Worms, worms, worms... (vermi-composting for faecal matter)

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  • DavidAlan
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Re: Worms, worms, worms...

I have asked the questions. I will post when I receive answers.
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  • Marijn Zandee
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Re: Worms, worms, worms...

Dear David,

Thanks for the information from India, I have a few more questions to further my worm knowledge.

1.) Cow dung helps worms to survive, I would strongly suspect that is because the cow-dung is less compact and contains a lot more grass / straw residue. Have your colleagues in India also tried adding straw (or another carbon source) to human excreta and if so what did they find?

2.) For the human waste composting temperatures, did the mix contain the urine or was it feces only? I think that would have a significant impact on the temperatures because of the C/N ratio

Thanks

Marijn
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  • DavidAlan
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Re: Worms, worms, worms...

Ok, so now I have updated my details and it is clear who I am.

Thank you for the posts, they are very clear. For no other reason than for people's interest I show below the response I had from my colleagues in India, which reiterates much that has been said:

1. Generally most of the earth worms prefers a temperature between 15 and 20°C. Only the wild ones which are the African natives can survive beyond 20°C but not more than 30°C. The picture attached is a variety from West Africa and is called “EUDRILUS EUGENIAE”, which can survive with higher temperature up to 30°C, but the best condition is in around 25°C.
2. There are two phases of processes taking place while we are making compost – irrespective any wastes we use. The phases are a) Thermo phase and b) Meso phase. During the thermo phase the temperature inside the heap goes up to 30 to 35°C; during this period no worms can survive. Generally this phase is for about 45 days. This duration can be much less – say about 25 days provided if there is air circulation and watering is done. However, one can consider the meso phase starts after 45 days. During the Meso Phase, though there will be temperature inside the heap it is much less and between 15 to 25°C; which is the most suitable condition for the worms.
3. Generally the temperature in a heap of human wastes is more than any other organic wastes. It goes beyond 35°C in twenty days and remain for a week to ten days. Afterwards, gradually the temperature goes down to 20 to 25°C. The research conducted shows that adding a small quantity of cow dung makes a change in the temperature and it was observed the temperature is less than 25°C in forty days.
4. Further, it was observed that the survival rate of the worms is much better when cow dung is added with the human wastes.
5. The above mentioned variety is found to be the most suitable one to compost human wastes together with cow dung and the life period is 300 days.
6. For to compost one tonne human waste, 200 Kgs of cow dung will help the worms to survive and the composting process is much faster.
7. 3 Kgs of worms required to treat one tonne.
8. Compost will be ready in 3 to 4 months. More the aeration and under the shade faster the composting process.

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  • Marijn Zandee
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Re: Worms, worms, worms...

I agree with Christian's (or actually Elmer's) observation that worms can be quite picky about their environment. I am working on vermi composting of farmyard manures and somehow in one location it works fine and in another one not. If you can get them to work they are brilliant composters.

Another thing that should be mentioned is that according to the literature on worms the vermi composting does not destroy ascaris eggs, so it does not provide complete sanitation. This point was brought up by Christoph in the "benefit of dry feacal matter reuse-is it worth the cost/efford of processing" discussion on this forum.

Dear all,
just two aspects I saw in some previous posts and this last one.
a) some years ago I consulted an earthworm sepcialist because the subject was discussed - Ascaris is NOT destroyed by Vermicomposting. The eggs leave the "vermis" without damage. So vermicomposting does not make the material save.
the reference:
Edwards C A, Bohlen P J (1996) Biology and Ecology of Earthworms. Chapmann & Hall p.224
For instance, the eggs of Ascaris suum and Ascaridia galli passed
through the intestine of individuals of 1. terrestris without damage
(Bejsovec, 1962). In this way, the eggs are spread throughout the soil,
wh ich facilitates infection of domestic animals and birds. The virus that
causes foot-and-mouth disease can persist in the musde tissue of earth-
worms for 7-8 days and remain virulent.


b) treated drinking water (if not treated very badly) is ascaris free. A filtration is an effective mean to eliminate Ascaris.

Yours Christoph


Kind regards

Marijn
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  • DavidAlan
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Re: Worms, worms, worms...

Christian, surely you know I am David! That's a really good idea., thank you.

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  • christian.rieck
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Re: Worms, worms, worms...

Dear Alan,
I have just met with Elmer Sayre in the Philippines and he has a lot of experience on vermi-composting. It is like farming or breeding livestock - you need to feed the worms with what they like to eat in any ideal environment. If you do something wrong the worms just leave and disappear. Get in touch with Elmer through WAND Foundation.

An immediate solution to your problem would be to change the mode of operation of the UDDT from double vault to single vault with containers. Then you would not have to worry about the rate of filling, but remove or replace the full container as soon as it gets full. You would need to store the container for an additional time to dry up and then compost it or simply dispose it in the ground. Alternatively you can use plastic bags which allows you to empty the containers immediatly in a safe and confortable way. Just tight the bags up with a nod and finish. You should also further store the bags for several months. Elmer from the Philippines uses the bags after storage for coconut trees. He buries the bags in the soil, cuts or slits open the bag and covers with soil. That way you do not have to touch the material, thus transmission of pathogens is very much limited.

All the best
Christian

Cheers
Christian
GIZ Uganda
Enhanced Water Security and Sanitation (ENWASS)
Sanitation for Millions
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  • DavidAlan
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Re: Worms, worms, worms...

Thank you.

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  • cecile
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Re: Worms, worms, worms...

Dear Alan,

Generally, the best kind of worms is the one you will find close to the premises of you project in a compost heap. They are already adapted to the local conditions.
In France, users of urine diversion and vermicomposting toilets usually use Aesenia Foetida ("red worms" or "manure worms"). They are the most common earthworms in France.
Nothing is added to the feces (no ash, no sawdust).

Humidity is one important factor so when your composting heap gets too dry you need to add water.
Another important factor is that worms don't like Fresh feces. One possible solution is to creat 3 piles in your vault : one for fresh feces, one for vermicomposting and one for storage / maturation (if not enough space you couls store outside the vault). You can move the compost from one pile to the other every 6 months, depending on the space you have. You could check Ecodomeo 's website. They use vermicomposting as a composting technique. Check out their userguide in the "documents" section, it is very well explained.

Cecile
Cécile Laborderie
MAKATI Environnement

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  • DavidAlan
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Worms, worms, worms... (vermi-composting for faecal matter)

We have a pleasant problem where one of our community ecosan units in Sierra Leone is overwhelmed with users. It is a basic double chamber system (each circa one cu.m.) and the second chamber is filling before the first one is composted.

I thought that we should use worms to help the composting process, but of course the wetness/dryness will vary depending on the oldest/newest usage. Working on the premise that the worms will need to work on some quite wet faeces can anybody tell me the best species of worm to use?

Thank you for your help.
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