
    2) due to the urine separation the feces keep dry 3) by the intensive mixing the feces dry faster

    c) “How much of what dry material is added to the upper chamber?”
    I did not use it, but what I know it is quite less than adding material after each use.

    d) “urine diversion? “ – Yes

    e) “How long does it take to fill the upper chamber?”
    Depends on the use - about 2-3 weeks.

    f) “What are (and what best should be) the characteristics of the mixed material when it gets dumped to the secondary composting chamber?”
    When turning the handle gets heavier it is time to dump the material.

    g) “What are the characteristics (ideally and in practice) of the material removed from the secondary chamber? What do uses do with that 'finished' material. Helminths?”
    I will answer your 3 questions together. You have the first step stabilization process when the second chamber is full. You get a material which is well mixed with the sawdust. The material is in perfect condition to be transported to a secondary treatment – for instance composting to get rid of Helminth eggs.

    h) Sorry I missed this question "How has it been accepted, used."

    The roll out of this solution is just starting, but pelase ask arrebol directly. What I understand the reception is very good.

    @ Stew Martin
    As I explained in my second post, the mechanism to dump to the second chamber is exactly as you point out “a simple reinforced blade that matches the shape of the primary box, moved using a hand lever with a sleeve bearing.”
    And I agree with you that “a cover with a latch on the removable box, so no one spilled anything on their journey to the collector or collection site” is the perfect solution when you have a collection.

    The price is about 500 U$ (in Perú).
    As there is no “transport mechanism” there is no clogging.
    No smell I answered to Nacy above.
    And well - no repairs – that is a dream. But certainly very robust.

    Just to make the thread a bit clearer I attach a video with a potato so don´t be afraid do look.:woohoo:

    Regards
    Christoph
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