There was quite an interesting discussion lately on the ecosanres discussion forum which is run by SEI. For me, I find it a real pity that that particular discussion forum is closed and only e-mail based, so I have asked Ralf Otterpohl if I can copy his recent postings across to here so that they are out in the open and can be re-found more easily. Ralf is a well-known professor in Germany (Technical University Hamburg-Harburg) who has published on ecosan topics since several decades and whose current main interest is in Terra Preta Sanitation.
(I didn't copy the other responses, not because they are not good as well but because I haven't asked the particular people yet for their permissions)
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On Apr 3, 2012, at 8:32 PM, Ralf Otterpohl <ro@...> wrote:
Dear Carl,
Dear All,
I agree in long term separation of above 10 years until no crop restrictions apply. However, in many cases the excreta compost can be highly beneficial to help reforestation, to create beneficial trees that avoid land erosion and provide fodder, later even food. Moringa Oliveira trees are amazing in multiple benefit, the leaves are great fodder (up to 40% for goats fodder see reader in
www.anamed.net), seeds useable for greywater precipitation or drinking water purification. At the same time roots build humus in the surrounding soil improving yields, too. After 10 years in excreta compost leafs can also be highly nurishing food, the taste after being cooked is like mangold/swiss chard and spinach. Unfortuntely only in the warm climates. Such concepts with Moringa (not yet the excreta compost I guess) are used in Ethiopia in the South West in a really dry region with great success. With this goats could be kept in fences thus allowing re-growth of natural and man-made vegetation.
Further great trees are Neem (besides 40 great benefits to man excellent goat fodder see ANAMED) and we should look more for the Annatto Tree (Lipstick-Tree), it has the potential to provide nutrition for humans yielding as much as intensive wheat fields on the same area but restoring it at the same time and allowing veggie production under them, too. Compost is very often urgently needed to get trees tall enough to survive the growth phase. The Composting Group in Arba Minch (involved in EU CLARA project of Gunter Langergraber) does apply this 'trick' to sell compost, you buy a bag with a small tree and buy 3 bags of compost with it to have it growing.
For sanitisation: Lactic Acid Fermentation is highly efficient even before the composting in the toilet, good thermo-phase later followed by vermi-composting is pretty safe - plus 10 years of crop restrictions for hygiene and wash out of micro pollutants. We will get high amounts of compost when we also compost urine with woody waste (200 kg/person /year allow evaporation in between) and even better with addition of some charcoal. See
www.tuhh.de/aww for many downloads of over a 100 person years of intense practical ecosan research including vermi-composting.
Kind regards
Ralf
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On Apr 10, 2012, at 11:26 AM, Ralf Otterpohl wrote:
Dear Carl,
The great thing is that we have so many options at hand that all have their upsides and downsides. Your system has some clear advantages, no doubt.
Improving soil is the thing to do to assure the base for water and food security, therefore we work on systems that produce maximum humus also from urine. Not from the desk but with lots of practical applications. The diffence may be that we work on developing professional systems that can serve millions at low costs. Densely populated areas are often not all that suitable for huge chambers. The collection effort for excreta and urine in the peri-urban and urban is that same as urine dominates volume. Composting in our approach is ideally done where the humus is used (non-food for the first ten years), where the soil is, as transporing twice does not make a lot of sense.
Kind regards
Ralf
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Re: Compost for Trees Re: EcoSanRes: Composting Reduces Growers' Concerns About Pathogens!
Dear Richard,
Dear All,
Everybody is free to use more or less well sanitized excreta for his or her own food supply. The risk is low in this case, as an emitting person will just infect a person taht is ill already. For professionals in sanitation we cannot do so because we do have a certain risk of spreading nasty diseases. This is unneccessary because we can grow our food with the kitchen waste and utilize excreata compost non-food eg for planting trees.
One pathway that is not considered even by hygienists (obviously there are many people also overdoing this issue..) is the uptake of bacteria through roots of vegetables. This pathway is called endocytosis in plants and very well proven by respected universities. E.g. E-Coli has been found to move inside the plant alive until it will be digested at some time. Now I will not put anybody at risk by implementing systems where there is a pathway shorter than 10 years from toilet to vegetables.
In Germany we have had severe incidents with EHEC - where there are species of E-Coli that are deadly. The victims in Germany last year ate sprouts from seeds that had been watered with wastewater. Richard, when your secretary, who likes your spinach from the toilet compost falls ill, you will be responible at least morally. In the school of my children we just had an EHEC warning, this is not so rare as we may think. And there is a lot of pathogens around.
If we as Ecosan community want to be taken seriously as professionals in sanitation we must get away from unnecessary risks. Almost everybody around the world does hate to eat veggies from toilet compost (almost always at far too low temperatures) and I cannot follow the obsession some of us have for promoting exactly this. Excreta compost is so little that we can easily keep it separate and bring to the ecological loop in a longer time span. Many people are repelled by the nice drawings from toilet to mouth, few will tell us.
I do respect your motivation and your good work, but flexibility and adaptation is something great. Let us move to the safe side where the health and lifes of others are can be affected.
Kind regards
Ralf
Ralf Otterpohl
Univ. Prof. Dr.-Ing.
Director
Institute of Wastewater Management and Water Protection
*** focus on Resources Management Sanitation / Ecosan
TUHH Hamburg University of Technology, Germany
www.tuhh.de/aww