The 'samples' were of wood shavings as they said in their post and can be seen in the bags. Correct me if I'm wrong here.

Looks like the unit can take 1-2 cubic yards of wood shavings and sawdust (similar to other color compost toilet chamber brands), which is usually shipped dry (light weight). Lets assume there is 500kg of dry wood product as a starter. Moisture is 30%. It can absorb up to 70% moisture before it hits its saturation point and starts letting black water down. So the plug of wood could hold an input of about 550kg of water (urine) before it started leaching. At a generation rate of 0.2l urine per user, this is around 3000 uses to load the system to its saturation point. How many users use the toilet per year currently? Once at the saturation point, the material will change in character. After the 1-2 cubic yards of saturated wood shavings are removed, then you get down to the feces mixed with saturated wood (urine saturated) and this this is the third phase of the toilet (finally in full operation). This can take many years at low use sites. Then this is the 'compost' which I sampled in the 10-12 units throughout North America in 2010-2012; all samples were wet (urine), very high ammonia, high E.coli, looked like turds coated in wood shavings. If people don't use the toilets to pee, and pee on trees instead, and don't use that much woody stuff, the system would work much better (less waste mass and better decomposition). For sites used heavily for urination there is an excessive need to add bulking agent to soak up the water lest it just become a soupy mess, but this does not resolve the excessive nitrogen issue, and the biochemical pathway results in ammonia generation which is pretty much toxic to the mesophilic decomposer organisms (bugs or otherwise) that would consume the feces and wood. The nitrogen is all highly available but the carbon in a chunk of wood is not very 'available' or interesting and does not get used well in mesophilic temperatures.

Excerpt:
"For the real eco-sanitation geeks, you may be interested to know that these first samples were taken from what could be called the “starter” or “pre” batch – the chambers were initially filled with wood chips and shavings to provide a base of carbon material upon which to build the compost. This is to say that the test results for this first round may not be representative of what future batches will look like because these will likely contain a much higher ratio of total carbon."

My reading of this is that these are minor problems, bureaucratic and the like, and the real tests will be the results in a few years time. We must remember that the alternative to "composting" toilets is the flush toilet and these, whilst being mainstream, are no real answer. You never see the results of tests by municipal authorities (if any) of the "quality" of what is dumped into our Oceans, forgetting the ever increasing value of water used to flush.
I am encouraged by this report.
Ross

I found the following, which arrived earlier today in my inbox, particularly instructive/insightful:

oaec.org/first-compost-toilet-research-samples/

Here's a highly motivated group of people with all kinds of resources available to them and, still, they run into all kinds of problems with a mass-produced (so-called) "composting toilet". If these folks encounter the problems they did, just imagine what the general public goes through when trying to manage a non-source separating waterless ecological toilet.

Greetings all,
As a very recent subscriber to SuSanA, I invite people who are taking part in this interesting discussion to comment on sketch plans for a Clivus Multrum type of toilet. With very dodgy internet and few resources Timor Leste is not an easy place to work from.

My thread is at , forum.susana.org/241-composting-toilets-...ion-from-timor-leste

With lots of building experience but little in the finer design points of dry toilets, your input is of great value to me.
Cheers Keith Schekkerman, Timor Leste, Baucau.

I/we (NatSol) have always assumed that thermophilic composting was less reliable than long term mouldering because of the difficulty of ensuring all parts of a pile get to temperature – unless, of course, a more industrial approach is used. However, I fully accept that long term mouldering will not deal with helminths.

Ok maybe he's changed his tune. It was a while back I read his book in fairness.

Anyway, it doesn't really matter - he still apparently advocates a basically random addition method with no monitoring. Without having a good idea of the C:N ratio and without proper monitoring of oxygen levels and without a programme of regular turning, it is still guessing.

Which still isn't a way to do faecal composting. It is still to advocate magic.

I read one of Joe's first books and he describes failures within "composting toilets" (as in boxes under toilets that were magically supposed to hit the key criteria for thermophilic composting). I didn't know he moved towards support of the magic reactor black box. My biz partner spoke to him at one point, and he was very much more about making a good mix of stuff with a shovel before 'composting' efforts were applied.

Geoff

To get hot composting temperatures, the C:N ratio must be within specific values and there must be sufficient oxygen to allow the thermophilic microbes to grow.

Even if sufficiently high temperatures are achieved within part of a heap or windrow (usually easily achievable in the top-middle), the challenge is to ensure that all of the faeces has reached temperature.

So with the high amounts of carbon, sufficient oxygen and the necessity to turn the material, it is impossible to imagine anyone doing this reliably without any monitoring equipment. Any material produced in this way would need microbial testing to show it was safe. I highly doubt it would be.

It is beyond imagination to think it could be done in a space below a toilet without any oxygen or proper accounting of carbon and nitrogen.

The only part I disagree with Geoff is the idea that Jenkins talks about secondary treatment. In fact he goes to great lengths to try to prove that collecting faeces in buckets with chippings will compost into safe material.

Anyway, I have no interest in further discussing Jenkins or his misguided ideas.

I agree fully with Joe.

Urine diversion toilets are not so high on their horse to imagine poop doing much other than drying a bit in a UD DT. This is why most don't pretend with a facade of 'composting' in front of their name.

We are debating about the definition of compost again. It has been defined in the USA as something that is safe, stable, having been through thermophilic temperatures, with monitoring. Boxes under toilet hole will never achieve this.

Composting toilets are a misnomer.

Composting mixed human waste, after, separately, is Joe Jenkins style, and can be done well. This is the composting of human waste.

Vermicomposting does not destroy hook worm ova or render them in-viable.
www.researchgate.net/publication/2557338...micomposting_toilets
Other paper attached here for non commercial means.

Verimicomposting does not make compost. No high temperature step.


Geoff

Well they are systems which collect material below toilets in a confined space with regular additions of carbon rich material. Without any temperature or any other kind of monitoring.

That is what most people understand as a "composting toilet".

It is fairly clear from Save's work that the toilets in question are neither "dehydrating" nor "composting".

And it further seems to follow that "ecosan" systems designed in this way are therefore not reliable ways to sanitise faeces, whether they are said to be "dehydrating" or "composting" - functionally it makes no difference.

I feel like I have said it before on this thread - but it is much like making beer or cheese without any understanding of the microbiological and physical systems involved - in spaces where it is plainly impossible and where studies show it cannot work - adding random amounts of ingredients and then imagining that a product will come out the end that is not actually lethal.

Yes - the product needs to be safe. Whatever the system is called and whatever magic is supposed to be happening, if it doesn't produce a safe product it is useless.

We can call it whatever we like, but faeces plus carbon in a confined space beneath a toilet does not make a safe product. Ever.

Thanks, Joe, for your quick response..

I agree that Save Kumwenda's work is very interesting and detailed but it does not relate to composting toilets, but to UDDTs which he sometimes also calls ecosan-toilets. UDDTs are NOT composting toilets as the name says. They are 'de-hydrating' toilets which in my understanding is a different process, or?

I understand 'composting' is the degradation of organic matter at specific temperatures, moisture content and under aerobic conditions.

But maybe 'composting' can also be described by the product which comes out of it where I would not know how to describe it. But then the de-hydrated faeces from an UDDT can eventually be named as 'compost' which is why some people call it a 'compost' toilet?

Therefore I am also not sure whether vermi-digestion can also be called vermi-composting because eventually the resulting humus falls within the material description of compost?

Nevertheless, I think not enough research has been done to evaluate the safety of vermi-composting. We had a discussion in a different thread here about the topic. And in spite of the many research sources quoted by Prof Rajiv Sinha in his two papers, I am not sure about the safety of the humus from vermi-composting.

ciao
Hajo