Dear Hajo, dear cecile, dear Prof. Otterpohl,

thanks a lot for your answers and information and sorry for my very late reply now.

a) I was asking this questions since there was a competition on this topic and I wanted to know what the SuSanA community thinks about it.
You find the competition here: www.gcsm.eu/gcsm_award.html

b)Because I had so much work I had to stop thinking about this model, unfortunately. But you can find the contributions of the other groups on the same webpage: www.gcsm.eu/gcsm_award.html

c) The only important fact I realized is what also Cecile pointed out: There are so many things to consider that it is just not feasible to have a generel model for something like this. I also like the idea of learning from good and bad solutions from the same region (because of all the variables) first and then try something out and improve it. Upscaling is for later...

Best,
Georg

hello Georg,

have there been any further developments on your TPS model for 20,000 people and possible lessons-learned which you can share with the forum users?

How did you finally answer the questions for your model which you had posted on the forum?

I am asking as I have very similar questions thinking about sanitation solutions for 100,000 people.

ciao, Hajo

Dear Georg,

There was an interesting discussion about vermicomposting in this forum here
forum.susana.org/forum/categories/70-com...01-worms-worms-worms

If you type "lombristation" in google you will find documents about a vermicomposting waste water treatment company (called Lombritek )
There is one station working in the south of France (you can find documentation about it in SuSanA's library). The technology was developped to treat waste water of 2000-4000 people but the company is currently developing a system to treat sludge before treatment in WWTP for 2 000 to 20 000 people.

Finally to answer your question, vermicomposting or thermophilic composting,I would say the answer is not so much which technology is better, but what do you have to treat in the first place(caracterisation of the "waste"), climate, space, budget and ressources (know how). This may be not very satisfactory for modellisation but from my point of view it is difficult to answer this kind of question from a theoretical point of view.

By the way, is there a reason for the figure of 20 000 people in urban community ? In France, "innovative" sanitation systems (vermicomposting, constructed wetlands) are usually tested for 5EH (person equivalent), then 20 EH, then on small municipalities 200-5000 before being upgraded to larger treatment plants.

Kind regards,

see myanswer in
forum.susana.org/forum/categories/17-fer...sion-or-no-diversion

Dear Sanitation Experts,

my name is Georg and I am very interested in Terra Preta Sanitation (TPS). A good overview about the system can be found here .

I am trying to model a suitable, exemplary TPS system for a community (urban area) of 20000 inhabitants, which means a municipal collection and treatment of excreta should be possible.

While most researchers agree that charcoal is necessary for the formation of Terra Preta, still many open questions remain in my mind and I would like to share them with you. I hope the SUSANA community will be able to shed light on this issue.

Question 3 can be discussed here. For the discussion of questions 1 and 2 please follow the links below.

1. URINE DIVERSION OR NO DIVERSION?
2. LACTIC ACID FERMENTATION (LAF) OR SIMPLE COLLECTION (SC)?
3. VERMICOMPOSTING (VC) OR THERMOPHILIC COMPOSTING (TC)?

3. VERMICOMPOSTING (VC) OR THERMOPHILIC COMPOSTING (TC)?

	most TPS experts propose: Vermicomposting (VC)	an alternative: thermophilic composting (+VC)
pro	[FACTURA ET AL. 2010] - kills most pathogens (indicator bacteria) - “fast” procedure - good structure of substrate formed by worms - even better desinfection in combination with Lactic Acid Fermentation	- scientifically proven that it can kill ALL pathogens (including Ascaris eggs) [ JENKINS 2005, chapter 7 ] - earthworms are also involved after the hot stage to further sanitize and stabilize organic material [JENKINS 2005, e.g. p. 67]
contra	- some evidence that VC is not enough to kill ALL pathogens (e.g. helminth eggs [ COLLENDER 2013 ; BOWMAN ET Al. 2006] ]	- higher emissions in nitrogen and carbon - might take longer - more control over temperature needed (can be done by municipality)

What do you think is the most suitable TPS system for a 20.000 people urban community?